,^ x .....°^ ^ http://www.archive.o^ '- ^ ■>'■>, The Colorado Potato Beetle Insects Injurious to Vegetables By F. H. CHITTENDEN, SC. D. United States Department of Agriculture ILLUSTRATED NEW YORK ORANGE JUDD COMPANY LONDON KEGAN PAUL, TRENCH, TRUBNER & CO., Limited 1907 LIBRARY of COWGRPSS Two Coole? Received OCT ii isor Cooyriffht Entry A up fc ffc7 CLA XXc,, NOi COPY B/ Copyright 1907 BY ORANGE JUDD COMPANY y4// Rights Reserved Entered at Stationers' Hall I,ondon, England PREFACE Among the hordes of insect foes with which the American farmer has to deal, those affecting vegetable crops are in many- respects most troublesome. Vegetable plants are exceptionally perishable, and the control of their insect enemies entails a very considerable expenditure of money and time. The an- nual losses due to insect attack on vegetable crops is esti- mated at 20 per cent., or double that of the average farm crop. The injurious vegetable-feeding forms outnumber in species the insect enemies of any other single class of crops, excepting possibly deciduous fruits, and this nearly endless variety of pests necessitates information in regard to each. Many are intermittent in attack, hence the grower should be forewarned in order to guard against injury or to check it before irrep- arable damage has been accomplished. The progressive veg- etable grower should be as amply equipped with knowledge as the fruit grower, and if he would be entirely successful in avoiding losses from insect ravages he should be provided with a complete outfit for spraying operations and should keep on hand or know where to obtain at short notice a good supply of necessary insecticides. The more general observance of certain farming methods with a view to the prevention of in- sect injury will greatly lessen the losses from this source. Until within recent years few farmers in planning the manage- ment of the farm for the season considered the effect which any given method of tillage would have upon injurious insects. Too frequently they fail to look far ahead, and as a rule ro- tation of crops where practiced is more for the sake of soil improvement than for the avoidance of insect injury, and yet crop rotation is the best and sometimes the only remedy for VI PREFACE certain species of insects. Among other general methods of farming strict cleanliness, including the destruction of weeds and burning over fields after harvest, fall plowing, crop ro- tation, the use of fertilizers, and the selection of the proper place and time for planting, must be considered. A knowledge of the classification of insects sufficient to enable the farmer to distinguish friends from foes is valuable, and finally comes a knowledge of what insecticides and repellents to use and the best means of preparing and applying them. Accounts of most of our noxious species of insects have been published. These accounts, however, are distributed through government and state publications, reports of agricultural so- cieties, magazines, and periodical publications of entomological societies, and even the daily press. As an example of the number of such publications on American economic ento- mology, the Bureau of Entomology, United States Department of Agriculture, has cited no less than 12,645 titles that had appeared to January 1, 1905, and the number of references to noxious insects is about 72,000. The average farmer has neither time nor opportunity to consult a tithe of these 12,- 000 odd works, and it is therefore the object of the follow- ing pages to collate concise accounts of the principal insects which affect one class of crops — vegetables. The order which will be followed is, as far as practicable; alphabetical, begin- ning with the insect enemies of asparagus, and ending with those which affect sweet potato, and finally miscellaneous or unclassified crops. The insect enemies of vegetables have not hitherto been con- sidered as a special topic in comprehensive form. Separate accounts, however, on the economic entomology of certain vegetables have been published, for example, of beets and of sweet potato. In presenting this work to the public its author does not claim originality for its contents. It is, however, largely com- PREFACE Vil piled from his own writings, although it has been found necessary to draw also from the works of others, and is based on an experience of about ten years with the subject with which it deals. The illustrations are in large part the same, or adaptations of, figures previously used in the Bureau of En- tomology, United States Department of Agriculture, and are so credited. F. H. Chittenden. United States Department of Agriculture, September, ipo/. CONTENTS PAGE Preface . . . v-vii Introduction . . . x-xiv 1 CHAPTER I Value of a Knowledge of Entomology .... 1-15 General considerations — Classification of insects — Orders of insects — Natural elements in the control of insects. CHAPTER II Prevention by Farming Methods . . . . _ . 16-25 Selection of place and time for planting — The main- tenance of vigorous growth — Burning over fields and waste lands — Crop rotation — Diversified agri- culture — Fall plowing and cultivating — Clean farm- ing methods — Farm inspection — Cooperation in the control of insects. CHAPTER III Mechanical Methods of Destroying Insects or Prevent- ing Injury 26-29 CHAPTER IV Insecticides and Their Uses _ _ 30-48 Stomach poisons, arsenicals, etc. — Contact poisons — Insecticides which kill by suffocation — Proprie- tary insecticides — Insecticide apparatus — Remarks on applying insecticides. CHAPTER V General Crop Pests 49~9i Cutworms and related insects — Miscellaneous cater- pillars — Leaf-beetles — Flea-beetles — Blister beetles — Grasshoppers and related insects — White grubs — Wireworms — Aphides, plant-bugs and related insects — The red spider. CHAPTER VI Insects Injurious to Asparagus . 93-98 viii CONTENTS IX CHAPTER VII page Insects Injurious to Beans and Peas . 99-H9 CHAPTER VIII Insects Injurious to Beets and Spinach „ . . 120-130 CHAPTER IX Insects Injurious to Cabbage and Other Cruciferous Crops . . . ■■•.'• • •■ • • 131-154 CHAPTER X Insects Injurious to Cucumber, Melon and Related Plants 155-175 CHAPTER XI Insects Injurious to Celery, Parsnips and Related Plants 176-188 CHAPTER XII Insects Injurious to Sweet Corn . . . . . 189-212 CHAPTER XIII Insects Injurious to Potato and Similar Vegetables . 213-228 CHAPTER XIV Insects Injurious to the Tomato 229-234 CHAPTER XV Insects Infesting the Sweet Potato .... 235-243 CHAPTER XVI Insects Injurious to Miscellaneous Vegetable Crops . 244-251 The onion and other bulb crops — Rhubarb — Let- tuce — Okra or gumbo — Salsify — Pepper. CHAPTER XVII Bibliography . 252-258 Index . . . 259-262 INTRODUCTION Vegetables are subject to attack by insects from the time the seed is planted until the edible portion is ready for cooking. Insect injury manifests itself in different ways according to the plant attacked, the insect concerned, the stage of the insect, and the age and condition of the plant. Manifestations of Insect Injury. — If plants soon after the seed has been sown fail to appear in due time, such failure is apt to be attributed to unfavorable atmospheric conditions or to imperfect seed, but examination will frequently show that some insect is at work. Among insects destructive to planted seed are wireworms and root-maggots, and in some cases insects that have fed on the seed stock while in store are planted with the seed, and this they destroy by eating out the germ. Familiar ex- amples are the bean and pea weevils. Asparagus tips when ready for cutting are ruined for market by the asparagus beetles (see Fig. l— Aspara- **£• I ) * ^ plants like tomato that are reset are gus tip, showing cut off abruptly near the ground, cutworms are by asparagus near ty always at work. If the minute leaves of beetles. (Au- plants like cucumber, soon after beginning to thor's illustra- . , • i i tion, u.s.Dept. sprout, are found eaten away, causing the plants A § r) to die, cucumber beetles are present. Corn is similarly affected by flea-beetles, as are also potato and other vegetables. When stems or stalks of various plants are found with one or more holes of varying size, from that of a straw to con- siderably larger, this is evidence of a borer within, particularly INTRODUCTION XI if excrement is exuding. Common species which do this in- jury are the common and corn stalk-borers and the grass- worm. When plants like corn make unequal starts, a hill here and there showing greater thrift than elsewhere, injury is apt to be due to root-aphides. As a rule, these insects are ac- companied by ants, which in most cases foster the "lice," and sometimes feed on the seeds. When the leaves of plants are seen to be withering, and aphides or other sucking insects cannot be de- tected above ground, search will usually reveal the presence of white grubs, wireworms or other insects working below the surface, and the same is true of corn plants that fall after windstorms, root-worms also being present at such times. Another manifestation of the presence of root- worms is in the plants requiring too long a time for maturing, and producing sterile stalks, and, in the case of corn, yielding nubbins instead of complete ears. When young leaves are found with small round holes of about the size of a pea or a little smaller, leaf- Fig. 2.— Bollworm entering bean pod, Somewhat enlarged (Authors illustration, U. S. Dept. Agr.) beetles are usually present, while much smaller holes occurring in great profusion over leaves usually betoken the presence of flea-beetles. Extremely large and irregular holes in leaves of older growth are made by grasshoppers, crickets, and the larger caterpillars such as "woolly bears." Fruits such as melons are attacked by the melon worm and pickle worm; tomato, beans and corn by the bollworm, tomato Xll INTRODUCTION fruit worm or ear worm (fig. 2), and the edible roots of such plants as beet and carrot, are subject to injury by the carrot beetle, while potato tubers are damaged by the potato tuber worm. Seed pods and similar coverings of seeds are attacked by numerous insects, such as the corn ear worm, cu- cumber beetles, and others. Growing seeds are liable to be injured by some of the last mentioned insects as well as by some others which begin development when the seed approaches ma- turity. Familiar forms are the bean and pea weevils, and the Angoumois grain moth. Many other forms of injury might be cited, but it may suffice to briefly mention the curling and dying down of leaves like melon, due to the presence of the melon aphis; the wilting and dying of squash caused by the severance of the stalks by the vine borer feeding within; the discoloration of leaves such as radish and their subsequent drying, owing to leaf-miner attack; and the destruction of whole plants of various kinds by army worms and migratory cutworms. Every year that passes brings with it some new entomolog- ical problem to be solved, and this is especially true of insect injury to vegetables. The cause is usually a general or local outbreak of one or more serious pests, and the species concerned may be an old and well-known injurious form; it may be a com- paratively unknown species or one that has not hitherto been identified with injury to useful plants; again the habits of the species may never have been studied owing to previous scar- city. It has perhaps lived in obscurity since time immemorial before any considerable outbreak attracts attention. It may be new to our country or even new to science. Determination of the Injurious Insect. — The first problem that confronts the grower whose crops suffer from insect in- jury is the identification of the insect. Most insects have popular names, more or less local, which may be apt or may be rank misnomers, conveying no definite meaning. INTRODUCTION Xlll Thus if a southern farmer complain of "the budworm," failing to state what plant is being injured, it is an impossi- bility to identify the insect concerned. The budworm of corn is the twelve-spotted cucumber beetle of the northern states, while the budworm of tobacco is the same as the tomato fruit worm and the corn ear worm or bollworm or a related species. The first pest is Diabrotica 12-punctata; the second is Fig. 3.— Diabrotica 12- punctata. (Riley, U. S. Dept. Agr.) Fig. 4.— Bollworm moth in natural position. About twice natural size. (Quaintance, U.S. Dept. Agr.) Heliothis obsoleta. 1 The parent of the first is a beetle (fig. 3) and of the latter a moth (fig. 4)-. It should be added that the first named species is also known as drill worm, while the latter is also called the shatter worm, this last name being shared also by the larger corn stalk-borer and perhaps by other species hav- ing the same habits, such as the fall army worm. The last is the grass-worm of the South and the fall army worm of the 1 It is to be regretted that the scientific names are not more stable, but the bollworm was generally recognized under the name of Heliothis, until it was recently changed to H. obsoleta. XIV INTRODUCTION North. It is the "alfalfa worm" of Kansas and Nebraska and elsewhere it is simply called the army worm. Its technical name is Laphygma frugiperda. It will thus be seen from the examples cited that the popular name of an insect has frequently little bearing on its identity. The scientific name must be determined. A frequent source of injury to plants is due to contiguous growers who raise the same, or similar crops, for different pur- poses, e. g., some may raise cucumbers for pickling, and in the immediate vicinity others grow melons for fruit, so that pickle-growers pick their crops while quite young, and the fruit-growers when older. This means that after the pickle- grower has stopped pickling, numerous vines remain, and the insects scatter from them to melon fields. Insects Injurious to Vegetables CHAPTER I VALUE OF A KNOWLEDGE OF ENTOMOLOGY GENERAL CONSIDERATIONS For an intelligent understanding of the subject of insect control by agricultural practice one must know not alone that certain conditions produce an increase or decrease of certain forms of insects, but how this is accomplished, why the alter- nation of one crop with another is apt to result in insect injury, and why a system of crop rotation that would be of value in the control of one class of insects might be ineffective against another; how fall plowing, though destructive to one species, would not affect a different insect, and so on. In short, a knowledge of economic entomology beyond the fact that arsenicals are the proper remedies for mandibulate or chewing insects, and that kerosene will kill aphides or plant- lice, scale insects, and other soft-bodied insects, is a prereq- uisite to intelligent effort in the control of noxious insects. Before we can hope to avert losses we must know what our insect enemies are, what species are destroying each crop, which ones are responsible for primary injury, which are sec- ondary or merely auxiliary, how injury is accomplished, when injury begins each year, when it ends, as well as other facts. Similarly desirable is it to be able to recognize useful in- sects, such as ladybirds, syrphus flies, tachina and ichneumon flies and other parasites, that these may not be unnecessarily destroyed, but, if possible, encouraged in their useful work. i 2 INSECTS INJURIOUS TO VEGETABLES The different stages of some insects are so diverse that they can be identified only by specialists, and many entomologists are unable to recognize them without reference to technical descriptions and illustrations. Some knowledge of the distri- bution and origin of a species is of value, as well as some acquaintance with its history and literature. A knowledge of the life history of an insect consists in knowing : when, where and how its eggs are deposited ; how the larva feeds, and how many stages there are in this period; the habits of the larva, whether diurnal or nocturnal, whether omnivorous or a dainty feeder; how and where it transforms to pupa; how and where and in what stage it passes the winter; the number of generations produced each year; the first appearance of the insect and its disappearance, and the same of each generation; its food plants, natural and culti- vated, and above all, its favorite foods, both as larva and adult. If to this we add a knowledge of the effect of farm practice and of insecticidal and mechanical methods on the insect we have, in a general manner, the main facts desired. We must determine in what stage and at what time the insect is most vulnerable, and by practice and experiment learn the best remedy. A knowledge of the appearance and place of deposition of the eggs will, in the case of some species, furnish means for their control, for many insects can be combatted successfully merely by destroying the eggs. Others may be killed in their cocoons. The most valuable weapon that can be used in combatting an insect consists in an intimate knowledge of the insect itself and its life economy, its natural enemies, its susceptibility to natural influences, heat and cold, dryness and moisture, and their effect upon its increase or decrease directly, or indirectly by destroying or favoring the growth of its enemies. A knowledge of the weeds and wild plants that furnish food for these insects, in addition to cultivated plants, and the soils in VALUE OF A KNOWLEDGE OF ENTOMOLOGY 3 which they attain their greatest development is also desirable. To this we must add a knowledge of the effects of different farm practices upon the insects, as well as of insecticides, There are many insects with which we cannot cope by the use of poisons, and it is only by a thorough knowledge of their life economy from the time the eggs are deposited until the perfect insect emerges, that we are able to mitigate losses from their ravages. The knowledge of some one or more facts appar- ently trivial in themselves may frequently enable us to pre- vent by farming methods injury which we cannot cure by means of poisons, mechanical or other direct methods After seed has been selected with reference to its adapta- bility to the soil and climatic and other conditions one of the next problems that confront the grower is how to protect the crop from noxious insects and diseases. Fortunately we know approximately the life history and habits of a large proportion of the injurious insect inhabitants of this country, with the exception of some few species which have only been recently associated with injury, or which have lately been introduced from abroad. As a necessary preliminary to the discussion of the insect enemies of the various vegetable crops, some idea of the struc- ture and classification of insects must be given. It is perti- nent to follow as a matter of course with general methods of control, which include (1) mechanical methods, (2) farm prac- tice as preventives and (3) the preparation and means of applying poisons for the destruction of insects. Following this the different groups of insects which affect various crops and are not attached to single crops will be considered. CLASSIFICATION OF INSECTS If we would have an intelligent understanding of the causes that have led to the destruction of our crops, we must know something of the classification of insects and their nearest rel- INSECTS INJURIOUS TO VEGETABLES atives in order that we may be able to distinguish friends from foes and true insects from related forms. It is, of course, not essential that all of the Latin names which insects bear should be memorized, nor that anything approaching a complete classification be studied. The object of what is here presented on this topic is to assist in the ready identification by orders of such creatures as may come under observation as enemies or suspected enemies to plants under cultivation. It is first desirable to eliminate animals which are not true insects but are related to them. These are all included (with true insects) under the branch Arthropoda of the Animal King- dom and are distinguished by having their bodies composed of rings or segments more or less similar, joined together, most of them bearing jointed legs, the last character separating them from earthworms, eel-worms, or hair- worms, which have many segments but no legs. This branch is di- vided into four classes: Crustacea (Crabs, lobsters, shrimps, crawfish, and sow-bugs [Oniscidce]). — Of this class only the sow-bugs or pill-bugs are apt to be confused with insects, and are of some economic importance, though not so injurious as many suppose. A common injurious species is shown in figure 5. Arachnida (Scorpions, daddy long-legs, spiders, mites, etc.) . — The scorpions are well known in the South and need no de- scription. The same is true of the daddy long-legs or harvest- men, and spiders are everywhere. Among the mites, however, we have one species, the so-called red spider, which is quite in- jurious at times and which as it is commonly supposed to be an insect we will treat in one of the following chapters. Fig. 5.— Water-cress sowbug (Man- casellus brachyurus). Enlarged. (After Richardson.) VALUE OF A KNOWLEDGE OF ENTOMOLOGY 5 Myriopoda (Thousand-legged worms). — These creatures are known to most persons, and are divided into two orders: The Centipedes constitute a group in which each segment bears only a single pair of legs, while the body is generally flattened, and the antennae are long with many joints. They live mostly by preying upon other insects. The Millipedes (fig. 6) have two Fig. 6.— Myriopod. Enlarged pairs of legs to each segment except the first three; the body is more or less cylindrical, and the antennae are shorter with few joints. Most species feed upon decomposing vegetable matter, but some attack growing plants, more particularly those of the garden and greenhouse. Injury by these creatures, how- ever, is frequently exaggerated, as in the case of the sow- bugs, previously mentioned. Hexapoda (Insects). — This brings us to the true insects which are distinguished from the other three classes that have been mentioned by having the body divided into three distinct portions, — head, thorax (chest), and abdomen (belly) (fig. 7). They have a single pair of an- tennae or feelers, normally three pairs of legs, and in the mature stage, one or two pairs of wings (save in exceptional cases). In , , ,. Fig. l.—Polistes bellicosus. Somewhat our present advanced state of enlarged . (Marx del, u. S. De P t. Agr.) knowledge of the classification of true insects they have been divided into no less than nine- teen 1 orders, but for present purposes what is known as the 1 For a list of these orders the reader is referred to pp. 77-81 of Comstock's Manual for the Study of Insects, Comstock Publishing Co., Ithaca, N. Y. 6 INSECTS INJURIOUS TO VEGETABLES old Linnsean classification will suffice. This embraces seven orders, — Coleoptera, Orthoptera, Lepidoptera, Hymenoptera, Neuroptera, Diptera, and Hemiptera. The first six of these orders are mandibulate or chewing insects, at least in the most active stage of the insect, while the last are haustellate or sucking insects. This is important to know as on this classifica- tion depends the question as to whether stomach poisons, such as the arsenicals, or contact poisons, such as kerosene and its different preparations, are best suited for their destruction. ORDERS OF INSECTS Coleoptera or Beetles. — Beetles are distinguished by having a pair of more or less horny elytra or wing-covers which nor- Fig. 8.— Convergent ladybird (Hippodamia convergens) . a Adult; b, pupa, c, larva. All much enlarged. (Author s illustration, U. S. Dept Agr ) mally meet in a straight line down the back. Beneath them are the true membranous wings, usually folded. The mouth- parts of beetles and their larvae (the latter usually called grubs) are formed for biting. A common beetle, a beneficial ladybird, is shown in figure 8, in different stages. Many species of beetles are injurious both in the adult and larval stages.. Among the best known forms of this order that injuriously VALUE OF A KNOWLEDGE OF ENTOMOLOGY 7 affect vegetables are wireworms, white grubs and their parents the May and June beetles, leaf-beetles, flea-beetles, pea and bean weevils, blister beetles, bill-bugs and other snout-beetles. Lepidoptera (Butterflies and moths). — This order consists of insects having four membranous wings covered with more or less minute overlapping scales. The mouth-parts of the adults are formed for sucking, but the larvae (called eater- Fig. 9.— Cabbage looper (Autographa brassicse). a, Male moth: b, egg; c, caterpillar; d, pupa in cocoon, a, c, d. One-third larger than natural; b, more enlarged, (a, c, d, after Howard; b, Chittenden, U. S. Dept. Agr.) pillars, "worms," etc.) have well-developed chewing mouths. The Lepidoptera are of about equal importance with the Coleoptera or beetles as pests. Examples of noxious forms that are destructive to vegetable crops are found in the cutworms, army worms, webworms, cabbage and tomato worms and various caterpillars. The cab- bage looper is shown in figure 9 in its four principal stages. 8 INSECTS INJURIOUS TO VEGETABLES Hymenoptera {Saw flies, ants, wasps, bees, etc.). — In this order there are two pairs of membranous wings with comparatively few veins, the hind-wings being the smaller pair. The mouth- parts of the adults are formed for both biting and sucking, and those of the larvae, which are injurious, for biting. The females are furnished with stings, piercers or saws. In this order there are comparatively few noxious forms, and most of these are confined to the sawflies whose larvae, known as slugs and false-worms, consume vegetation, doing injury similar Fig. 1 0.— Screw-worm (Compsomyia macellaria). a. Maggot; b, head of same; c, anal segment from rear; d, puparium; e, adult fly;/, head from side. All enlarged. to that accomplished by caterpillars. Some species of ants are troublesome, both directly and indirectly, in the latter case by acting as carriers of aphides or plant-lice, scales, and some other insects. This order, however, contains many bene- ficial forms, such as ichneumon and chalcis flies — parasites of noxious insects, and wasps which also destroy insect pests. One of these is shown in figure 7. Diptera, or Flies. — Insects of this order have a single pair of wings which are borne on the mesothorax or middle por- tion of the thorax. The metathorax or hind portion bears a pair of knobbed thread-like processes called halteres, poisers, or balancers. The mouth-parts are formed for sucking in the adult condition, but in the larvae (called maggots) the mouth- VALUE OF A KNOWLEDGE OF ENTOMOLOGY parts are for biting. To the Diptera belong such pernicious insects as mosquitoes, house and horse flies, and root-maggots. For illustrations of the Diptera, see figures io«and 20. Orthoptera (Grasshoppers, crickets, roaches, katydids, etc.). — In this order the insects have two pairs of wings, — the first somewhat horny and overlapping when at rest, the second pair thin and folded when at rest in plaits like a fan. The metamorphosis is incomplete, and all forms of the insect (ex- cept the egg) are active, with biting mouth-parts. The Rocky Mountain locust is an example of this order (figs, n and 12). Hemiptera. — This order divides into three suborders, — the Heteroptera or true bugs, the Homoptera containing aphides, leafhoppers, etc., and the Physopoda or thrips. These groups have in common four wings, the mouth-parts in all stages ss?4ifeL JFBC — formed for sucking, with in- complete metamorphoses. Fig. 11. — Rocky Mountain locust (Melanoplus spretus). a, a, Newly- hatched nymph; b, full-grown nymph; c, pupa, natural size. (After Riley.) Fig. 1 2.— Rocky Mountain locust (Melan- oplus spretus). Adult. Natural size. (After Riley.) Suborder Heteroptera. — In the true bugs the anterior wings are thickened at the base and thinner at the extremities and overlap on the back, and the beak arises from the anterior portion of the head. It includes various forms of noxious insects, such as the chinch bug, numerous plant-bugs, (fig. 13), squash bug, and certain beneficial species, such as soldier-bugs. Suborder Homoptera. — In this group the wings are of uni- form thickness and usually slope at the sides of the body, the beak arising from the hinder portion of the lower side of the head. In this suborder most injurious pests are found in the aphides (fig. 14), leaf-hoppers and the like. 10 INSECTS INJURIOUS TO VEGETABLES Suborder Physopoda. — The thrips have two pairs of wings of similar form — long, narrow, membranous, not folded, and Fig- 1 3.— Brown plant-bug (Euschfstus variolarius) . Adult at right; last riymph stage at left. Enlarged. (Howard, U. S. Dept. Agr.) with few or no veins. These are fringed with long hairs and do not fold, but are laid horizontally along the back when at rest 1 (fig. 15). Neuroptera. — This order has been subdivided by re- cent writers into numerous other orders, but as they are of comparatively little if any economic importance, these Fig. 15.— Enthrips tritici. a, Adult thrips; b, antenna; c, leg. All highly magnified. Fig. 14 -An aphis. Much enlarged (Aftgr Hubbard) u# S . Dept . Agr .) subdivisions need not be discussed here. The Neuroptera, in fact, have served as a "catch-all" for the groups that could not 1 According to recent classification the Physopoda constitute a, distinct order, but the Parasitica, which includes the parasites of man and other mammals, is a suborder of equal rank with the Heteroptera and Homoptera. VALUE OF A KNOWLEDGE OF ENTOMOLOGY II be classified with other orders. Among neuropteroid insects of interest to the farmer are the aphis lions or young of the lace- winged flies (fig. 16) which are beneficial by feeding on noxious insects and the dragon flies, which also do some good in destroying injurious forms. The Coleoptera, Lepidop- tera, Hymenoptera, Neurop- tera and Diptera have what is termed a complete metamor- phosis, which means that they undergo four totally different stages, of egg, larva, pupa and adult or imago. In the remaining Fig. 1 6.— A lace-wing with eggs at right Fig. 1 7- —Tarnished plant-bug; four stages of nymphs. Enlarged (After Forbes) two orders, Orthoptera and Hemiptera, the metamorphosis is incomplete, which means that in the stages between the egg and the imago the insect undergoes only a gradual change, each successive substage (nymph) after the first being very like the one that precedes or follows it (fig. 17). NATURAL ELEMENTS IN THE CONTROL OF INSECTS The benefits which the agriculturist reaps from the friendly assistance of various forms of insects which prey upon nox- ious forms is very considerable. Every tiller of the soil 12 INSECTS INJURIOUS TO VEGETABLES should recognize their usefulness, but some are prone to ex- pect too much from them in the subjugation of farm pests, and opinions are so diverse that the grower is sometimes in doubt as to whether the insects which are indicated as his allies are not, in reality, pests. A little study is necessary in many cases to discriminate between noxious and innoxious species and those which are truly and exclusively beneficial. Organisms beneficial to agriculture may be variously classi- fied, but fall naturally into four groups. The most important Fig. 18. — Fiery ground-beetle, a, Larva; b, beetle. (From Riley) a Fig. 19. —A soldier-bug {Milyas cinctus). (Riley, U. S. Dept. Agr.) forms are: (i) predaceous insects, consisting of those which feed externally upon their prey; (2) predatory animals other than insects, such as birds and mammals; (3) parasitic insects which live in the bodies of their hosts; (4) fungi and diseases of bacterial origin. The weather has quite as great effect in the control of in- sects as in the yield of the crops themselves. Extremes of heat or cold, excess of moisture or dryness have the same effect on insect as on plant life. The results of severe rainstorms, sudden cold snaps and prolonged drought on many insect pests are well known. Of predaceous insects the most useful are undoubtedly the VALUE OF A KNOWLEDGE OF ENTOMOLOGY 1 3 ladybirds 1 (fig. 9), from their destruction of aphides alone, although some forms also do as good if not even better work in limiting the numbers of scale insects. Ladybirds also devour the eggs and larvae of various other insects, and especially of soft-bodied forms. Several ground-beetles (fig. 18) live at the expense of cutworms and other vegetable-feeding caterpillars and the larvae of beetles. Of this number the great Lebia 2 follows the Colorado beetle wherever it goes, and appears to Fig. 20.— Syrphus-fly (Syrphus ribesii). a. Fly; b, lateral view of head; c. larva or active immature form. All much enlarged. (Author's illustra- tion, U. S. Dept Agr.) have a very considerable effect in limiting its overproduction. Soldier-bugs 8 (fig. 19) of several species attack and kill soft larvae of beetles and of moths. Other important predatory enemies of noxious insects are syrphus and robber flies, spiders, and daddy long-legs or harvestmen. The syrphus flies 4 (fig. 20) are particularly useful in destroying aphides. Wasps of many forms provision their nests with the larvae of beetles and of moths, and certain species of mites help in reducing insects of pestiferous habits. 1 Coccinellidse. 2 Lebia grandis. s Podisus spp. * Syrphidae. 14 INSECTS INJURIOUS TO VEGETABLES Several kinds of birds, as also mammals, amphibians, and reptiles, are well-known enemies of noxious insects, and domes- tic fowls are of considerable value as destroyers of larvae, especially such as are not hairy, like the "slugs" of asparagus and potato beetles. Among beneficial birds, quail are important enemies of such pests as the potato beetle and boll weevil. Mammals include skunks, which kill great numbers of May beetles. Toads of the amphibians are particularly useful as insect destroyers. Chickens, ducks and turkeys are all used in a practical way by farmers for disposing of a variety of insects. Turkeys ap- pear to be naturally adapted as substitutes for "hand-picking" tomato or tobacco worms and are actually employed and loaned for such purposes, and swine Fig. 21 . — Pteromalus puparum, Male, are equally fitted for the destruc- Highly magnified. (Author's illustra- . r , . , , , tion, u. s. Dept. Agr.) tlon of white grubs and other subterranean pests. The parasitic enemies of noxious insects are legion, but their activity as useful allies to the farmer is to a large extent dependent on atmospheric conditions. As a general rule also they seldom appear in their greatest numbers until their injurious hosts have done more or less damage. Their principal useful- ness, then, is in so decimitating the numbers of noxious species in one season that few are left to prey upon crops the following year. The principal useful parasites belong to the family Hymenop- tera, four-winged creatures of wasp-like appearance and variable size. ■ Of these are the ichneumon flies, 1 chalcis flies, 2 bra- conids, 3 the egg parasites 4 and some others. 1 Ichneumonidse. . ? Chalcidoidea. 3 Braconidee. * Proctotrypidse. VALUE OF A KNOWLEDGE OF ENTOMOLOGY 15 An excellent example of the value of parasites as insect destroyers is afforded by the imported cabbage worm. One of its parasites, Pteromalus puparum (fig. 21), destroys in some seasons from 80 to 90 per cent, of these "worms." Another parasite, Apanteles glomeratus was purposely introduced by the United States government about 1883. During the autumn of 1904 this species held its host under complete control in the District of Columbia, killing every "worm" which came under the writer's observation. This species is shown in figure 2ix. Fig. 2lx— Apanteles glomeratus. a, Adult fly; b, cocoon ;.c, flies escaping from cocoons a, b, Highly magnified c, natural size. (Author's illustration, U. S. Dept. Agr.) CHAPTER II PREVENTION BY FARMING METHODS Having shown in a general manner what is desirable for the best understanding of the subject under consideration, it is next in order to point out how this knowledge may be utilized in the prevention or mitigation of injury. A knowledge of the origin and distribution of insects enables us to judge of the probable and ultimate spread of introductions from abroad and from one portion of our country to another. Thus we can predict, with a considerable degree of certainty, that certain species will not be injurious beyond certain bound- aries, and that others will widen their range beyond known limits. Knowing the effects of atmospheric conditions, of heat and cold, dryness and humidity upon insect reproduction, we can be forewarned of injury and can plan accordingly. Experience having taught that the clearing of uncultivated or neglected land is almost certain to be followed by depredations of insects which had inhabited the wild plants and weeds, we are enabled to plant such crops as will be least affected by these insects. Knowing what insects are controlled by predaceous, parasitic and other enemies, such as beneficial insects, contagious diseases, wild and domestic animals, we can in many cases, untilize these natural agencies in our warfare against them. Most of the different farming methods which A*ili be con- sidered are of use in combatting insect enemies of cereals; in short, without their employment it is impossible to avoid losses from these insects, as it is seldom practicable to use insecticides on growing grain. The usefulness of many of these methods is due to the slow spread of many species except at more or 16 PREVENTION BY FARMING METHODS 1J less regular periods of migration and the strong tendency which many have of depositing their eggs in the same field where they have bred or hibernated. The value of these methods in the treatment of the Hessian fly is summed up by Prof. F. M. Webster in the statement that "four-fifths of its injuries may be prevented by a better system of agriculture." SELECTION OF PLACE AND TIME FOR PLANTING With a knowledge of the insects which attain their highest development in sandy locations, in marsh land or in the neighbor- hood of woodland, we can prepare for attack from them after the ground has been cleared for planting. Much depends upon a judicious selection of the crop to replace weeds or to be grown in forest clearings or in land that has long laid waste. Unfortu- nately the crops frequently selected for planting in new land are the very ones most subject to attack, and if farmers generally are to preserve their crops from insect injury they must employ new tactics. Corn and other cereals, potatoes and strawberries are crops especially attractive to insects which have developed in unused land. They should therefore not be planted in new land until after some less susceptible plant be used as a first crop. Buckwheat and clover are less likely to be injured. Corn should not as a rule be planted in marshy tracts or in reclaimed river beds owing to the danger of injury from bill-bugs, root-worms, wireworms and the like. Nor should corn follow wild grasses, which are liable to be affected by the same classes of insects as well as cutworms and white grubs. Next in order is the choice of the proper time to plant to avoid insects which are liable to' attack the crops which we in- tend to grow. With early and late planting must be combined occasional planting between two generations of an insect, and the timely disposal of the crop, particularly if this is damageable. l8 INSECTS INJURIOUS TO VEGETABLES Late planting is practiced against numerous insects with ex- cellent success, the object being to have the crop appear after the disappearance or dispersion of the insect whose ravages are feared. It is, in fact, a standard remedy against some insects. THE MAINTENANCE OF VIGOROUS GROWTH If plants be weakened through atmospheric or other cause or through a combination of unfavorable conditions they are as a general rule more subject to injury by insects, but there are many crop plants, as for example certain varieties of wheat, that the ranker the growth the more they are subject to infestation by such insects as the Hessian fly. Some have claimed that weak plants only are subject to injury, and that plants might be grown by artificial methods for the production of such great vigor that insects would not seriously damage them. Although this might be possible with a limited number of plants, we can not now procure all of the most favor- able conditions. As an instance, we have only to cite the re- ported successful use of kainit and nitrate of soda as a remedy for wireworms and some other insects in New Jersey, and their failure when applied in other states. Possibly soil and atmos- pheric conditions have in some instances had some bearing upon these failures. Most failures, however, are due to wrong methods. BURNING OVER FIELDS AND WASTE LANDS A farm practice in favor in many regions against cereal-feed- ing insects consists in burning over fields after harvest or be- fore plowing. It affects particularly such insects as hibernate on or just below the ground. Among well-known pests that can be reached by this method are cutworms, many of which live all winter long above the earth's surface partially grown, also webworms, grasshoppers, aphides and plant-bugs, and some forms of beetles and other insects which hibernate in the adult stage at or near the surface. PREVENTION BY FARMING METHODS I9 CROP ROTATION One of the best of farming methods is crop rotation, as it serves several purposes. If pursued on scientific principles it is not only a benefit to the land, but is one of the easiest means of preventing attack from insects, fungous and other diseases, and weeds. In a general way it may be said that crops of like kind, that is, belonging to the same botanical groups, and much sub- ject to insect attack, should not be planted in successive years in the same fields. Thus it is inadvisable, to plant corn in old wheat fields, and it is equally unwise to grow small grains after corn. Where insects occur like the bollworm, which attacks several plants, injuring tomato fruit, corn ears, bean pods, etc., in similar manner, still greater care is necessary in selecting the land for planting. It follows that it is bad practice to plant corn after tomatoes or tomatoes after corn, or to plant either of these crops in or near cotton fields. Here is where a knowledge of botany sufficient to enable the grower to know the botanical families to which his crops, as well as the weeds, belong becomes of value; since with the ex- ception of insects known as general feeders, most species feed by preference on one or more plants of the same botanical group. Thus an insect destructive to cabbage will attack any cole crop, such as turnip or radish, and weeds such as wild mustard and pepper-grass ; hence care should be used not to plant cabbage in fields in which the other plants have grown. The same rule holds with plants of the cucumber kind. Melons should not follow squashes, nor pumpkins cucumbers. Rotation of crops is prac- tically the only means of dealing with some of the most im- portant insects, among which are the western corn root-worm. Where diversified farming is practiced, such leguminous plants as crimson clover and cowpea are most useful as alternates, be- cause valuable as soil restorers, and not as a rule subject to serious insect injury. 20 INSECTS INJURIOUS TO VEGETABLES DIVERSIFIED AGRICULTURE Entire plantings are frequently failures because growers rely on single, or, at best, two or three crops for a livelihood. The practice of growing large areas to cotton in the South is an ex- ample. Occasionally this is varied by corn or tobacco, and all three crops are likely to be injured by the same insects, e. g., by the bollworm, corn-ear worm or tobacco budworm, as this one species is variously termed. In Texas there was at one time the threatened danger of an abandonment of cotton culture owing to the rapacity of the boll weevil. The large appropria- tions that have been made available by Congress for the con- trol of this pest should result in materially reducing the losses occasioned by it, which now bids fair to seriously hamper the production of this staple which nets our country $500,000,000 or more annually. The melon or cotton aphis has done great damage in Texas since the beginning of the new century and various crops in the South are threatened with new pests. It is quite a problem, therefore, to decide what may be grown most advantageously. Other striking illustrations of the danger of cultivating a single crop can be pointed out. In some years in the past it was simply impossible for truckers in parts of Maryland and Virginia to make a living from cabbage, or other cruciferous crops or from melons and other cucurbits, but by growing several crops of widely different kinds they make a profit. In the Northeast the farmer does not have such problems with which to contend and yet raises many crops, keeping his hands busy nearly the year round, and there is no excuse for growers in the South and elsewhere cultivating only a few crops when by diversified or general farming losses from insects, from plant diseases, and from adverse climatic conditions could be avoided/ PREVENTION BY FARMING METHODS 21 FALL PLOWING AND CULTIVATING One of the best methods of deterring insects from injurious attack, comparable with clean culture, burning over, submersion and the like, is fall plowing and other ways of cultivating. The process may be varied by harrowing, disking, and raking, and sometimes in cases of serious infestation a cross-plowing is advisable. The object of fall plowing is to bring the insects that are feared to the surface where they will be exposed to cold and other elements and to natural enemies such as domestic and wild birds and mammals. This method is particularly valuable to prevent the recurrence of severe attacks and is beneficial for most forms of insects which hibernate under or near the surface of open fields, meadows and like places. It is particularly indi- cated for many insects affecting cereals, cucurbits and some other vegetables, and where corn and other crops subject to injury by white grubs, root-worms and wireworms and other subterranean insects, as well as cutworms, grasshoppers and others, are to be planted in sod or weedy land. Where the forms of insects mentioned are extremely troublesome, the land should be very thoroughly broken, and the insects, whether larvae, pupae, or adults, should be as much exposed as possible. This remedy is very effective in cold climates since the exposed insects are unable to obtain secure shelter before severe frosts. Fall plowing should be practiced for most crops where it does not interfere with other methods of cultivation. The numbers of the squash-vine borer can be greatly reduced by lightly harrowing the surface of infested fields after harvest so as to bring the cocoons to the surface, and then plowing in the spring to a uniform depth of six inches or more, so that the adults will not be able to issue. Disking, or cultivation with a disk harrow, is particularly recommended against the fall army worm, which hibernates as pupa near the soil surface. A somewhat similar method of 22 INSECTS INJURIOUS TO VEGETABLES treating lawns infested by army worms, and root webworms, consists in going over them thoroughly with a long-toothed steel rake. CLEAN FARMING METHODS The most valuable of all methods of controlling destructive insects, if we except the employment of insecticides, consists in the observance of clean cultural practice, and when with this we combine the judicious use of other methods, including me- chanical ones, only moderate use of poisons, employed at the proper time, is necessary. It is a more or less complete safe- guard against the bulk of insects that ravage our crops. Clean farming should always be practiced in the growing of crops that are liable to severe insect injury. Where the char- acter of a crop will permit, still more can be accomplished by using portions of the same or a similar crop as baits. In ad- dition, it is also desirable to employ as trap crops such weeds as the insects normally affect and which already grow in the fields, while in many cases it has been found of value to plant weeds or other crop plants to lure the insects from the main crop. Clean methods of management, though indicated as protective against most insects, is a practical necessity where there are many species that injure fall crops, such as cabbage, turnip and other crucifers, and for such insects as pass the winter in rub- bish in the fields that they have ravaged. FARM INSPECTION An old proverb, "An ounce of prevention is worth a pound of cure," is as applicable to man in relation to insects which injure his crops as to other matters which affect his well-being. Eter- nal vigilance is also the price of a good crop. The fact that the greatesL injury due to such insects as army worms, cut- worms, blister beetles and the like is accomplished before their presence is known, indicates the value of prompt action in the treatment of the crops affected. Too frequently attack is un- PREVENTION BY FARMING METHODS 2$ noticed until damage is beyond repair, and this might be averted if the grower would only employ some simple farm practice like fall plowing. Promptness cannot be too strongly urged, for the application of remedies if too long deferred may be useless. As soon as a crop is planted it should be inspected every few days for signs of injury. If plants growing under the same conditions make unequal growth, over a considerable area, the backward plants should be examined for evidence of insect work. Insect injury is manifested in different ways, as has already been described in the Introductory Chapter (page x). After crops have made some growth, a weekly inspection will in ordinary cases suffice until the danger point has passed; and as attack usually begins on the borders of a field, by walking around it most forms of insect injury may be detected. Pre- ventive work, such as clean culture, rotation and fall plowing, should be instituted as a part of the routine of farming; and if systematically pursued losses through insect ravages will be reduced to a minimum; while prompt action at the very outset of attack, in the application of insecticides or mechanical methods will, in exceptional cases, save the crop. COOPERATION IN THE CONTROL OF INSECTS The grower who institutes practical methods for the control of insects which menace his crops has a distinct advantage over one who does not. The enterprising farmer is enabled to ob- tain a good yield while the careless grower stands a chance of a money loss on his crop. It has long been recognized that insects of many forms are a direct benefit to the progressive man, who farms on scientific principles, enabling him to pre- serve his crops while the damage that may be done to his more careless neighbors enhances the market value of what the scientific farmer raises. This is a decidedly narrow-minded and selfish way of looking at the subject. 24 INSECTS INJURIOUS TO VEGETABLES Large corporations like seedsmen, canners, and picklers, plant very extensive areas and employ others in growing the same crops. Such firms provide seed and machinery, and keep posted on what will benefit not only their own interests, but those who labor for them. This applies to the means of controlling in- sects, including the purchase of insecticides and spraying ap- paratus, and by purchasing at wholesale they greatly reduce the cost for themselves and their co-laborers. The scope of this work might be extended (and perhaps is in use in some measure) to those who grow on a smaller scale, the farmers of a given locality having a community of interests pooling their interests for the purpose. Growers having small areas are often so little troubled with insects that it does not pay to buy expensive outfits; and insecticides cost at retail frequently two or three times as much as when purchased in quantity. For example, bisulphid of carbon, a standard remedy for the melon aphis, bean and pea weevils and root-maggots, costs only 10 cents a pound in fifty-pound lots, and from 20 to 30 cents when bought in smaller quantity. This difference could be saved by the co- operation of several neighbors, and it could be extended to the purchase of expensive spraying outfits. Co-operation is of especial value in the control of insects such as the squash bug, cucumber beetle, harlequin cabbage bug, and cabbage looper, that cannot be held in subjection by ordinary poisons. If growers who suffer most could induce neighboring farmers to employ clean farming methods and crop rotation, the ravages of these pests would be greatly reduced. The harlequin cabbage bug is quite resistant to poisons, and since about the year 1900 it has been so nearly exterminated in its northern range, that if farmers would work together when it again makes its appearance northward and use trap crops over large areas, for example over townships, the insect might be prevented for several more years from regaining its lost foothold. This, with clean methods of cultivation, would leave little else neces- PREVENTION BY FARMING METHODS 25 sary to keep the insect down, unless by carelessness it were permitted to return unmolested to its old haunts. Immeasurable benefits would undoubtedly accrue by the subordination of self- interest for the common weal. Indeed this subordination is only apparent and it has been pointed out that one of the best, as it is the noblest, methods of self-help consists in helping our fellow men. Fig. 2\y. — A simple coal-tar pan to be drawn by hand (After Riley) CHAPTER III MECHANICAL METHODS OF DESTROYING INSECTS OR PREVENTING INJURY Many valuable mechanical methods of controlling insects are employed, such as hand-picking, ''bugging" or beating, collecting in nets or in hopper-dozers, ditching, disking, driving and others. Hand-picking is useful for large conspicuous inactive insects, such as the squash bug, potato beetle, cutworms and similar caterpillars. It is one of the simplest measures that can be em- ployed, and is valuable where other means cannot be used and where labor is cheap. Bugging. — This term is often used for jarring and beating in- sects from low plants into pans containing water and a thin scum of kerosene. The water prevents the insect from es- caping, and the floating kerosene kills every insect which comes in contact with it. Collecting in nets. — Hand nets of muslin or cheese-cloth such as school children employ for the capture of butterflies, are use- ful against some insects which affect truck crops. Among such are the tarnished plant-bug, which affects about equally vege- tables and small fruits. By sweeping over the plants to be protected and the weeds and grasses of the vicinity, thousands can be captured in a short time, and they can then be killed by throwing them into a fire or into hot water. Collecting in hopper-dozers. — Many forms of these death-deal- ing devices are in use for grasshoppers (see figs. 213; and 2iz) and for leaf-hoppers, which will be described in the discussion of those insects. 26 MECHANICAL METHODS OF DESTROYING INSECTS 2? Brushing methods. — Different methods of brushing more or less sluggish insects from their cultivated food plants have been in vogue for many years. Potato beetles and their larvae may be brushed from potato plants by means of a short-handled broom, a second person to follow dragging by horse power a bundle of brush or a harrow to crush the insects and bury them. This process is simplified in the treatment of the asparagus Fig. 21]2 INSECTS INJURIOUS TO VEGETABLES the grasshoppers can be controlled by several artificial methods. The remedies that have proved most efficient are plowing under the eggs before these have had time to hatch, and the capture by means of hopper-dozers of the unfledged locusts, as well as many of those which have become winged. These are shallow sheet-iron pans in which are placed tar or coal-oil tar or kero- sene oil, and which maybe drawn or pushed by hand over the ground or by horses, in such a manner that the hoppers will leap into the pans and be killed by coming into contact with the tar or oil. Hopper-dozers are shown in figures 213; and 2i#. Other remedies of great value in the prevention of injury to our cultivated crops are the bran-arsenic mixture and poisoned horse droppings. Directions for preparing the former have been given on page 54. Poisoned horse droppings consist of 1 part of Paris green mixed thoroughly in 60 parts of fresh horse droppings, 2 pounds of salt to half a barrel of mixture being added after being dis- solved in water. This is placed in half barrels and drawn on carts to the edge of the infested field or one likely to be invaded. The mixture is then scattered broadcast along the edge of the crop, or wherever needed, by means of a trowel or wooden paddle. The locusts are attracted to it and are killed in large numbers by eating the poison. Although this mixture is "sure death," it sometimes requires from two to five days for it to kill the locusts. Turkeys are of great value in freeing orchards and vine- yards of locusts, and they may be employed in other fields for the same purpose. In one case a flock of 766 turkeys were kept at work in the destruction of grasshoppers. The turkeys have to be watched, as they sometimes vary their diet with vegetables. In some cases it has been possible to ascertain the particular breeding places of grasshoppers, some species depositing their eggs in pasture lands and among foothills at the bases of mountains in the Far West, in regions in which the tar weed GENERAL CROP PESTS 73 grows. Here the eggs can be destroyed by burning over the ground late in the fall after all of the eggs are deposited, or by plowing them in to a depth of six or eight inches before they hatch in the spring. In case it is for any reason not feasible to employ any of these last mentioned remedies, and the place of egg deposit is ascertained, a watch should be kept for the young grasshoppers, and they should be destroyed as soon as possible after hatching by means of bran-arsenic mash. Cooperation is greatly desirable in the treatment of grass- hoppers, particularly in regions where they reach their greatest development; and the thoroughness with which work is done in one year will show the next season in the greatly reduced numbers with which the farmers will have to deal. Remedies for grasshoppers in general are applicable to the migratory species, but the latter sometimes occur in such im- mense swarms that it is difficult to treat them. It is of the highest importance that whatever remedies are employed must be used at the very first onset and generally over considerable territory, as the insects fly from one field to another. WHITE GRUBS White grubs occupy a prominent position among the many insect foes to agriculture. There are several hundred distinct forms of these creatures, each representing a different species of the family Scarabaeidae. A considerable number are of prime importance economically, the remainder are less injurious or do not attack useful plants. The noxious forms subsist on roots and are very abundant under sod, and in similar locations. Of these a considerable majority of the typical white grubs belong to the genus Lachnosterna, of which nearly a hundred species are known. The parents of white grubs are known as May beetles or "May bugs" in the South and Middle states, and as June beetles 74 INSECTS INJURIOUS TO VEGETABLES or "J une bugs" in the North, from their occurrence in numbers in these months in these different regions. Injury is by no means confined to the white grubs, but can often be laid to the account of the beetles, but the latter are most destructive to shade and fruit trees. White grubs or "grub-worms," with wireworms and cutworms were the original inhabitants of the soil before the advent of civilized man. They lived in our open prairies when America was still a wilderness, and they continue to dwell in our grass lands, meadows, fields and gardens and repel all attempts toward their permanent removal. The farmer who imprudently plants corn or potatoes in fields that have long laid waste and become grown up with weeds and grasses, or where strawberries have been the previous season, does so at the risk of losing his crop. The problem of how to. destroy them and to protect the crops from their ravages is a subject requiring constant and scientific treatment. Injury appears to be most noticeable to corn, grasses, small grains, beets, potatoes and other root crops, and strawberries, but the roots of young shade, fruit and forest trees are also attacked. As with insects of similar habits, white grubs and May beetles are liable to considerable fluctuation of numbers in dif- ferent localities and years. This is most noticeable after crop rotation, particularly, as might be inferred from what has al- ready been said, where susceptible crops are planted in grass lands. Attack may commence from the time the plant sends out roots, and continue for a much longer time, as these insects pass two or three years from the egg until they reach the adult condition. When the larvae are present in great numbers at the roots, the plants soo« die and whole crops are ruined. In a general way white grubs may be described as large, soft white or yellowish grubs, with wrinkled bodies, sparsely covered with fine hairs, having yellowish or brownish heads with strong mandibles, three pairs of distinct legs on the fore part of the GENERAL CROP PESTS 75 body (the three thoracic segments) and the hinder portion of the body considerably thickened toward the end. The normal position of typical white grubs is curved, as shown in figure 42, e. They crawl on their sides, not on their backs as is the case with the non-injurious white grub of the June beetle. The parents of the injurious or typical white grubs (Lach- Fig. 42.— Arcuate May beetle, a, Beetle; b, pupa; c, egg; d, newly-hatched larva; e, mature larva; /, anal segment of same. (Author's illustration, U. S. Dept. Agr.) nostema spp.) are for the most part large, shining brown beetles, known to every one from their habit of flying into lighted rooms through open windows, in late spring and early summer, buzzing and bumping upon the ceilings and walls and finally falling to the floor. A comparatively small number are yel- lowish, or plum color, and some few are nearly black. From April to July, according to climate, these beetles appear, often in great numbers, about our electric lights and upon our fruit and shade trees, their appearance each day beginning al- most uniformly at sundown. They feed voraciously upon the leaves of trees, and bushes such as blackberry, but are especially fond of the foliage of nursery stock and other young trees, particularly oak, chestnut, hickory, maple, and fruit trees, often doing such damage to newly transplanted shade and orchard trees as to result in their complete defoliation and destruction. The beetles fly and feed only at night, and during the day remain perfectly quiet in the vicinity of their feeding places. It has lately been shown conclusively (what was previously in- 76 INSECTS INJURIOUS TO VEGETABLES ferred by deduction) that one species, Lachnostema arcuata, 1 requires only a little over two years for larval development, but about three years are consumed from the time the egg is laid until the appearance of the beetle above the ground, and this is probably true of most of the species which occur in this country. Thirteen days was ascertained as the egg period, twenty-three for the pupa, and the total period from egg to adult required two years and fifty-one days. The sexes pair soon after their first appearance and the females enter the earth for oviposition. The eggs, which are rather large and whitish or gray, are deposited singly in the ground. The grubs, hatching among the roots of grass and similar plants, feed at first upon the tender rootlets and after- ward on the larger roots, and slowly increase in size until mature. The species which have been observed usually transform to pupae from the middle of June to September of the second or third year after hatching, and become fully-developed beetles in August or September of the same year. They remain in the earthen cells in which transformation has taken place, some- times at a depth of from twelve to eighteen inches, where they are protected from cold and frost, and appear abroad the fol- lowing spring to repeat the life cycle. Hibernation may occur in two stages of the larva, and occasionally in a third, and as beetles. The Arcuate May Beetle {Lachnostema arcuata Sm.) is the common May beetle of the Middle Atlantic region. The North- ern June Beetle (Lachnostera fusca Frohl.) is abundant in the Middle Atlantic region, and is quite as destructive and over a wider extent of territory. It is the common species from New England to Illinois, and occurs, but comparatively rarely, farther west. A large proportion of the injury caused by white grubs and June beetles in the region specified are due to this insect. 1 See article by the writer, Bui. No. 19, Div. Ent., U. S. Dept. Agr., pp. 74-80. GENERAL CROP PESTS J J The winged Northern forms of May beetles are replaced in Texas and some other portions of the South by three common species, two wingless (Lachnosterna cribrosa Lee. [fig. 43] and L. lanceolata Say) and one with similar habits (L. farcta Lee.) which do great damage in their beetle stage to trucking industries. They subsist largely upon weeds, hence in addition to treating af- fected plants with arsenicals, the weeds should be similarly treated. Late fall or winter plowing and avoidance of weedy fields for planting are advisable as pre- ventives. Swine should be used for de- stroying them and on small areas hand- picking can be employed, when the beetles Fig . ^,- Lachnosterna crib . make their appearance an hour or more rosa - Female. (Sander- , r , son, U. S. Dept. Agr.) before sundown. Among white grubs that are likely to be mistaken for the more injurious forms {Lachnosterna spp.) are the carrot beetle, which will be considered in a later chapter; the "muck worm," which occurs in manure and in the droppings of cattle, and which appears to be normally a purely dung-feeding species; the sugar-cane beetle; the rice grub; the green June beetle, and the brown fruit-chafer, which last will be described in the consideration of insects affecting sweet corn. PKEDACEOUS AND PARASITIC ENEMIES Although white grubs are apparently protected by their sub- terranean mode of existence and their life, as beetles, is com- paratively brief, many predatory animals as well as parasitic and predaceous insects attack and destroy them. Birds of sev- eral species and most wild mammals which still linger in cul- tivated regions are among this number. Domestic fowls are very fond of white grubs and, when given the opportunity, fol- 78 INSECTS INJURIOUS TO VEGETABLES low the plow for them. Swine also search out and eat many which they obtain by uprooting the turf. Of the insect enemies of white grubs are Tachina flies, wasps Fig. AA.—Tiphia inornata- Parasite of white grub, a, Female wasp; b, head of larva; c, larva from below; d, cocoon cut open. (After Riley) and parasitic Hymenoptera, mites, and predaceous ants.- Among these insects is the wasp, Tiphia inornata (fig. 44). Under certain conditions white grubs are also much subject to infec- tion by fungous parasites. REMEDIES FOR WHITE GRUBS Insecticides. — Good results have followed the use of bisulphid of carbon and kerosene emulsion against some species. The emulsion is diluted about ten times and poured on the ground about the infested plants. Application is made just before rain- fall, to insure the emulsion being washed deep into the soil so as to come into direct contact with the larvae. If rain does not fall within a day or two a copious watering should follow the application. Gas lime is also valuable. (See page 34.) Fall plowing is a most effective remedy. The land should be thoroughly broken, and loosened to expose the grubs and beetles to the elements during winter. This is particularly valuable in cold climates, as white grubs are unable to with- stand exposure to severe frost. Cross-plowing is sometimes advisable where there is severe infestation. This will insure the ground being often disturbed, and, if kept clean of weeds and other vegetation, the grubs can be "wiped out." Preventive measures are still more valuable. The best of GENERAL CROP PESTS 79 these consists in avoiding for the planting of vegetable crops land which is already known to contain white grubs and espe- cially grasslands, whether meadow or prairie. Corn fields should not be planted to root crops and the like without rotation with clover or other immune crops. Summer fallowing of infested land is said to be useful. Rotation of crops is valuable in connection with fall plowing. In case infested land is desired for the planting of corn, beets, potatoes, or other crop subject to severe injuries by white grubs, an application of fertilizer, such as nitrate of soda or kainit, put on as a heavy top dressing after the ground is prepared and before planting, has proved of benefit in some cases. Domestic animals. — Much good may be accomplished by en- couraging domestic fowls to follow in the furrows to pick up the grubs as they are turned up by the plow. Hogs are also exceedingly fond of white grubs, and if allowed the run of localities where these are abundant, after the crop is made, they will root up the ground and devour great numbers of them. WIREWORMS Of similar importance to white grubs as general farm pests are the wireworms. Though not related to the white grubs, they have very similar habits, the injurious vegetable-feeding forms being strictly subterranean and subsisting at the expense of various crops, especially corn, cereals, and grasses, but at- tacking, in the absence of these, various vegetables and other plants. The subject of soil and environment as regards attack by wireworms has not been thoroughly studied, but certain species are more numerous in sandy lands, and others are almost always found in unbroken prairies and in wild grasses. Thus it happens that, as in the case of white grubs, injury is most apt to occur when corn and other vegetables are planted in old sod, along the borders of marshes, in pastures and meadows. Nearly every tiller of the soil is familiar with wireworms, 8o INSECTS INJURIOUS TO VEGETABLES and there are many species, but, fortunately, a small percentage only of nearly 600 described forms have been identified in con- nection with losses. From an agricultural viewpoint they fall into two classes, such as feed upon living vegetation, and those which subsist upon rotten wood and similar material. Most of the noxious forms that have been recognized are wire-like, hence the common name, and are nearly cylindrical, hard, smooth and shining, and of a yellowish or reddish color. They have three pairs of legs placed far forward on the anterior extremity, and the last segment (the thir- teenth counting the head) ends in a proleg on the un- Fig. 45.— Wheat wireworm. a, Beetle; b, larva; c, anal segment of larva in profile. (Author's illustration, U. S. Dept. Agr.) Fig. 46. — Common click- beetle. Three times natural size. (After Forbes.) der surface. They are surprisingly hard in texture and among the most vigorous insects known, being difficult to poison by means of anything that has been tried. A common and destruc- tive species known as the wheat wireworm (Agriotes mancus Say) is illustrated by figure 45. GENERAL CROP PESTS 8l Wireworms are the offspring of snapping or click beetles or "snap-bugs," which are rather hard, pubescent creatures of elongate, oval form, and readily distinguishable from any other insects by the habit from which their common name has been derived, of vaulting into the air with a sudden click when they happen to fall upon their backs. The common click-beetle (Melanotics communis Gyll.) is shown in figure 46. Of the various vegetable crops attacked potatoes, according to record, are most injured, by having the surface of the tubers gnawed into and eroded by the worms." Turnips suffer similar injury, as do also to a less extent carrots, beets, cabbage, onions, lettuce, and others. In attacking growing plants wireworms usually devour the smaller roots or tender tubers, according to the plant affected, and in the case of attack on corn they fre- quently kill the plant by boring cylindrical channels through the under-ground portions of the stalk. The life histories and habits of wireworms vary according to species and climate, but in many respects they resemble the white grubs so closely that details may be omitted. The Cornell University experiment station carried on, through Messrs. Comstock and Slingerland, a valuable series of experi- ments against these pests extending over three years, with the result that none of the alleged standard remedies produced satisfactory effects. In short, the results were negative rather than positive, and no single method has yet been devised by which we can destroy these insects as we can most other pests. This is due to natural causes — viz., to the hardness and con- sequent hardiness of wireworms, two qualities which go hand in hand as regards insects and which render these creatures almost impervious to poisons that would destroy other insects, and to the fact that they live during nearly their entire active stage as wireworms usually rather deeply in the soil. They require two or three years, like the white grubs, for full matur- ity from egg to adult. 82 INSECTS INJURIOUS TO VEGETABLES METHODS OF CONTROL No application that can be made to the soil will kill the wire- worms without, at the same time, rendering the land unfit for cultivation for some time afterward. Most remedies, preventives, repellents and poisons that have been tried are hardly more than palliative. From among these the ones that give most promise are early fall plowing, the use of poisoned baits early in the season, with the selection of un- infested land for planting, and rotation of crops. We are in fact confronted with much the same problems as in the treat- ment of white grubs, only wireworms are even more difficult of suppression. Selection of land for planting. — The most important of de- fensive methods is the selection of the land for planting. It is inadvisable to plant crops peculiarly subject to wire worm attack, such as corn, potatoes, and other vegetables, as well as cereals in sod land or in unbroken prairie, and it is equally unwise to cultivate such crops in fields in which wireworms are known to be present. Fall plowing. — Infested or "suspicious" soil should first be prepared for the crop by plowing early in the fall. By this process the cells in which the pupae and hibernating adults are resting are broken up and the insects destroyed in great num- bers, so that fewer individuals survive to deposit eggs for an- other generation of wireworms the following year. Such as are not destroyed outright by this method will be more exposed to the elements and to predatory enemies. Crop rotation should also be practiced in the same manner as prescribed for white grubs. In addition to clover, buckwheat is said to be a valuable alternate because of the roots being too tough and hard to be injured, and possibly this is true of some forms of wireworms, but not of all, so we cannot place much reliance on this crop. If clover or other alternate be allowed to remain for one or two years after grass has been cut, veg- GENERAL CROP PESTS 83 etables subject to attack can then be planted with much less danger of serious infestation. It is difficult with our present knowledge to name an absolutely immune crop. Poisoned baits. — An efficacious remedy is found in poisoned baits. One of these consists in sowing corn, soaked in water, containing arsenic or strychnine, over the field about ten days before the crop is planted and then harrowing it in. The larvae that attack the poisoned kernels will be destroyed. For luring beetles, as well as larvae, baits of sliced potatoes or other veg- etables, or wads of succulent vegetation, such as clover, or pig- weed, or sweetened corn-meal dough, are useful. These are poisoned in the same manner as the corn and placed about the fields under boards early in the season. These traps should be renewed as often as possible. Experiments have shown the futility of starvation of wireworms by clean fallowing. Although these remedies are not infallible against wire- worms, they are of value in certain sorts of soils against some species, and they serve in a manner to destroy white grubs and cutworms which are also apt to be present. APHIDES, PLANT-BUGS AND RELATED INSECTS Nearly all forms of plants are attacked by sucking insects, the aphides, plant-bugs, leafhoppers and numerous related forms. The best known are the aphides or plant-lice, many of which do injury to vegetable crops. Among other insects which obtain nourishment by suction are several species of true bugs of the family Capsidae, generally termed plant-bugs, although some forms are also known as leaf-bugs, chinch bugs, and other names indicative of their habits or appearance. The commonest and most injurious of these insects to vegetables are two forms of false chinch bugs, the tarnished plant-bug and garden flea-hopper. The thrips also obtain their food by suc- tion, and for convenience may be included in the same category, although they are not closely related to them structurally. 84 INSECTS INJURIOUS TO VEGETABLES Aphides or Plant-lice. — Nearly every one knows the plant- lice or aphides, since there are few succulent plants that are exempt from their attack. Many staple crops of the field, garden, and orchard are very severely damaged when these insects multiply in unusual numbers, as so frequently happens. Aphides are also known as "lice," "aphis" and "green fly." There are many species, as varied in appearance as in habits, and although they have attracted attention for years on account of the injuries which they cause and their interesting habits, they are perhaps less understood than any large group of insects which could be named. In fact, we are not as yet able to estab- lish beyond a certain degree of doubt the identity of some of our most injurious forms and we know less of their life economy. Gardens are seldom free from their attacks, and cabbage and like crops, melons, cucumbers and similar plants, peas and young budding fruit trees suffer severely in some seasons. The best-known aphides are soft-bodied and green, very minute in size, with long legs and antennae. Immense masses of them frequently congregate on single plants, sometimes over- running entire fields. If a mass be closely examined it will be seen that many are wingless during the greater part of the season ; later, however, there are many which develop wings and are capable of flight. There are many stages of these in- sects, but the body is usually formed more or less like a pear, and the winged forms have two pairs of very delicate trans- parent wings with a few simple veins. The first and second pairs of wings are usually connected as in wasps and bees, by a hooklet. The haustellum or beak by which aphides obtain their food is three-jointed and of variable length. The eyes are compound and project prominently at the sides of the head. The aphides exude "honey-dew," a transparent fluid with a sweetish taste. Frequently it is excreted in such quantity that it forms a shining cover to the leaves of plants. The honey-dew of most species is very attractive to a number of GENERAL CROP PESTS 85 other insects — ants, wasps, bees and flies — and in the fond- ness of ants for this substance there is developed a curious inter-relationship. The various phases of development, the varieties of forms produced by some genera, in fact, the life economies of these Fig. 47-— Melon aphis, a. Winged female; oa, enlarged antenna of same; ab, dark female, side view: b, young nymph or larva c, last stage of nymph; d, wingless female — all greatly enlarged. (Author s illustration, U. S. Dept. Agr.) Fig. 48.— Flavescent leaf- hopper (Empoasca flaves- cens). Highly magnified. (Author's illustration, U.S. Dept. Agr.) insects would fill several volumes, and there is such great diversity of habit that it is difficult to generalize. The species which feed upon vegetable crops live for the most part on the under surface of leaves; but some are root- feeders, and the destructive grape phylloxera is an example of one of these subterranean forms which produce galls. The melon aphis (fig. 47) is one of our commonest and best known vegetable-feeding forms of this class. The best remedies for aphides are kerosene emulsion, fumiga- tion with bisulphid of carbon and with tobacco extracts, clean cultural methods of farming and the encouragement of natural enemies. These remedies are considered on pages 165 to 168. The Leafhoppers. — Leafhoppers are familiar to nearly everyone, although not everybody knows them by this name. 86 INSECTS INJURIOUS TO VEGETABLES As we walk over lawns and through meadows and pastures generally, particularly in midsummer and later, myriads of these minute creatures fly up and are sometimes annoying by getting into our faces and even our eyes. Recently their true economic value has been ascertained, and this was brought about mainly through the studies of Prof. Herbert Osborn, in Iowa. They are most numerous in grasses from which they drain the vitality by sucking the sap from the blades. It has been estimated that between one-fourth and one-half of all the grass growing annually is destroyed by leafhoppers, a startling statement but borne out by actual observation. Although most of these insects feed on grasses, there are some which, partic- ularly in their later stages as nymphs and as adults, attack various vegetables and other plants. Leafhoppers are mostly small, some very minute and slender, with short heads more or less crescent-shaped, and with long hind-legs which fit them for jumping. They also have long wings and are strong flyers. The species illustrated (fig. 48) attacks a variety of vegetables. In their attacks on plants the usual method is to puncture the cells from the under side of the leaves, causing yellowish, brownish or other discolored spots to appear later. When punctures are numerous entire leaves wilt and die. A few forms attack culinary vegetables by preference, but most others occur on different plants. No less than thirty distinct species have been found on beets. Methods of Control. — Several methods have been devised for keeping leafhoppers in subjection. The standard remedies are kerosene-soap emulsion and sprays of soap. An underspray- ing is always necessary. The spray should be as fine as possible, and applied upon the first appearance of the insects, not only to produce the best effect, but because by using it early in the spring the insects may be prevented from developing in large numbers later in the season, for with many forms there are two and sometimes three generations produced annually. GENERAL CROP PESTS 87 Leafhoppers may also be captured on sticky surfaces, and one good way of destroying them in small gardens is by causing them to fly up and capturing them on large frames coated with sticky substances such as coal tar. If this method is persisted in for several days few of the insects will be left, as they are readily caught. A good time for this work is just before sun- down. Special hopper-dozers are used for leafhoppers, similar to those described as grasshopper destroyers (page 71). Some of these are termed "hopperettes." The Tarnished Plant-bug (Lygus pratensis Linn.). — This bug Fig. 49 —Tarnished plant- bugr. Adult at left: last stage of nymph at right (Author's illustration, U. S. Dept. Agr.) is one of the most troublesome of its kind. It is found prac- tically everywhere in North America, and attacks many plants, cultivated and wild. It occurs throughout the warm season, and frequently does damage to vegetables and to trees grown in nurseries. The mature plant-bug (fig. 49) is of nearly elliptical form, and considerably flattened. The head is nearly triangular, with the eyes showing prominently at the sides. It is pale, obscure, grayish brown, marked with black and yellow, the thorax also with red. The length is about one-fifth of an inch. With little doubt this plant-bug has five stages of the nymphs to agree with related species which have been traced through their metamorphoses. The first stage measures only about one- SS INSECTS INJURIOUS TO VEGETABLES twentieth of an inch, and is yellowish green. This species is quite injurious to cabbage, turnip, potato and cucumber, and attacks also salsify and celery. The principal injury is ac- complished in the spring, by the adults piercing and sucking the juices from flowers and leaf-buds, and later by attacking tender fruits and shoots. The tarnished plant-bug is credited with being the author of "buttoning" of strawberries, and forms of "blight," the insect in the latter case acting as a transmitter of germs from dis- eased to healthy plants. Were it not that this plant-bug dis- tributed its attack by feeding on a variety of crops and weeds, it would be more injurious than it is. The bugs are extremely active, quick of flight as well as of foot, and when disturbed have the habit, in common with kindred species, of hiding by dodging to the opposite side of a plant. Hibernation is usually in the adult stage. In early spring, the females deposit their eggs singly on plants, continuing for two weeks or longer. According to Prof. J. M. Stedman, three generations develop in southern Missouri, and two in the northern portion of that state. The duration of the life cycle may be placed approx- imately at about four weeks, or a little longer, the length of time depending on season and climate. Remedies. — The standard bug remedy, kerosene emulsion, is the best, sprayed on as thoroughly as possible to all crop plants as well as weeds attacked. Pyrethrum is of value, but must be applied repeatedly and is rather expensive. Hand methods are also valuable, and a hand net is useful for sweeping the plants and surrounding grass and other vegetation. Frequently more individuals can be captured in this way than in any other. When a considerable number have been taken, they can be killed by throwing them into large pans of water with a few drops of kerosene. After the crop is off "back firing" should be practiced in the same manner as described as a remedy for army worms on page 58. GENERAL CROP PESTS SO, The Onion Thrips (Thrips tabaci Lind.). — Few gardeners are unacquainted with "thrips," of which there are several species injurious to plants grown under glass. The commonest and most destructive vegetable-feeding species in America are the onion thrips and the wheat thrips. All thrips are exceedingly minute, the common species not exceeding one-twentieth of an inch in length. They have Fig. 50.— Onion thrips. a, Adult; b, antenna of same; c, young larva; d, full-grown larva— greatly enlarged. (Howard, U. S. Dept. Agr.) elongate bodies, and the winged lorms have four very slender wings fringed with long, delicate hairs. These insects are somewhat anomalous in the manner of their feeding: their mouth-parts are fitted chiefly for sucking, but they also have bristle-like mandibles. The general appearance of the onion thrips is shown in figure 50, a, highly magnified. It is pale yellow, with the thorax somewhat darker. The wings are paler yellow, with dusky fringes and bristles. The parent insects are usually found on the lower sides of leaves or imbedded in flowers of various kinds. In their attacks they induce the withering of the parts affected, and they some- times destroy entire plantings. The onion thrips injures a great variety of field and garden crops, to which it is quite as de- structive as to plants grown artificially. Besides onion it in- juriously affects garden leek, parsley, cabbage, celery, melon, 90 INSECTS INJURIOUS TO VEGETABLES cucumber, squash, turnip, cauliflower and strawberry, and does more or less damage to nasturtium, mignonette, carnations, candytuft, four-o'clock and rudbeckia. The female thrips cuts a slit, in a leaf or stem usually, to deposit her eggs. In a few days the young thrips work their way out and begin to feed. They suck the juices of plants and, as they feed continuously, their growth is rapid. The entire life cycle from the time of the deposition of the eggs until the maturing of the adult is passed under favorable conditions, in a warm atmosphere, in three weeks. Out-of-doors in a cooler atmosphere a longer period would be required for the life cycle. The minute size of thrips, with their habits of feeding by suction, in concealment in their host plants, renders it difficult to treat them successfully. The best contact poisons are dilute kerosene-soap emulsion, applied as for aphides (p. 361). It is practicable in some cases to dip whole plants, when being transferred from the hothouse to the field, in kerosene emulsion. For fumigation, hydrocyanic-acid gas, carbon bisulphid and different preparations of tobacco are useful. Tobacco prepara- tions, containing about 40 per cent, nicotine, have been found effective at the rate of 5 or 6 teaspoonfuls to 1^ pints of water when vaporized in a space of 5,000 cubic feet. This method does not injure cucumbers while nearly all the thrips on plants thus treated are killed. In the field drenching affected plants with a hose will kill many of the pests. Clean methods of farming is a necessity, as thrips develop largely in grasses, weeds and other vege- tation in and near onion fields. All other infested plants should also be treated with kerosene-soap emulsion, and the weeds burned where possible. The Wheat Thrips (Thrips tritici Fitch). — This native spe- cies, also called the strawberry midget, has been reported as GENERAL CROP PESTS 91 doing injury to parsley, pea, endive, cotton, orchard and small fruits and roses. Its color is yellow, with the thorax tinged with orange, and the antennae or feelers are ringed with a dusky color- (fig. 15). It is distributed from Canada to Florida, and westward. Remedies. — The same as for the onion thrips. The Red Spider (Tetranychus bimaculatus Haw.). — Few vegetables are free from the attacks of red spider (fig. 50^). These creatures are extremely minute, and are frequently not noticed until they become excessively numerous, as hap- pens during summer droughts. They do considerable damage in vegetable gardens and to plants grown under glass. Remedies. — Flowers of sul- phur, mixed with water at the ration of one ounce to the gallon, and sprayed over the plants, is of great value in eradicating this pest. Fish-oil and other soap solutions are Fi s- 50x.-Red spider, a, Adult; b. palpus; c, claws. (After Banks, U. S. Dept. Agr.) valuable, and the addition of sulphur increases their effectiveness, but are too strong for some delicate plants. Greenhouse plants are sprayed with water two or three times a week during the growing season, and care is exercised to wash off the spiders and not drench the beds. Fig. 51 -Spray of asparagus, with common asparagus beetle in different stages Natural size. (Author's illustration, U. S. Dept. Agr.) 92 CHAPTER VI INSECTS INJURIOUS TO ASPARAGUS Asparagus was introduced into America with the early settlers from Europe, and was cultivated here for two hundred years before being troubled with insects. Few edible plants down to the time of the Civil War have enjoyed such immunity from the ravages of insects. The principal insect enemies of asparagus are two leaf-beetles, both imported from the Old World, and limited for food supply to this plant. The Common Asparagus Beetle (Crioceris asparagi Linn.), as its English name indicates, is the more abundant asparagus Fig. 52.— Common asparagus beetle, a, Beetle; b, egg; c, newly-hatched larva; d, full-grown larva; e, pupa— all enlarged. (Author's illustration) beetle and by far the most important foe of this plant. Its first appearance was noted in this country at Astoria, near New York City, in i860, where it was introduced about 1856. The injury inflicted by this insect is due to the work of both adults and larvae upon the tender shoots, which they render unfit for market early in the season. Later they destroy by defoliation growing plants, and are particularly injurious to 93 94 INSECTS INJURIOUS TO VEGETABLES seedlings, the roots of which are weakened by having their tops devoured. Larvae, as well as beetles, attack the tenderest por- tions of the plants, but the latter gnaw with seemingly equal relish the epidermis, or rind, of the stems. The beetle, illustrated by figure 52, is a most beautiful creature, slender and graceful in form, blue-black in color, with red thorax, and lemon-yellow and dark-blue elytra or wing-covers, with reddish border. Its length is a trifle less than one-fourth of an inch. From the scene of its first colonization, Queens County, N. Y., the insect migrated to other truck-growing regions, and has now extended its range northward through Connecticut and Massachusetts to the State line of New Hampshire. Southward it has traveled to southern Virginia. At the present time it is well established in the principal asparagus-growing sections of the northern Atlantic region, and occurs westward to Illinois and Michigan. In a very few years we may expect its spread to other portions of states in which it is now local, and later it will naturally move westward. The insect passes the winter in the beetle state under con- venient shelter, and in April or May, according to locality, or at the season for cutting asparagus, issues from its hibernating quarters and lays its eggs for the first brood. The eggs are deposited endwise upon the stem or foliage and in early spring on the developing stalks, in rows of from two to six or more. In from three to eight days the eggs hatch, the young larvae, "grubs" or "worms," presenting the appearance indicated in figure 52, c. They at once begin to feed, and are from ten days to a fortnight in attaining full growth. When full grown the larva appears as in figure 52, d. It is soft and fleshy, and in color is dark-gray or olive, which becomes lighter and yellowish with age. The mature larva enters the earth, and here, within a little rounded, dirt-covered cocoon which it forms, the pupa state is assumed. In from five to eight or more days the beetle INSECTS INJURIOUS TO ASPARAGUS 95 is produced, which issues from the ground in search of food and of a suitable place for the continuance of the species. The duration of the life cycle, according to Fitch, is about thirty days from the time the egg is laid until the insect attains matur- ity. In the District of Columbia the eggs, in the warmest part of midsummer, develop in three and the pupae in five days. In the present range of the species two and perhaps three broods are usually produced. The beetles enter into hibernation in September. The asparagus beetle has efficient checks in predaceous in- sects, which prey upon its larvae and assist in preventing its undue increase. Among these are the spotted ladybird (Megilla maculata DeG.), the spined soldier-bug (Podisus maculi- vintris Say) and the bordered soldier-bug (Stiretrus anchor- ago Fab, fig. 53). Wasps and small dragon flies also prey upon the larvae. Im- mense numbers of beetles are «■ sometimes killed in winter dur- , 1t ... Fig. 53.— Bordered soldier-bug. Enlarged ing Severe cold spells follow- (Author's illustration, U.S. Dept.Agr.) ing "open" weather. Remedies. — The common asparagus beetle, under ordinary circumstances, may be held in restraint by the simplest means. Chickens and ducks are efficient destroyers of them, and their services are often brought into requisition for this purpose. A practice in high favor is to cut down all plants, including volunteer growth, in early spring to force the beetles to deposit their eggs upon new shoots, which are then cut every few days before the eggs hatch. Another measure of value consists in permitting a portion of the shoots to grow and serve as lures for the beetles. Here they are killed with insecticides, or the plants after they become covered with eggs are cut down and burned, and other shoots are allowed to grow up as decoys. 96 INSECTS INJURIOUS TO VEGETABLES One of the best remedies against the larvae is fresh, air-slaked lime dusted on the plants in the early morning while the dew is on. It quickly destroys all the grubs with which it comes in contact. The arsenicals, applied dry in powder mixed with lime, an- swer well, and possess the advantage of destroying beetles as well as grubs, and are of value upon plants that are not being cut for food. To produce satisfactory results the lime or arsenite must be applied at frequent intervals, or as often as the larvae reappear on the beds. Arsenate of lead is an excellent remedy. A simple method of killing the larvae in hot weather is to brush them from the plants so that they will drop to the heated earth, where they die before being able to return. The Twelve-spotted Asparagus Beetle (Crioceris 12-punctata Linn.). — The chief source of damage from this species is from the work of the hibernated beetles in early spring on young and edible asparagus shoots. Later the beetles as well as larvae ap- pear to feed exclusively on the berries. The eggs are deposited singly, and apparently by preference, on old plants toward the ends of shoots, which, lower down, bear ripening berries, and they are attached along their sides instead of at one end, as with the common species. Soon after the larva hatches from the Qgg it finds its way to an asparagus berry, enters it, and feeds upon the pulp. In due time it leaves this berry for an- other one, and when full growth is attained it deserts its last habitation and enters the earth, where it transforms to pupa and afterwards to the beetle. The life cycle does not differ materially from that of the common species, and there are probably as many generations developed. This species is at present distributed throughout nearly the~ same territory of the North as the preceding. The beetle rivals the common asparagus species in beauty, but may be distin- guished by its much broader wing-covers and color. It is orange red, and each wing-cover is marked with six black dots, and the knees and a portion of the under surface of the thorax are also INSECTS INJURIOUS TO ASPARAGUS 97 marked with black (fig. 54, a). The beetle as it occurs on plants when in fruit very closely resembles, at a little distance, a ripe asparagus berry. The full-grown larva is shown at figure 54, b. It measures, Fig 54 —Twelve-spotted asparagus beetle, a. Beetle; b, larva: c, second abdominal segment of larva; d same of common asparagus beetle, a, b, Enlarged; c, d, more enlarged. (Chittenden. U S Dept. Agr.) when extended, three-tenths of an inch, being of about the same proportions as the larva of the common species, but is readily separable by its ochraceous orange color. Remedies are those indicated for the common asparagus beetle, with the exception of caustic lime and other measures that are directed solely against that species, but the habit of the larva of living within the berry places it for that period beyond the reach of insecticides. The Asparagus Miner (Agromysa simplex Loew.). — Aspara- gus stalks are sometimes considerably injured by a maggot (fig. 55#, a) which mines under the skin near or just beneath the base. The appearance of the affected stalk (/) is charac- teristic. The parent insect is a small black fly. Remedial Suggestions. — Permit a few volunteer asparagus 9 8 INSECTS INJURIOUS TO VEGETABLES plants to grow as traps to lure the female fly to deposit her eggs Afterward, in late June or early July, pull the trap Fig. 55 —Criocevis 12- punctata. Egg, natur- al size, on asparagus, right; enlarged at left. (Chittenden, U. S. Dept. Agr.) Fig. 5 5x-— Asparagus miner, a, Larva; b, c, spiracles; d, e, puparium, /. section of asparagus stalk, showing injury and puparia. a-e, Much enlarged; /, slightly reduced. (Author's illus- tration, U. S. Dept. Agr.) plants and promptly burn them with their contained insects (in the flaxseed stage, fig. 55^, d, e). If this is carefully done over a considerable area, there will be little necessity for other methods, as few insects will be left for another season; unless, indeed, this insect has an alternate food plant. Cooperation and thoroughness are essen- tials for success. This method will operate also against the rust which is ofteji present in fields infested by the miner. CHAPTER VII . INSECTS INJURIOUS TO BEANS AND PEAS Edible legumes are subject to injury by certain weevils, which deposit their eggs upon or within the pods on the grow- ing plants and develop within the seed. The specific enemy of the pea is the pea weevil, and of the bean, the common bean weevil, both of sufficiently wide distribution and abundance to hold high rank among injurious insects. The inroads of these weevils in seeds cause great waste, and particularly is this true of seed kept in store for any considerable tmie. In former times popular opinion held that the germination of leguminous food seed was not impaired by the action of the larval beetle in its interior, but this belief is erroneous, as will be shown in the discussion of the nature of the damage by the pea weevil. Although it is not probable that any serious trouble follows the consumption by human beings of the immature weevils in green peas or beans, the use for food of badly infested dry seed filled with' the dead bodies and excrement of the beetles would naturally be attended with Unpleasant consequences. Growing pods in the fields are invaded by the bollworm and pea moth, and the foliage is preyed upon by numerous insects. Of foliage feeders are the bean leaf-beetle, bean ladybird, blister beetles, cutworms, and other caterpillars. Several forms of plant-bugs, leafhoppers, and aphides also exhaust the plants by sapping their juices. The Pea Weevil (Bruchus pisorum Linn.). — Seed peas are often found with a single round hole in them, due to the attack of the pea weevil or "pea bug," the largest of the pea and bean- 99 IOO INSECTS INJURIOUS TO VEGETABLES feeding weevils found in this country, measuring about a fifth of an inch in length. Its ground color is black, but it is thickly covered with brown pubescence, variegated with black and white markings arranged as illustrated in figure 57, a. ©In 1748 the celebrated Swedish naturalist Pehr Kalm gave an account of this weevil, stating that the culture of the pea had been abandoned in Fig. 5 6. -A Pennsylvania, New Jersey, and southern New buggy pea York on account of it. There are reasons for believing that this species came orig- inally, with so many other injurious insects which live upon cultivated seeds, from the Orient, and it has now become dis- tributed over nearly the entire globe, wherever peas are culti- vated. It does comparatively little damage in the colder parts of Canada; hence, seed peas for planting in the United States are largely imported from Canada or are bought from seed dealers who obtain them from our more northern states. Fig. 57.— Pea weevil, a, Adult beetle; b, larva; c, pupa. All greatly enlarged (Author's illustration, U. S. Dept. Agr.) Nature of injury. — Every pea in a pod is sometimes infested with this weevil ; and although nearly every one is familiar with "buggy" peas, it is not generally known that in eating green peas we often eat also a "worm" with nearly every pea. The only external evidence of infestation in a green pea is a minute INSECTS INJURIOUS TO BEANS AND PEAS IOI dot on its surface, but in dry seed the cell inhabited by the insect is visible under the skin. The belief was once more or less prevalent that the larva working within the seed, by some wonderful instinct, avoided the germ or embryo, and that weevil-infested peas were there- fore of equal value for seed to uninfested ones, but this is in- correct. Many "weeviled" seed will germinate, but as they are deficient in plant food the resulting plant is apt to be weakly and nonproductive. This species develops only a single generation annually. As it does not breed in dry peas, the new generation for another year is dependent on such beetles as are contained in planted seed or which escape from the storeroom. REMEDIES Holding over seed. — A simple and effective remedy consists merely in keeping seed peas in a close receptacle, a tight bag or box, over one season before planting. The beetles which issue die without being able to lay their eggs in the field. Primary injury to the seed has been effected by the larva the first summer and after the weevil develops, always during the first autumn in the writer's experience, further damage prac- tically ceases. Late planting. — Comparative immunity from pea weevil at- tack is claimed in some localities, e. g., in the southern states, by planting late, and is all that is necessary to secure sound seed stock. Bisulphid of carbon. — When it is desired to plant the first season after gathering the seed, bags in which peas have been kept tightly closed should be placed in a tight box or vessel and disinfected with bisulphid of carbon, at the rate of an ounce or two to ioo pounds of seed. This method will kill the weevils 102 INSECTS INJURIOUS TO VEGETABLES Fig. 58.— Common bean weevil. Greatly enlarged. (Author's illustration, U. S. Dept. Agr.) without injury to the germinative property of the seed. A similar remedy consists in soaking infested seed for one minute in boiling water. A longer time is apt to injure it for planting. No efficient preventive of in- jury is known, but cooperation in the treatment of infested seed would render further action un- necessary. The Common Bean Weevil (Bruchus obtectus Say). — The most formidable enemy to the culture of beans is the common bean weevil. In the nature of its attack it differs from the pea weevil in that it not only develops in the pods in the field but continues to breed for suc- cessive generations in seed, after harvest and storage, until the seed is useless for planting or as food for man or stock. As with peas, the market gardens of the North provide the dry seed for consumption and for planting in the Southern States. In and about Washington, D. C, it is next to impos- sible to procure a crop of beans uninfested by this weevil; hence, the stores of the city are supplied mainly from the North, New York State furnishing the greatest quantities. This bean weevil is smaller than the preceding, averaging about an eighth of an inch in length. It is coated with fine brown-gray and olive pubescence which gives the body that col- or. The wing-covers are mottled, as shown in figures 58 and 60. From the pea weevil this species may be known by the different shaped thorax and the two small teeth in addition to the large tooth with which the thighs are armed. In figure 60, a, the beetle is represented in profile with its head bent under in natural INSECTS INJURIOUS TO BEANS AND PEAS 103 resting position. Until recently this species, like the preceding, was generally believed to be indigenous. It is certainly not native to the United States, and if introduced from the Eastern Hemisphere probably became acclimated in tropical America before establishing itself in the North. Its distribution is now Fig. 59.— Bean showing in jury- by common bean weevil. (From Riley.) Fig. 60.— Bean weevil, a, In profile; b, section of bean-pod showing slit for egg deposit; c, portion of interior of pod showing egg mass inserted through slit, a, c, Much enlarged. (Reengraved from Riley, U. S. Dept. Agr.) world-wide. It occurs in nearly every State and Territory of the Union, and is generally diffused through Central and South America. Oviposition takes place primarily in the field, the eggs being deposited, as with the pea weevil, upon or inserted in the pod through a hole made by the female and through openings, such as are caused by its drying and splitting. In shelled beans the eggs are dropped loosely in the receptacle in which they are stored, or are placed in holes made by the weevils in their exit from the seed. Less seldom they are attached to the outer surface of the seed. There are probably produced annually an average of six generations in latitudes such as the District of Columbia and a less number in more northern localities. Unlike the pea weevil, a large number of individuals will develop in a bean, as many as twenty-eight having been found in a single seed. 104 INSECTS INJURIOUS TO VEGETABLES Any single indoor generation is capable of exhausting seed and completely ruining it for food or planting or any other practical purpose. The beetles begin to issue in the field in a climate like that of the District of Columbia as early as October, when in the natural course of events the eggs for a new brood would be deposited in such pods as had cracked open so as to expose the seeds within. This beetle prefers the bean as a host plant, but it will also breed in cowpeas in the field as well as in store, and in confinement develops in dried peas, lentils, and chick- peas. It is no more true of seed infested by this species than of that attacked by the pea weevil that germination is not im- paired by the work of the weevil in the bean. Weeviled beans should not be planted. In a test only 50 per cent, of the infested seed used germinated, and only 30 per cent, could have passed the germinating stage, and these, owing to injury to the seed leaves, would probably have produced plants of low vigor and correspondingly low productiveness. Remedies. — From the fact that this species breeds continuously in dried seed, neither the expedient of holding over seed for a year before planting nor that of planting late for seed stock would be productive of good, as in the case of the pea weevil. Recourse must therefore be had to fumigation or to heat, and the earlier the seed is treated after it has been gathered the better the result. Just before it is planted seed infested with this bean weevil should be lightly thrown into water. Badly injured seed will float, and may be picked out or poured off and destroyed. Sound seed only should be reserved for planting. The Cowpea Weevil (Bruchus chinensis Linn.). — Cowpeas are quite liable to be infested by the cowpea weevil and the four-spotted bean weevil, which injure its seed in the same manner as the common bean weevil. Like that species they begin work in the field and continue to breed in the stored seed, INSECTS INJURIOUS TO BEANS AND PEAS 10$ until they entirely spoil it, or seriously impair its germinating power. Both species are generally distributed and injurious in the South, and are widening their range with the increasing use of their food plant as a soil renovator and as forage. They resemble each other after a manner superficially, in appearance as in habit, but they differ to some ex- tent in various details of their life econ- omy as well as in structure. The cowpea weevil may be readily dis- tinguished from the kindred four-spotted species by the two large, elevated ivory- like lobes at the base of the thorax and by the strongly pectinate antennae of the male (fig. 61). This is undoubtedly an Old World species and an ancient enemy Fi f; *i --Cowpea weevil r J (Author's illustration. of edible pulse. u. s. Dept. Agr.) Cowpea is the favorite food seed, but the insect is also injurious to common and pigeon peas, lentils, chick-pea and "mungo." Table beans also serve as food. Mate- rial infested by this weevil undergoes a marked elevation in temperature. In one instance the temperature of a small sack of seed infested by the cowpea weevil was found to be 25 F. higher than the surrounding atmosphere. Remedies. — The similarity of the habits of this and the com- mon bean weevil renders it amenable to the same remedies. The Four-spotted Bean Weevil (Bruchus quadrimaculatus Fab.) is the more slender species and differs from the cowpea weevil by many characters. What appears to be the commonest form of coloration is illustrated in figure 62, a, which is suffi- cient to separate it from the preceding which it much resembles, especially in its manner of life. The Remedies are practically the same as for the common bean weevil. I06 INSECTS INJURIOUS TO VEGETABLES The Seed-corn Maggot (Pcgomya fusciceps Zett). — When the seeds of beans, peas, corn and other plants fail to develop, damage is frequently due to a maggot which works by scraping the seeds, sprouts, roots, stalks, and stems of plants underground. 1 Where this insect works decay soon sets in and the plants die. Entire plantings are sometimes destroyed, but when only a few seeds or sprouting plants are attacked, Fig. 62.— Four-spotted bean weevil, a, Beetle; b, larva; c, pupa All enlarged. (Author's illustration, US. Dept. Agr.) injury may escape notice. Early crops suffer most and if they can be preserved until larger growth they will as a rule sustain considerable attack without material damage. The insect in question is called the seed-corn maggot and bean fly, and its parent looks like a small house fly. It can be identified by the male (fig. 63, a). 2 The female can scarcely be distinguished from related species, such as the adults of the cabbage root-maggot and onion maggot. The length is about one-fifth inch and the wing expanse about two-fifths. The larva is footless and of cylindrical form (d), narrowed at the anterior extremity and, enlarged posteriorly. It is considerably smaller 1 Injury of this character is also committed by wireworms, white grubs and some other insects, e. g., weevils in the seeds. 2 His principal characteristics consist of a row of short, rigid, bristly hairs of nearly equal length on the inner side of the posterior tibiae or shanks. INSECTS INJURIOUS TO BEANS AND PEAS 107 than the ©nion maggot, measuring about one-fourth of an inch. This fly is evidently of European origin, and was first rec- ognized in New York State in 1856. Like so many other flies, it ranges through several life areas, and we know of its occur- rence in New England, Canada and Minnesota, southward to the Gulf, and westward to the Pacific. Injury is most severe to young plants, and particularly to beans, peas, and Indian corn. Cabbage, turnip, radish, beets, 9> 4 Fig-. 63.— Seed-corn maggot, a, Male fly," c, head of female; d, larva, from side; e, anal segment of larva; /, anal spiracles; g, thoracic spiracles; h, puparium. All much enlarged. (Author's illustration, U. S. Dept. Agr.) onion, seed potato and hedge mustard are also attacked, and the maggots even feed on the eggs of grasshoppers. The insect apparently breeds on decaying vegetable and perhaps animal matter of various kinds. A single generation only develops in corn, but later ones might be produced on bean and pea, owing to the longer period in which these crops are grown. The flies are found southward throughout the year, but in the north there must be a period in midwinter in which breeding ceases; per- haps also another in midsummer. I08 INSECTS INJURIOUS TO VEGETABLES METHODS OF CONTROL Owing to the difficulty of destroying root-maggots and the cost of the chemicals, growers depend largely upon methods of prevention which should be employed before the insect's eggs are laid. Sand and kerosene, for deterring the parent flies from de- positing their eggs, consists in placing sand soaked in kerosene — a cupful to a bucket of dry sand — at the base of the plants, along the rows. This will also kill young maggots that might attempt to work through it. Mineral fertilisers are useful as deterrents, if employed just before or after a shower has thoroughly wet the ground. The principal fertilizers for the purpose are kainit, nitrate of soda, and chlorid of potash. They are used as top dressings before planting; and afterwards, when they should be applied as nearly as possible to the roots, the earth being turned away from the plants for this purpose. These fertilizers possess the advantage of acting also as a stimulant to plant growth, thereby facilitating recuperation from root-maggot attack. Danger from organic fertilisers. — Stable manure and organic fertilizers are apt to induce infestation, since this species devel- ops in excrement and other decomposing material. Numerous instances of this have come to the writer's knowledge. It is advisable, therefore, to avoid the use of manure, rotted leaves, or other organic fertilizers, and to avoid planting in fields in which there have been infested or diseased plants. Hellebore is used with some degree of success in Canada as a remedy for the cabbage and onion maggots. Carbolic acid emulsion diluted about 35 to 50 times, is partic- ularly applicable when this species occurs in radish and other plants than cabbage and cauliflower. Hand-picking, although laborious, has the merit of effective- ness and has been practiced with much success by extensive growers. It consists in lifting out the young plants, examining INSECTS INJURIOUS TO BEANS AND PEAS IO9 the roots for the maggots, and washing them in a strong solu- tion of soap, after which they are replanted and in two or three weeks show no ill effects of the treatment. By careful watching the eggs may be seen about the stalks of the young cabbage plants, and if the soil about these plants be raked away so as to expose the eggs to the sun they will dry up, thus preventing the maggots from hatching. Covering young plants of cabbage and cauliflower in seed- beds is also practiced with some success in Canada. The Bean Ladybird (Epilachna corrupta Muls.). — This species is limited in its operation as regards the number of crop plants ah o d Fig. 64.— Bean ladybird, a, Larva; b, beetle; c, pupa; d, egg mass. All about three times natural size. (Author's illustration, U. S. Dept. Agr.) affected and the territory invaded. It is one of three native ladybirds that live by choice on vegetables, the ®thers being predaceous and subsisting largely on plant-lice and soft-bodied larvae. It is nearly hemispherical, and its length is a little more than a fourth of an inch. In color it is light yellowish brown, and each wing-cover bears four black spots (fig. 64, b). Its distribution comprises Colorado, New Mexico, Arizona, western Kansas, and Mexico. The insect is described as being the worst enemy to the bean crop in the West, its work being compared to that of the Col- orado potato beetle. It devours all parts of a bean plant, leaves, flowers, and green pods. The female deposits her yellowish- brown eggs in large clusters (fig. 64, d), and the larvae feed chiefly on the lower sides of the leaves. The full-grown larva no INSECTS INJURIOUS TO VEGETABLES (a) is yellow and covered with stout branched spines. Winter is passed in the adult stage, and a single generation has been observed. Remedies. — Arsenate of lead is preferable to Paris green for use on beans since, unless great care be taken in the application of the latter, it is liable to scorch the leaves. Kerosene emul- sion has given good results, and is not open to the objection Fig. 65.— Bean leaf-beetle, a, Adult beetle; b, pupa; c, larva; d, side view of anal segment of larva; e. leg of same; /, egg', a, b, c, Enlarged about six times; d, e, f, more enlarged. (Author's illustration, U. S. Dept. Agr.) of poisoning the plants as in the case of an arsenical. Hand- picking the beetles and eggs on their earliest appearance is a measure of prevention that would compensate for the time and labor in kitchen gardens. The Bean Leaf -beetle (Cerotoma trifurcata Forst). — An in- sect of considerable importance in the Gulf States, and in some years farther north is the bean leaf-beetle. It has attracted at- tention by its injuries in New Jersey, Louisiana, Indiana, Dela- ware, Ohio, Maryland, and Virginia. Injury is due to the adult beetle, which eats large, round holes in growing leaves of bean and cowpea, and certain other leguminous plants, including INSECTS INJURIOUS TO BEANS AND PEAS III cultivated beggarweed or tickseed. The larvae feed on the roots and main stems of the same plants just below the surface. The beetle resembles in several particulars the cucumber beetles. It measures from a seventh to a fifth of an inch in length, and varies in color from pale yellowish or buff to dull greasy red, with black markings, arranged, in what appears to be the typical form, as in figure 65, a. Individuals occur, how- ever, in which the elytral marking is entirely wanting. This species is native and found from Canada southward to the Gulf States and westward to Kansas and Minnesota. In the South the beetles appear in April, and northward as late as June. The minute orange-colored eggs (fig. 65, /) are laid about the stem of the insects' food plant, in clusters of six or more, and the larvae eat around the stem and roots. Remedies. — Hand-picking and pyrethrum are useful in small gardens early in the season; but our chief reliance is in arseni- cals when the insect is numer- ous. Arsenate of lead should be employed on the first appear- ance of the beetles in order to stop them at the outset. An important measure is the care- ful weeding out of wild food plants, such as tick trefoil and bush-clover, in the neighborhood of cultivated fields. The Pea Moth (Semasia nigricana Steph.). — In Canada, where pea-growing is an important industry, there is, in addition to the pea weevil discussed in previous pages, a seed-infesting in- sect known as the pea moth, the larva of which develops in ripening peas in the pods. The moth (fig. 66) is a small Tortricid, with a wing expanse of about half an inch. The Fig. 66.— Pea moth (Steph) Moth above, larva below. About three times natural size. (Author's illustration, U. S. Dept. Agr.) 112 INSECTS INJURIOUS TO VEGETABLES larva is whitish-yellow with a pale brown head and thoracic shield, the latter inconspicuous. This is a comparatively new importation from the Old World and it is as yet unknown in the United States, but it will probably in- time invade our Northern States, and pea-growers should be warned against it. The remedy which gives best results is early planting of the earliest ripening varieties. The Bean Leaf -roller (Eudamus proteus Linn.). — This species is injurious in the Gulf States to beans, cowpea and cultivated Fig. 67.— Bean leaf-roller, a, Butterfly; b, larva, dorsal view; c, larva, lateral view; d, pupa in rolled-up leaf. Somewhat enlarged. (Author's illustration, U.S. Dept. Agr.) "beggarweed." It is the caterpillar of a butterfly called the swallow-tailed skipper. The ground color of the caterpillar is yellowish, its head being darker and marked with two orange spots near the mandibles. The head is prominent and separated from the body by the narrow neck, a character which will dis- tinguish it from any other common caterpillar on garden crops (fig. 67). INSECTS INJURIOUS TO BEANS AND PEAS 113 Cutworms and Other Caterpillars. — Numerous other caterpil- lars devour the foliage of beans and peas of which cutworms are among the most important, often causing extensive damage to young plants by cutting them off near the ground, and to older plants by severing their leaves and tender shoots. Cut- worm remedies are considered on page 54. A green-striped caterpillar (fig. 68), misnamed the bean cut- worm (Ogdoconta cinereola Guen.), does injury to the foliage Fig. 68.— Bean cutworm Ogdoconta cinereola). a, Moth, b. larva; c, abdominal seg- ments of larva; d, pupa. All enlarged. (Author's illustration, U. S. Dept. Agr.) and pods of beans, sometimes stripping the vines bare. Other troublesome species include the zebra caterpillars, the yellow bear and salt-marsh caterpillars. The boll worm or corn-ear worm (Heliothis obsoleta Fab.) is a very serious enemy of beans frequently destroying the seed by crawling into the green pods. No means of preventing this form of injury is known. A more extended account of this pest will be given under "Insects Injurious to Sweet Corn." The caterpillar of a beautiful little butterfly, the gray hair- streak (Thecla melinus Hbn.) is sometimes injurious to beans and peas by eating into the pods. The butterfly is on the wing almost continuously from May to September in the North, and from March to November farther South. This species seldom H4 INSECTS INJURIOUS TO VEGETABLES does severe damage, hence little precaution need be observed in the treatment of it, further than to destroy all affected pods, 4flk Fig. 69.— Gray hair-streak, a, b. Butterfly; c, larva; d, pupa; e, egg, much en- larged; others somewhat enlarged- (Howard & Chittenden, U. S. Dept. Agr.) that the insect may not develop and do injury later and in after years (fig. 69). It may be successfully controlled by a spraying with an ar- senical on its first appearance. The Pea Aphis (Nectarophora destructor Johns.). — Until the year 1899 P eas grown in the United States suffered little injury from insects other than the pea weevil. In that and the fol- lowing year, however, this crop was badly injured by the pea aphis, which caused enormous losses in our principal pea- growing regions, especially where peas are grown for canning. It was, in fact, one of the most destructive of all insects that ravaged crops in the United States at that time. This aphis is of unusual size among those found in gardens, and the largest green species which attack the pea and related plants. The length of the body of winged viviparous females is about 3/16 inch, and the total wing expanse about 4/10 inch. The general color of both the winged and apterous or wingless forms is uniform pea-green, the same as its food plants. As to whether this insect is native or of foreign origin there is still some doubt. INSECTS INJURIOUS TO BEANS AND PEAS II5 During the years mentioned this pea aphis overran and laid waste fields, of peas from Nova Scotia to Virginia and Mary- land, in the last as well as neighboring States, destroying about 50 per cent, of the annual output, and this in spite of vigorous efforts that were made to control it. An estimate of the loss for 1899 along the Atlantic Coast States reached the sum of Fig. 70.— Pea aphis, a, Winged female; b, same from side with wings folded in natural position when feeding; c, apterous female; d, nymph in last stage; e, third joint of antenna of winged form, a-d, Much enlarged, e, more highly magnified. (Author's illustration, U.S. Dept. Agr.) $3,000,000. During 1900 the loss over the same area was placed as early as June 15 at $4,000,000. Several cases of severe damage were reported, in which 80 or more per cent, of the peas on farms of 500 or 600 acres were completely destroyed. In short, pea-growers as far westward as Wisconsin sustained such severe losses as to give rise to the expression that the country had been visited by a veritable scourge. Attack begins on the young vines ; the "lice" gather in clusters about the terminals, and as the leaves become covered they attack the stems, and by their numbers and voracity sap the life of the plant. Whole areas are frequently seen covered with Il6 INSECTS INJURIOUS TO VEGETABLES the "lice," which in a very few weeks destroy a crop. Attack is seldom noticed until May in the more Southern States in which the insect is found, and a little later in its more northern range. It hibernates on clover and vetch, and from these plants spreads by flight in April and May to peas. The females at certain periods produce living young. These attain maturity in from ten to fifteen days, and possibly in less time in the hottest weather. Several generations develop each year. As instance of the reproductive powers of this insect, Prof. W. G. Johnson's estimate is interesting. Females produce from no to 120 young. Calculating from the average number of insects produced each day (six), one individual would in one year become the pro- genitor of 423,912 "lice." In some instances natural enemies of the pea aphis have done efficient service. Seldom, however, do they destroy the insects sufficiently early in the season to save a crop. REMEDIES Kerosene-soap emulsion, carefully prepared and diluted with about twelve parts of water, and sprayed upon the plants upon the first appearance of the "lice," so that the leaves are wet on both the under and upper surfaces, has been found to be the most effective of the insecticides tried. A stronger solution is apt to scald the plant, particularly while the vines are young and tender. The cost of the emulsion, however, and the diffi- culty of under-spraying, its rapid evaporation, and the necessity of frequent applications, is such as to hardly warrant its use. Brush and cultivator method. — The peas are grown in rows sufficiently wide apart as to admit of a one-horse cultivator be- tween them. The "lice" are brushed from the plants with boughs of pine with their leaves on, and a cultivator follows down the rows immediately afterward. This method should be practiced in the heat of the day, when the ground is dry and hot, and a repetition of the brushing is necessary every three INSECTS INJURIOUS TO BEANS AND PEAS II7 to seven days until the crop is ready for picking. Such "lice" as are not buried in the ground will be killed by the dust which closes their breathing pores, while a considerable proportion are destroyed also by the force of the brushing. Peas planted in rows to permit of frequent cultivation suffer much less injury than when sown broadcast. As soon as the last picking has been made infested plants should be promptly plowed under. Cultural methods. — Of cultural methods there is testimony to the value of early planting, the earliest peas seldom being in- fested, or at least only slightly injured. Very late plantings of peas for canning have also escaped ravages in some instances. Rotation of crops is advisable, and it is unwise to plant peas in successive years in the same portion of a farm, or in the vicinity of other leguminous plants likely to harbor this species. As this insect passes the winter on the plants mentioned, because peas are not available, it might be possible to use small plats of some of them as trap crops. Crimson clover would probably be best because of the early start that it gets in the spring. On the trap plants the "lice" could be killed by hand methods, such as brushing from the plants into pans, and thus large numbers Fi ^ '' 1 - -cratcy leaf hopper. r . . Adult - (Author's illustration, could be killed early in the season be- u. s. Dept. Agr.) fore they had opportunity to spread to peas. Leafhoppers of several species occur in all stages, feeding on the under surface of leaves of bean and cowpea, but are not known to be particularly injurious. The most conspicuous species, on account of its large size and bright colors, is the crafty leaf hopper (Diedrocephala versuta Say, fig. 71). Rem- edies have been discussed on page 86. Plant-bugs are often abundant on edible legumes. Of these Il8 INSECTS INJURIOUS TO VEGETABLES the garden flea-hopper (Halticus uhleri Giard) lives in great numbers on the leaves, puncturing them so as to cause the death of the tissues in small irregular white patches. In its snort- winged form (fig. J2, a) it resembles the black flea-beetles, which affect potato, alike in appearance, in the nature of its work, Fig. 72.— Garden flea-hopper, c, Brachypterous female; b. full-winged female. All much enlarged. (Author's illustration. U. S Dept. Agr.) and in its saltatory power. Other food plants include potato, pumpkin, cabbage, ornamental plants, clover and many weeds. Remedies are the same as for leafhoppers. Beans, peas and other plants subject to injury should not be planted in or near old clover fields. Nuttall's Blister Beetle (Cantharis nuttalli Say).— Blister beetles do much injury to leguminous food crops and are par- ticularly harmful to beans and peas. Nuttall's blister beetle is a large and. beautiful insect, variable both in color and size (fig. 73). It is bright metallic green, the head and thorax have usually a coppery luster, and the wing-covers are often purple. It varies from a little over half to nearly an inch. Its habitat extends from the northern Mississippi valley region to the Rocky Mountains, and it is abundant from South Dakota to the northwest territories of Canada. It is related to the Spanish fly, the Cantharis vesicatoria or cantharides of commerce, has INSECTS INJURIOUS TO BEANS AND PEAS 119 the same blistering properties, and might be put to the same use. The beetles make their first appearance about the first of July, ravenously devour the blossoms and tender leaves of beans and other vegetables, and, if report speaks truly, they are capable of destroying a crop in a day. From the rapidity with which this insect works, poisons are of little value. We must, therefore, resort to mechanical meas- ures, and in their employment promptness and thoroughness are Fig. 73.— Nuttall's blister beetle. One-third larger than natural size. (Author s illustration, U. S~ Dept. Agr.) Fig. 74.— Ash-gray blister beetle. Female at right, twice natural size; male antenna at left. Greatly en- larged. (Author's illustration, U. S. Dept. Agr.) essential. The beetles may be destroyed by driving them into windrows of dry straw or similar material and burning them; by sweeping them into a net, such as is used by insect collectors, and throwing the captured insects into a fire ; or by beating them into specially prepared pans of water on which there is a thin scum of coal oil. The Ash-gray Blister Beetle (Macrobasis unicolor Kby.). — This is one of our commonest Eastern species (fig. 74), and although very destructive to beans and peas, is also a serious enemy of beets, potato, and tomato, and attacks besides sweet potato and some flowering plants. Blister beetle remedies are discussed on page 68. CHAPTER VIII INSECTS INJURIOUS TO BEETS AND SPINACH The recent extension of the sugar-beet industry in this country has been the means of bringing to notice a large number of insects not previously identified with that plant. Owing to its lesser prominence as a merchantable product, spinach is not grown to the same extent, and it follows that its known insect enemies are fewer still. With the exception of some insects which will be mentioned, the majority of those which live more or less habitually on beets and spinach feed normally on related wild plants, including the goosefoot, amaranth, saltbush and the like. During the last quarter century several insects have been so prominent as pests in fields of sugar-beet, that they have received names indicative of their beet-feeding habit, while some few take their common names from spinach. Of these are the beet army worm, beet webworm, spinach leaf-miner, spinach flea-beetle, beet carrion-beetle and the beet aphis. Up to 1907 nearly 200 species of insects have been observed to use beets as food. The greatest losses from insect attack are probably due to flea-beetles, but they, as well as cutworms and similar groups, are so irregular in their depredations that an exact estimate cannot be made. Different species of leaf-beetles and cater- pillars, other than cutworms, do more or less injury, and several blister beetles devour the foliage of sugar and table beets freely ; most forms of the last, however, usually make their appearance so late in the season that, although defoliation may be excessive, comparatively little damage is accomplished. The same is true of some species of grasshoppers. Two common forms of farm 120 INSECTS INJURIOUS TO BEETS AND SPINACH 121 insects, white grubs and wire worms, are at times injurious to the roots, and root-aphides injure the roots so as to render them comparatively useless. FLEA-BEETLES AND LEAF-BEETLES As flea-beetles are among the most troublesome sugar-beet "pests from their early occurrence and the rapidity with which Fig. 75. — Spinach flea-beetle, a, Beetle; b, egg mass, showing mode of escape of larva at right; bb, sculpture of egg; c, full-grown larva; d, pupa; e, newly-hatched larva; /, abdominal segment of same, a, c, d, Five times natural size; b. e, more enlarged; bb, f, still more enlarged. (Author's illustration, U.S. Dept. Agr.) they work, they may receive first mention, especially as no less than twenty forms have been observed attacking this plant Some of these are widely distributed ; others are local. Most farmers are familiar with flea-beetles, better known perhaps as "fleas," and it will be unnecessary to enter into detail in regard to more than one species. The Spinach Flea-beetle {Disonycha xanthomelcena Dalm.). — This flea-beetle (fig. 75) is black with a reddish-yellow thorax. It appears early and, like other species of its kind, works 122 INSECTS INJURIOUS TO VEGETABLES rapidly. It can be controlled in the same manner as other flea- beetles and leaf-beetles, and there is no doubt that if growers took pains not to allow chickweed and lambsquarters to spring up in the fields that the insect could be still more easily de- stroyed, as the first generation is produced on this and some similar weeds, and it is the second generation which attacks the beets. Its young, or larva, has the same habit as the adult, and the species frequently "cleans out" entire rows of beets before its appearance is suspected. Remedies for flea-beetles are discussed on page 65. The Larger Beet Leaf -beetle (Monoxia puncticollis Say). — Two species of native leaf-beetles are important enemies of the sugar-beet in the West, where they are sometimes known as "French bugs" and "alkali bugs." The larger beet leaf-beetle (fig. 76) lays her eggs on the under side of leaves, where they hatch in about six days, the young larvae commence feeding at once, continuing for nine or Fig. 76 —Larger beet leaf-beetle, a, Female beetle; b. eggs; c. larva; 6 , male claw; ? , female claw. All much enlarged, claws more enlarged. (Author s illustration. U. S. Dept. Agr.) ten days, when they dig their way into the ground, and, a few days later, come forth as beetles. Damage is due to both the larvae and beetles, hundreds occurring on a single plant, which INSECTS INJURIOUS TO BEETS AND SPINACH 123 is either consumed or so injured that it shrivels and dies. Since 1897 this species has done more or less injury to sugar-beet in Colorado, Idaho, Utah and neighboring States, the beetles often occurring in swarms like blister beetles. This species resembles the elm leaf-beetle, but is larger and differently marked. It is oblong, narrow in front and dull brown while the wing-covers are more or less distinctly striped. The Western Beet Beetle (Monoxia consputa Lee). — Beets are much injured by this species along the Pacific Co-ast. It Fig 77.— Western beet beetle. Eight times natural size; antenna Fig. 78— Margined blister at left highly magnified. (Author's beetle. Enlarged. (Author's illustration, U. S. Dept. Agr.) illustration, U. S. Dept. Agr.) eats holes through the leaves, in some instances leaving only a network of the original leaf, and this seriously interferes with the growth of young plants, which are sometimes killed. This beetle (fig. 77) is closely related to the preceding, but is smaller, measuring only about one-sixth of an inch in length. Remedies. — These beet leaf-beetles are important enemies of sugar-beet culture. The general methods for the control of leaf and flea-beetles (see page 65) are applicable, but a few remarks should be added in regard to particular remedies. Paris green, London purple, and paragrene have all been employed against the larger species with apparently good results when applied 124 INSECTS INJURIOUS TO VEGETABLES dry, mixed with flour, in the same manner as for the Colorado potato beetle. The beetles accumulate quite largely upon "mother" beets early in spring, which suggests that if a few beets be left in the ground over winter they will serve as trap crops for the protection of the younger plants in spring. The larger species practically confines its injuries to plants growing in or in close proximity to alkali soil. Hence such ground is to be avoided for the cultivation of beets. BLISTER BEETLES Blister beetles are among the most conspicuous of all beet enemies, and no less than n species have been observed as doing injury to sugar-beet alone. One of the commonest is the margined blister beetle (Epicauta marginata, fig. 78). The writer has seen entire plantings of beet almost completely de- foliated by it; but as a rule this and several of the other beet- feeding blister beetles occur too late in the season to do material harm, as the roots have by this time made nearly complete growth. This species also attacks beans, potatoes and tomatoes, as well as other vegetables, and is destructive to some flowering plants. It is most abundant in July and August. Remedies are the same as for other blister beetles (page 68). CUTWORMS AND OTHER CATERPILLARS When sugar-beets are cultivated over a large territory, there is comparatively little danger of injury from common cutworms which are such serious pests in the vegetable garden. Certain species, however, occur occasionally in great numbers, spreading from field to field, like the army worms, and sometimes sweep everything before them, as they feed upon every portion of the plant — foliage, flowers, stalks, and even roots. At such times they should be promptly destroyed. Methods of control employed against cutworms are considered on page 54. When traveling in armies cutworms should be treated as army worms (see p. 58). INSECTS INJURIOUS TO BEETS AND SPINACH 125 The Beet Army Worm (Laphygma exigua Hbn.).— This species has come into prominence since the extensive cultivation of the sugar-beet in the West. It is rapidly widening in distribu- tion, chiefly by the flight of the mature insect, a moth resembling the parents of the cutworms. This insect might be a still more injurious sugar-beet pest than is yet known, save for the fact that it attacks many other crops and weeds. The moth (fig. 79, a) is of a gray color, resembling the plain form of the fall army worm, to which species it is related. The Fig. 79.— Beet army worm, a, Moth; b, larva, lateral view; c, larva, dorsal view: a. head of larva; e, egg, viewed from above; f, egg, from side. All enlarged. (Author s illus- tration, U. S. Dept. Agr.) fore-wings are broader and paler, and the reniform and other spots as well as mottlings are more distinct. The wing expanse is less than an inch and one-half. The larva is striped, as shown at b and c. Remedies. — When occurring in numbers this insect can be controlled by means of an arsenical, but when unduly abundant, army worm remedies are necessary. The Beet Webworm (Loxostege sticticalis Linn.).— This in- sect is, like the preceding, of foreign origin, and is also rapidly 126 INSECTS INJURIOUS TO VEGETABLES increasing its range, and as it has developed an unusual fond- ness for sugar-beet it will in time become a beet pest of great importance. It has evidently been introduced on the Pacific Coast and has been found destructive as far eastward as Michigan and Nebraska, and has done considerable injury in other localities, including Canada where it was recently very destructive. It is cousin to the native garden webworm, which it resembles in general form. It is, however, darker and about Fig. 80.— Beet webworm. a, Moth, twice natural size; b, larva, less enlarged; e, upper surface of first proleg segment of larva; d, side view of same; c, d. more enlarged. (After Insect Life.) one- fourth larger. Fully expanded the wings measure nearly an inch, and are purplish brown in color, with darker and paler bands, as shown (fig. So, a). The hibernating caterpillars make a burrow beneath the surface of the ground and construct a cocoon about three times as long as themselves. A similar but shorter cocoon is made by the midsummer brood. A favorite wild food plant of this species has been observed — the pigweed or careless weed (Amaranthus) — and injury to sugar-beet has been observed in many cases where the ground was allowed to run to the wild plant. Remedies. — The, destruction of this and other weeds might in time lead to comparative immunity from the attack of the webworm. Paris green or other arsenical sprayed several times over the infested plants will also compass its destruction. INSECTS INJURIOUS TO BEETS AND SPINACH 127 Other kinds of caterpillars, including such well-known forms as the zebra and salt-marsh caterpillars, are often found in beet fields, but seldom in sufficient numbers to do serious injury. As a rule they readily yield to sprays of Paris green. GRASSHOPPERS Grasshoppers, or locusts, as well as crickets and some related insects, are of great importance in the West, and frequently do injury to sugar-beets. Many species attack this plant. Remedies. — The hopper-dozer is a necessary implement in our warfare against this class of pests, It is discussed with other grasshopper remedies on page 71. Fig. 81 — Beet leaf-miner, a, Fly; b, head of male fly; c, head of female; d> surface of egg, highly magnified; e, egg," /, maggot; g, head of same; /, anal segment; k, anal spiracles. All enlarged. (After Howard, U S. Dept. Agr.) LEAF-MINERS Hitherto insects which affect chiefly the foliage by chewing have been treated. We now come to a consideration of insects 128 INSECTS INJURIOUS TO VEGETABLES of different habits, and among these are the leaf -miners — small, white maggots producing two-winged flies resembling the house fly. These burrow between the two surfaces of the leaves and form blotches termed mines. The principal species, the beet or spinach leaf-miner (Pegomya vicina Lint.), is illustrated (fig. 81). We have not as yet ascertained any perfectly satis- factory remedy for the leaf-miners. PLANT-BUGS, LEAFHOPPERS AND APHIDES Hordes of sucking insects, many plant-bugs, leafhoppers and numerous related forms are present in fields of sugar-beet at all times, and sometimes accomplish very considerable in- jury. Among the most prominent of these are the false chinch- bugs. The most satisfactory manner of keeping false chinch-bugs in check is by clean farming methods, destroying purslane and other weeds, and the cleaning up of crop remnants before winter, so as to leave no place for the insects to pass the winter. Some growers have observed that the flooding of fields infested by these insects forces them to leave, and the growing of mustard as a trap crop gives good results, provided the precaution is always taken to destroy the mustard before it runs to seed. The sugar-beet leafhopper (Eutettix tenella Baker) came into prominence as a beet pest in Utah, Idaho and Colorado in 1905, doing damage that year estimated at $500,000. This insect has become locally known as "white fly" and its injury as "blight." It has been noticed that late-planted beets are principally damaged and that early plants are less injured, and it may be that on this or a similar point in its life economy may hinge the remedy. It is worthy of remark that the species was un- known to science until 1900. For the aphides which attack sugar-beet, it is sometimes un- INSECTS INJURIOUS TO BEETS AND SPINACH I29 necessary to employ remedies, as these creatures are peculiarly susceptible to atmospheric conditions, doing their greatest in- jury in cool, damp weather, and being held in nearly complete abeyance at times by numerous natural enemies which flourish in dry and even hot weather, as is very well known. In gardens of table beets, kerosene emulsion, pyrethrum and fu- migation, according to directions given on page 165, are of value. Practically none of these remedies can be employed on large fields, but are useful in small ones. Clean farming and fall plowing are always advisable, and crop rotation should be prac- ticed where possible with potatoes or similar crop. Two species of root-aphides do great damage. They are the beet aphis and beet root-aphis. The Beet Aphis (Pemphigus beta Doane) ruined in one year in a single valley upwards of 1,000 tons of beets. This was in Oregon. The species also inhabits Washington, and probably California, and it is probable that it may be reckoned among the important beet pests of the future. Owing to the large acreage in sugar-beet growing regions of the United States we cannot successfully control the root-aphides by means of insecticides. It would be supposed naturally that heavy flooding and plowing in fall so as to expose the insects to the frost might control it, but this is sometimes a failure. Our knowledge of alternate food plants is somewhat limited, but we can recommend the avoidance of beet cultivation in land where other plants subject to the attack of this insect have grown; also crop rotation. If the aphides are found at work only in parts of a field, they could be destroyed here with kerosene emulsion applied preferably just before rainfall, or by following the application with a flooding of water. Root-aphides are almost invariably associated with ants, which foster them and act as distributers of infestation by car- rying wingless forms from plant to plant. It is therefore ad- visable to break up the nests of ants as fast as they are found. 130 INSECTS INJURIOUS TO VEGETABLES The Beet Root-aphis (Tychea brevicornis Hart, fig. 82) is most destructive in Colorado. It has a variety of alternate food plants, and we can only learn by experiment what are the best for rotation. We should avoid corn, sorghum, and other cereals, grasses, /(^^N^ Q^^ v^^ and particularly should we avoid U \ j| ^^ weeds, including wild grasses. Oth- erwise the remedies advised for the beet-aphis are suggested. ^ WHITE GRUBS AND Fig. 82.-*, Bean rocfaphis; b, WIREWORMS antenna; c, tarsus. Enlarged. (After A number of forms of white _ Carman. ) grubs and of wireworms attack beet roots, but none appear to favor this form of food. We have yet to learn of severe and extensive damage by them. Remedies. — Among the best remedies are fall plowing, rota- tion of crops, clean cultivation, in particular the suppression of grasses, the use of potash fertilizers as stimulants to the plants found affected, all of these remedies acting to a certain extent on both forms of insects. In this chapter there have been considered quite briefly the principal forms of insects which trouble the beet-grower or which he may expect to meet in his fields. Several of the in- sects mentioned in the last four pages require additional in- vestigation before definite and detailed instructions can be furnished for their suppression. For further information appli- cation should be made to the Bureau of Entomology of the Department of Agriculture. CHAPTER IX INSECTS INJURIOUS TO CABBAGE AND OTHER CRUCIFEROUS CROPS Cabbage is peculiarly susceptible to insect attack, and there are probably more species of insects that injure it than any other truck crop. Other edible cole plants are attacked by the same species of insects, but as a rule suffer rather less injury. At- tack begins from the time the seeds commence to sprout and continues in the case of cabbage until the edible product is ready for cooking. Fig. 83.— Cabbage root-maggot- a. Larva; b, puparium, dorsal view; c, female fly; d, head of male; e, antenna. All enlarged. (After Riley, U- S. Dept. Agr.) ROOT-MAGGOTS The Cabbage Maggot (Pegomya brassicce Bouche). — The roots of cabbage and related cruciferous crop plants frequently suffer severe injury from the attack of the cabbage maggot (fig. 83). Young plants are most seriously affected, the mag- 131 132 INSECTS INJURIOUS TO VEGETABLES gots eroding the outer surface and boring into the interior of the roots, devouring the tender rootlets and frequently pene- trating into the lower portion of the stalk. This insect, known also as radish maggot, is an imported pest. It does serious injury throughout the northern tier of States and Canada, at- tacking all forms of crucifers. It is the cause of more or less loss to these crops each year. Since 1902 it has not only been exceedingly destructive, but has increased in injuriousness from year to year. Frequently entire crops over considerable areas are completely destroyed. Two or three generations of this maggot are indicated where it has been observed. REMEDIES The remedies prescribed for the seed-corn maggot are ap- plicable. In addition there are certain preventive and other measures for its destruction that have been found successful, their use being justified by the great value of cabbage plants. Carbolic-acid emulsion, prepared as prescribed on page 37, and diluted about 35 times, is applicable when this maggot oc- curs on radish. Hand-picking, although laborious, has the merit of effective- ness, and is useful on cabbage, although not practicable on radish and similar crops. It consists in pulling up the young plants, examining the roots for eggs and maggots, and either destroying the eggs and maggots by crushing with the hand or by washing the roots in a strong solution of soap and then replanting. In most cases the plants show no ill effects from this treatment after two or three weeks have elapsed. Methods of cultivation. — Comparatively little can be expected from various farming methods which are safeguards against other insects. Keeping the soil well hilled around the cabbage plants develops more roots, thus affording more food for the maggots and leaving enough roots to strengthen the plant itself. Crop rotation should be followed with any plants other than INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS 1 33 crucifers or onions. With these latter it is inadvisable, as the same atmospheric or other conditions which induce injury by the cabbage maggot seem to operate in increasing the numbers of the onion pest, which has a similar distribution. Fall plowing is advisable and cabbage stumps should be removed and de- stroyed, especially early in the season. Bisulphid of carbon treatment. — In case tarred paper cards, which will next be described, or other preventive methods are not employed, bisulphid of carbon may be used. It should be Fig 84.— Bisulphid of carbon injector in use Fig. 85.— Tarred paper card in outline. One^half size. (After Coff.) applied below the root system with a special injector or syringe, 1 taking care that the application is not made directly to the plants, as it is likely to kill them. A hole is made a little distance (3 or 4 inches) from the plant, and the injector in- serted at an angle, as shown in figure 84. After injecting the liquid the instrument should be withdrawn and the hole closed by packing with the foot. From a teaspoonful to a tablespoon- ful to each young plant, and a single application, is generally sufficient. Tarred paper cards. — The use of disks or pads of tarred paper 1 The McGowen injector, no longer for sale, has proved very successful. 134 INSECTS INJURIOUS TO VEGETABLES for the protection of cabbage against the oviposition of the fly was perfected in 1889 by Mr. W. H. Goff. The cards are cut in hexagonal form (fig. 85), in order to economize material, and a thin grade of tarred paper is used, as y*^-^. the cards made from it are more readily placed L. — about the plant without being torn. The blade of the tool, which can be made by a blacksmith, is formed from a band of steel, bent in the form of a half hexagon, and then taking an acute angle, reaches nearly to the center, as shown in figure 86. The part making the star-shaped cut is formed from a separate piece of steel, so attached to the handle as to make a close joint with the blade. The latter is beveled from the outside all around, so that by removing the part making the star-shaped cut the edge may be ground on a grindstone. It is important that the angles in the blade be perfect, and that its out- line represent an exact half hexagon. To use the tool, place the tarred paper on the p^, 86^— Tool for en d of a section of wood and first cut the lower A U bcmt § one a fourth ec ^ e * nto notcnes > as indicated in figure 87, using size. (After Goff.) only one angle of the tool. Commence at the left side, and place the blade as indicated by the dotted lines, and strike at the end of the handle with a light mallet, and a complete card is made. Continue in this manner across the Fig. 87.— Showing how tool is used, dotted line indicating position of edge of tool. (After Goff) INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS 1 35 paper. The first cut of every alternate course will make an imperfect carcl, and the last cut in any course may be imperfect, but the other cuts will make perfect cards if the tool is correctly made and properly used. The cards should be placed about the plants at the time of transplanting. To place the card, bend it slightly, to open the slit, then slip it on the center, the stem entering the slit, after which spread the card out flat, and press the points formed by the star-shaped cut snugly around the stem. A Wisconsin grower protected 7,000 plants and secured a splendid crop, while unprotected plants nearby would have been a complete failure if the maggots had not been picked off by hand. Others have reported similar success. One lost only 25 plants out of 10,000 to 15,000 that he protected with the cards, where ordinarily he would have lost from 75 to 90 per cent, of the crop. The tarred cards are applicable to cabbage and cauliflower only, but it is claimed by those who have employed them that they are cheaper, more practicable, and more efficient than any- thing as yet devised for preventing the ravages of the cabbage maggot. Success in using them is dependent upon their being properly applied, to fit tightly, so that the fly is unable to obtain access to the stem for the deposition of her eggs. Cards must be renewed and their use continued for each maggot year to be effective. Coverings and hellebore. — Some success has also been attained by covering young plants in seed-beds with netting and by ap- plying hellebore about the roots. The Seed-corn Maggot (Pegomya fusciceps Zett.). — This species, previously considered on page 106 on bean and pea insects has been identified with attack to cabbage, turnip and radish on numerous occasions and in many localities. When occurring on such plants it should be treated in about the same method as the cabbage maggot. I36 INSECTS INJURIOUS TO VEGETABLES CABBAGE WORMS The Imported Cabbage Worm (Pontia rapce Linn.). — This is the worst of all cabbage pests and one of the most important of all truck insects. It is altogether too well known through- -' d Fig. 88.— Pontia rapae. a, Female butterfly; b, egg; c, larva on cabbage leaf; d, sus- pended chrysalis, a, c, d, Slightly enlarged; b, more enlarged. (Author's illustration, U.S.Dept. Agr.) out North America and Europe, and the white butter- fly is quite generally recognized as its parent. The cater- pillar is velvety green and measures, when full grown, about an inch and a quarter, presenting the appearance shown in figure 88, c. The butterfly has a wing expanse of nearly two inches, and is white, marked with black near the tips of the fore-wings. The female (a) has two conspicuous black spots on each fore-wing, the male has only one. This cabbage worm is the bane of every cabbage-grower, and the dread of every INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS 1 37 careful cook and housewife. It begins work early in the season, when the principal damage is usually accomplished, and after riddling the outer leaves, attacks the more tender inner leaves as they form, frequently secreting itself in the heads, which are made most unsightly by its excrement. This species was first observed in the United States in 1865 and in about a score of years it had invaded nearly every state and territory in our domains. All cruciferous crops, but particularly cabbage and cauli- flower, are attacked, as are also nasturtium, mignonette and some allied plants. The butterflies are on the wing from early morn till dusk. As early as March they can be seen flying about cabbage fields and they continue until after severe frosts. The observed egg period is from 4 to 8 days. The larva eats voraciously and grows with rapidity, attaining full growth in from 10 to 14 days after hatching. The summer-time chrysalis period is from 7 to 14 days, but the last chrysalides remain undeveloped until the following spring. The life cycle has been traced from between 22 days to five weeks. Even in New England this species is credited with being triple brooded, but in the District of Columbia and vicinity there must be one or more additional generations, and there is a possibility of still more in the extreme South. A natural enemy of this species, Pteromalus puparum, is shown in figure 89, and a "worm" parasitized by Apanteles glomeratus is illustrated by figure 90. REMEDIES In treating this species it should be borne in mind that other "worms" and pests are more often present than otherwise. Arsenicals. — The best remedy is Paris green applied, prefer- ably as a spray, at the rate of about one pound of poison to 150 gallons or less of water, and it should be used when plants are first set out, to insure its reaching the young "worms" be- 138 INSECTS INJURIOUS TO VEGETABLES fore they have burrowed far into the heads. Other applications should follow frequently, as required, and can be made with safety until the heads are about half formed, and even later, as the poison, under ordinary circumstances, disappears from the plants two or three weeks after being applied. Bran mash is, according to the testimony of some, successful against cabbage worms. It is prepared in the same manner as for cutworms and grasshoppers. See page 55. Kerosene emulsion is not as efficient as arsenicals, because Fig. 89.— Pteromalus puparum. Female Highly magnified. (Author's illustra- tion, U. S. Dept. Agr.) Fig. 90.— Parasitized cabbage worm (Pontia rapce), showing cocoon mass of Apanteles glomeratus below. (Author, U. S. Dept. Agr.) it is necessary for this spray to come into direct contact with the "worms." Pyrethrum has the advantage of not being poisonous to humans, but is said by some cabbage growers to discolor the leaves, and if its use is not continued at frequent intervals the "worms" recover. It is more expensive than remedies that have been mentioned. Hot water at a temperature of about 130 F. does practically no harm to plants and destroys all insects with which it comes in contact. Clean cultivation and trap crops. — If united effort in clean farming could be secured, together with the use of arsenicals, the losses due to the ravages of this and other leaf-feeding cabbage pests might be largely averted. The practice of leaving INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS I39 cabbage stalks in the field after the crop has been secured is reprehensible. Remnants should be destroyed, with the exception of a few left at intervals through a field as traps for the females for the deposition of their eggs. These plants should be freely poisoned with arsenicals, so that the last generation will not develop. The Southern Cabbage Butterfly (Pontia protodice Boisd.).— Before the advent of the imported cabbage butterfly, the present species was the occasion of considerable injury, particularly [HUH Fig. 91.— Southern cabbage butterfly worm. (After Riley) Fig. 92.— Potherb butterfly. Adult above, larva below. (After Harris) southward. Of late it has disappeared in many regions, but occasionally makes its reappearance for a limited period. In many respects it resembles the preceding, and the male as it is seen flitting lazily through cabbage fields and gardens would * never be recognized as" distinct from the more injurious form. The "worm" (fig. 91) varies from pale to dark blue or green, is striped with yellow and covered with black spots bearing black hairs. Remedies. — The treatment is the same as for the preceding. The Potherb Butterfly (Pontia napi Linn.).— This butter- fly is found in the more northern and eastern portions of North America, and is distinguished from others attacking cole crops by its nearly uniform white wings without spots. The larva (fig. 92) is uniform pale green, and resembles the cab- 140 INSECTS INJURIOUS TO VEGETABLES bage leaves on which it feeds. It devours the pulp on the lower surface, often leaving the veins intact. This species has evidently been decimated in the same man- ner as the southern cabbage butterfly by the foreign invader, Pontia rapes, and is now seldom found save on wild plants. Remedies are the same as for the imported cabbage butterfly. The Cross-striped Cabbage Worm (Evergestis rimo salts Guen.). — Thus far have been considered only the "worms" produced by butterflies. The species figured and those which Fig, 93.— Cross-striped cabbage worm, a, Moth; b, egg mass; c, sculpture of egg; d 'worm ' ; e, cocoon, a, d, e, Twice natural size, b, c, more enlarged. (Author's illustration, U. S. Dept. Agr.) follow are all the progeny of moths. This "worm" injures cab- bage and its varieties in nearly the same manner as does the im- ported cabbage worm, attacking the heads and digging deeply into, and eating out, the hearts. While plants are tender this destroys them for the market or table. This species is as a rule less injurious to other crucifers (fig. 93). Remedies. — The remedies advised as best for the imported cabbage worm are equally applicable to this species. The Common Cabbage Looper (Autographa brassicce Riley). — Late cabbage particularly southward is much subject to injury by the looper or cabbage "plusia" which is, next to the imported INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS I4I cabbage worm and the harlequin bug, our most important insect enemy of cruciferous crops. It is unusually voracious, devel- oping rapidly, but is kept under partial control by natural in- fluences, and therefore subject to extreme fluctuation in num- bers, doing great damage for one or more seasons in some localities, and remaining absent from them for a number of succeeding years. The insect derives its name from the peculiar habit of its larva of "looping" like a measuring worm, due to the lack of legs on the third and fourth joints of the abdomen. The moth which produces it is shown in figure 9, a. The "looper" is at first a pale-green, fragile-looking creature, and varies in color when mature, being strongly marked with white lines, shown in figure 9, c. It constructs for pupation a white, gauzy cocoon, d, which is usually attached to the broad surface of a leaf. The cabbage looper is well distributed throughout that part of the United States lying east of the Rocky Mountains, and is more destructive in the South than in the northern States. It is most troublesome to cabbage, but affects all crucifers and at times does great injury to peas, beets, celery and lettuce, and feeds also on tomato, potato and less frequently on asparagus and clover. It sometimes does damage to carnation, mignonette, and German ivy in greenhouses. The species is apparently three-brooded on Long Island and in the District of Columbia, and hibernation takes place chiefly in the pupal stage. Few individuals survive the winter north- ward, but the propagation of the species is so rapid that by the time autumn is reached great numbers of loopers are produced which do much damage to crops in cultivation at this time. This insect is very susceptible to diseases and to parasitism. A par- asitized looper is shown by figure 94. Methods of Control employed for other cabbage worms are useful against loopers. Remedial measures should be continued with persistency at frequent intervals in order to insure sue- 142 INSECTS INJURIOUS TO VEGETABLES cess, and arsenicals should be applied when possible to the lower surface of the outer leaves to destroy all the insects. If the first generations could be killed off there would be less difficulty in keeping the insect in subjection. Paris green mixed with lime or other diluent has been used dry with some success, but is less efficient than for the imported cabbage worm. Dry ap- plications do not reach the lower surface, hence a spray is preferable. The larger loopers eat through the leaves, but when they find anything distasteful they cease feeding and search for tissue that has not been poisoned. After rainfall eggs hatch and the poison having been washed away the larvae continue feeding. Sirrine obtains good results with resin-lime mixture. It requires about two hours to make this mixture, and considerable Fig. 94.— Cabbage looper parasitized by Copidosoma Vuncatelhx Slightly enlarged (After Riley, U. S. Dept. Agr J care is necessary in its preparation; but when crops are grown on a large scale it might pay to use this remedy. It has the advantage of being more adhesive than a Paris green spray, remaining on the under surfaces as well as upper leaves and requiring two or three heavy rains to remove all of it, even on the exposed portions of leaves. Arsenate of lead has similai adhesiveness, and as it has given good results in experiments on a small scale it should receive further tests. The Imported Cabbage Webworm (Hellula undalis Fab.). — • As if the cabbage-grower did not have enough "worms" with which to contend a new species has recently appeared in the South, and there is now the threatened danger of its introduc- tion farther north in the same manner as has happened in the INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS I43 case of the cabbage looper and harlequin cabbage bug. The species under consideration, the imported cabbage webworm, should it increase in destructiveness and enlarge its area, bids fair to become a troublesome species, as it is difficult to treat. The moth (fig. 95, a) is gray, with the fore-wings mottled with black, white and brown. The expanse of wing is about Fig. 95.— Cabbage webworm. a, Mature moth; b larva, lateral view; c, larva, dorsal view; d. pupa All three times natural size. (Author's illustration, U. S. Dept. Agr-) five-eighths of an inch. The mature larva (fig. 95, b, c) is a little more than half an inch long, in color dull yellowish-gray, striped with broad, brownish-purple longitudinal bands. The moth is described as laying her eggs in the "bud" of cabbage, or turnip, and the larva soon after hatching spins a web over itself, leaving a hole for egress. From the protection afforded by this domicile the larva feeds, retiring into the web when its hunger is appeased. When larvae are particularly numerous three or four days suffice for the destruction of a turnip or cab- bage patch, the plants rotting, or in the case of turnip failing to develop roots, and this with their excrement which adheres 144 INSECTS INJURIOUS TO VEGETABLES to the plants, forms a more or less perfect place of concealment for them. Remedial Measures. — A spray of Paris green applied as soon as the larva hatches serves in great measure to control it. Clean cultural methods should be persistently practiced, and every bit of refuse material, particularly cabbage stalks and weeds, should be raked up into piles and set afire by adding, if necessary, dry straw to aid in their ignition. Kerosene emulsion, properly prepared and applied sufficiently often to insure a permanent odor, should be effective in preventing egg laying and will also destroy other insects with which it may come in contact. The Diamond-back Moth (Plutella maculipennis Curtis). — One of the minor enemies of cabbage is the larva of the imported diamond-back moth or "cabbage plutella." It is smaller than any of the preceding, and as a rule its injuries are much less conspicuous. Occasionally, however, it becomes sufficiently numerous as to be quite troublesome. Its minute active cater- pillar may be found on cabbage everywhere, and in this stage as well as in pupa, when it rests in a beautiful white, lace-like cocoon attached to the surface of cabbage leaves, it is familiar to observing persons. Attack is usually confined to the outer leaves, the larva feeding generally on the lower surface and not eating through, as with the larger looper and some other worms. At times, however, leaves are riddled with holes and much of their substance devoured. The moth (fig. 96, /) is gray and distinguished by the black- marked fore-wing. The wing expanse is about three-fifths of an inch. This insect is found during winter on old cabbage stalks, hibernation taking place normally as pupa, although adults also occur as late as December. Two or three genera- tions are produced in the more northern States, and farther south four or five broods occur during a season. In the extreme South the insect occurs throughout the year. INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS I45 Remedies. — The simpler cabbage worm remedies are suffi- cient in ordinary cases. Pyrethrum is valuable as is also kero- sene emulsion, but Paris green, unless applied as an under- spray, which is difficult with most cruciferous crops, is reported not so effective. Cutworms will attack cabbage, turnip, and similar plants when available, and there are a number of caterpillars, other than those which have been considered, which do great damage Fig. 96.— Diamond-back moth, a, Larva; b, c, segments of same; d, pupa; e, pupa in cocoon; /. h, moth; g, wings of dark form of moth; 1, last segment of pupa. All en- larged. (After Riley, U. S. Dept. Agr.) to these crops. When cutworms become abundant late in the season, plants are damaged in the same manner as by the imported cabbage worm, by eating the more tender portions and penetrating into the hearts. Severe injury is often reported, e. g., in one garden only 30 plants out of 600 escaped, while it is not uncommon to lose half or more of the plants early in the spring. The fall army worm, salt-marsh caterpillar and "woolly bears" frequently attack* cole crops, and the first mentioned when numerous does damage of great seriousness. The zebra and clover caterpillars appear to favor these crops among others grown in gardens, and the garden webworm also affects them. These species are treated in preceding chapters. 146 INSECTS INJURIOUS TO VEGETABLES FLEA-BEETLES AND LEAF-BEETLES An unusual number of flea-beetles are reckoned among enemies of cruciferous crops. No less than seven species (of Phyllotreta) are more or less attached to this class of plants and although like other flea-beetles they are as a rule only periodically troublesome, they are in their abundant seasons foes of. no little importance. The characteristics of flea-beetles have been described on page 63. The cabbage-feeding forms are mostly quite minute, none measuring more than an eighth of an inch. The Striped Turnip Flea-beetle (Phyllotreta vittata Fab.). — The commonest and most destructive flea-beetle living on cruciferous crops is the species above mentioned. It is found throughout the warmer months, and attacks most crucifers, cul- tivated and wild. As it is sub- ject to great fluctuation in num- bers, it cannot be compared to the imported cabbage looper or harlequin bug, yet it is capable of severe injuries and crucifer- ous crops are seldom free from it within its range, which is extensive. The beetle (fig. 97, b) is polished black in color, and each wing-cover is ornamented with a broad, wavy band of pale yellow. This species is indigenous to the Atlantic region, where it is most abundant, but has been diffused by commerce, until now it is found in most States and Territories from Maine to the Gulf and Pacific States. Remedies. — When cabbage and other crucifers are treated with arsenicals for "worms" no further remedy is necessary Fig. 97-— Striped turnip beetle, a, larva b, beetle. (Riley, U. S. Dept. Agr.) INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS 1 47 for flea-beetles. It adds to the effectiveness of Paris green, however, to use Bordeaux mixture as a diluent, as the latter in addition to being a fungicide is a powerful deterrent of Fig. 98.— Water-cress leaf-beetle (Phasdon aeruginosa), a. Adult; b, larva; d. pupa Enlarged six times. (Author's illustration, U. S. Dept. Agr.) flea-beetles. See page 65 on remedies for leaf-beetles and flea-beetles. The Water-cress Leaf-beetle (Phcedon ceruginosa Suffr.) has been reported injurious to water-cress since 1903. It is a small, metallic blackish beetle (fig. 98) and with the water-cress sowbug (figured on page 4) is a pest on the plant from which they have both re ceived their English name. 1 The Western Cabbage Flea-beetle (Phyl- lotreta pusilla Horn.). — In some of the western States not yet inhabited by either of the preceding there is a smaller, dark- colored flea-beetle which sometimes does great damage to crucifers and many other crops. This flea-beetle is of a uniform deep Fi 99.— western cab- polished olive-green color, and the surface ba s e flea-beetle. Much , , T , enlarged. (After Riley, is irregularly punctate. It measures about u. S. Dept. Agr.) seven-hundredths of an inch in length. It ranges from the Dakotas to Mexico, and westward to Southern California and is often found in great numbers. 1 Information concerning both species is furnished in Bui. No. 66, Pt. II, Bu. Entom., U. S. Dept. Agr. 148 INSECTS INJURIOUS TO VEGETABLES Remedies. — Owing to the peculiarity of this species of con- gregating in immense numbers and doing great damage in a short time, immediate steps for its suppression must be taken. Remedies advised for the striped turnip flea-beetle are applicable. PLANT-BUGS AND APHIDES The Harlequin Cabbage Bug (Murgantia histrionica Hahn.). — From southern New York and Ohio southward, late cabbage and other cole crops sometimes suffer severely from a gayly colored plant-bug variously known as the calico back, fire bug, Fig. 100.— Harlequin cabbage bug- a. Young; b, half grown; c, d, egg cluster; e, same from above; /, g, adult, c, f, g, Natural size; a, b, slightly enlarged; d, e more en- larged. (After Riley.) and terrapin bug, as well as harlequin cabbage bug. It is the most destructive cabbage pest of the South, and second only to the imported cabbage worm as an enemy to the cole crops of our country. It is a native of Mexico and Central America and since its discovery in Texas in 1866 its dissemination north- ward and eastward has been rapid, until at one time it threatened to overrun southern portions of New York and New England, Ohio and States farther westward. The harlequin-like ornamen- tation of the insect is shown in figure 100, /. the dark portions are shining black or dark blue and the lighter portions INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS I49 bright yellow or red. The eggs (d) are beautiful objects, looking like miniature white barrels bound with black hoops, and with black spots set in the proper place for bung-holes. This insect accomplishes its work of destruction by sucking the sap from leaves and veins of cabbage and other crucifers, the affected leaves wilting, withering and dying as if fire- swept — whence the name "fire bug." Half a dozen mature insects suffice to destroy a small plant in a day. This is a pest which, if permitted to have its own way, is almost certain to destroy a portion, and if sufficiently numerous, all of the fields which it infests, and the writer has seen in the vicinity of the District of Columbia, in Maryland and Virginia many fields in successive years from which not a single good cabbage could be cut, and has observed equal injury to horseradish and some other crucifers. Toward the end of the season and in early winter the mature bugs are still afield, seeming loath to seek shelter from the cold. When cruciferous crops have become exhausted they attack almost any form of vegetation. Preventive and Remedial Measures. — The difficulty of de- stroying this insect with contact poisons such as kerosene- soap emulsion, which are practically inert against the adults and only partially effective on the youngest nymphs, necessi- tates the use of preventives to compass this end. The most important is clean farm practice. The practice of leaving cabbage stalks and other cruciferous plants in the field late in autumn and early winter, or of allowing cruciferous weeds to grow up, or, in fact, allowing any sort of debris to accumulate, serves to protract the life of this insect by affording it food or quarters for protection against the cold. It is inadvisable to plant crucifers in the vicinity of outhouses and barns, as the bugs use such places for passing the winter. Some of the insect's food plants may be left, after cropping, at intervals throughout fields to attract the bugs in the fall, and here they may be killed with crude kerosene, by mechanical 15° INSECTS INJURIOUS TO VEGETABLES methods, or piles of rubbish may be left to attract them where they can be burned. The best remedy, however, and one that should be put into operation by every southern cabbage grower, is the planting of an early crop of mustard, radish, rape, or kale as a lure for the first appearing bugs. Overwintered bugs appear from March to May. They appear to prefer for the first deposition of their eggs the plants that have been mentioned, though cabbage may be available. On these the insects are killed by kerosene or by hand, as, for example, by capture with a hand net, or by burning the traps when these are of no value as Fig. 101.— False chinch-bug. a, Leaf showing punctures; b, last nymph stage. c, adult, a, Natural size; b, c much enlarged. (After Riley) food. If the first generation is generally done away with, few insects fly from other quarters, and injury is largely prevented for an entire season. The False Chinch-bug (Nysius angustatus Uhl.). — The false chinch-bug, although a general feeder, appears to be somewhat more attached to turnip, cabbage and similar crops, but also injuriously affects potato, beets, lettuce, the vine, apple, grass and strawberry. It derives its name of false chinch-bug from its being frequently mistaken for the true chinch-bug, to which indeed it is related. The adult is grayish brown and of the appearance shown in figure 101, c. The hemelytra or wing- covers are more or less transparent. The length is about one-eighth of an inch. In distribution it extends from New INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS 15I Hampshire to the Gulf, and westward to the Pacific States. At a of figure 101 is represented the appearance of a leaf of potato showing the minute, rusty circular specks where the beak of this bug has been inserted. The false chinch-bug frequently occurs in such numbers as to attract general atten- tion. The bugs crowd together on a plant in the same manner as do the chinch-bugs on corn, and the harlequin bugs on cabbage; and as they also feed by suction, they soon exhaust a plant by depriving it. of its juices, which in time causes it to wilt and die. This is an active bug, and when alarmed on warm days, the winged individuals readily take to flight, arising in swarms. It. is subject to the same atmospheric influences as the chinch-bug, and damp, rainy weather is unfavorable to its development. It has been surmised that there are two or three generations a year and that the insect hibernates mainly in the perfect state under rubbish of different sorts. 1 Remedies. — The best way of controlling this bug consists in the keeping down of purslane, a favorite food plant, the careful cleaning up and burning of all trash before winter, the collection of the bugs when they occur in numbers in pans or pails filled with water and a thin scum of kerosene, and the free use of 10 per cent, kerosene emulsion. The Cabbage Aphis (Aphis brassicce Linn.). — In seasons when atmospheric conditions favor its development this insect, which is also known as the "cabbage louse", 2 can be exceedingly troublesome ; indeed, were it not for its susceptibility to many natural enemies, it would always be a pest of the highest im- portance in localities adapted for its increase. This species affords a most excellent example of the usefulness of natural enemies. A vast number of insects that prey on aphides 1 A related bug (Nysius minutus Uhl.) very nearly resembles the preceding in appearance and in habits, and may be controlled by the same methods. 2 A similar aphis (Rh op ah sip hum dianthi Schr.) , with somewhat similar habits, is also very injurious to cole crops and may be controlled by about the same means. 152 INSECTS INJURIOUS TO VEGETABLES attack it, and in many regions hold it down to moderate num- bers save in exceptional seasons. In dry, warm weather the insect enemies are most active, while in cooler dry weather they are less efficient and then the plant-lice frequently gain the ascendency, to the detriment of the cabbage crop. Its first appearance is usually noticed in June, and it remains Fig 102.— Cabbage aphis. 0, So-called '' male " ; b, wingless viviparous female. Greatly enlarged; natural size indicated by small outlines. (After Curtis) until quite cold weather. In the District of Columbia the writer has observed this species active as late as the middle of Decem- ber, mostly, however, at this time, in the hearts of cabbage, where the aphides had crawled for protection. Practically the same or related insect enemies of the pea aphis which have been mentioned in preceding pages attack the cabbage aphis. Remedies. — The cabbage aphis can be controlled by much the same remedies as advised for the melon aphis (page 165), the free use of pyrethrum applied by a bellows at any stage of the growth of the cabbage or other plant; or by kerosene emulsion, which is of value when the plants are young and until the heads begin to complete their growth. Soap solutions may be used if preferred, those known as whale-oil soap, made of fish oil, and potash soaps, made from caustic potash, being the best. A strong stream of water directed upon the plants from a INSECTS INJURIOUS TO CABBAGE AND OTHER CROPS 1 53 syringe, hose or spraying machine is often of service in check- ing the work of this insect. Application of remedies should be made upon the first appearance of the insects. Clean cultural practice should be observed. MAGGOT LEAF-MINERS The leaves of cabbage, turnip, radish and other crucifers are subject to the attack of minute maggots which manifest their presence by whitish blotches of larger or less extent, Fig. 103.— Imported turnip leaf-miner, a. Larva; b, puparium; c, adult; d> antenna of fly; e, work in radish leaf. Natural size; all. others enlarged. (Reengraved after Coquil- lett, U. S. Dept. Agr.) termed mines. If a leaf be held toward the light the maggot can be seen at work between the surfaces. Four species of leaf-miners commonly affect crucifers. These insects are not as a rule very destructive, but they kill off leaves here and there, thus weakening the plants, and rendering them more liable to disease and to injury by other insects. Sometimes, however, they destroy whole plants. Attack is more apparent on young plants and is easily recognized. One of the commonest 154 INSECTS INJURIOUS TO VEGETABLES of these insects is the imported turnip leaf-miner (Scaptomyza flaveola Meig.) shown in figure 103. Remedies. — These leaf-miners are not very injurious to large interests. In small gardens they can be controlled by clipping the infested leaves as soon as the mines appear and destroying them. Fig. 103x.— A young cabbage looper, highly magnified. (Author, U- S. D#pt. Agr,; CHAPTER X INSECTS INJURIOUS TO CUCUMBER, MELON AND RELATED PLANTS If we except cabbage no vegetable crops suffer more from the ravages of insects than do the cucurbits — squashes, cucum- bers and melons. They are subject to attack from the time the seed is planted and after it has sprouted until the fruit is ripe for market. Injury is not effected by so many species of insects, as in the case of cabbage, less than a score of distinct forms being commonly identified with damage, but of these nearly a dozen are highly injurious, and half as many from their extensive distribution and destructiveness are of the greatest importance. It is no uncommon sight to see four or five distinct species on a single plant, and several others in the same field. The seeds are attacked in the ground by a maggot which eats into them and prevents germination. After the seed has sprouted the plant becomes the prey of the striped cucumber beetle, the most troublesome of all cucurbit-feeding insects. Such plants as are so fortunate as not to be attacked by this beetle, cutworms and some few other "general feeders" may next encounter the squash bug and then the squash-vine borer. The latter severs the vine or injures it so that it wilts and dies. It is next to impossible in many portions of the United States to find cucurbits that are wholly free from the melon aphis which feeds by absorbing vegetable juices by suction. After the plants have escaped the insects above enumerated 155 156 INSECTS INJURIOUS TO VEGETABLES they are still liable to injury from others and more especially from the pickle worm and melon caterpillar which bore into the fruit and render it unfit for market. Cucurbits grown under glass are subject to injury by four important pests : the striped cucumber beetle, melon aphis, greenhouse white fly and onion thrips. The Striped Cucumber Beetle (Diabrotica vittata Fab.). — With the first appearance of cucumber, squash and melon plants 9> * d e Fig- 104— Striped cucumber beetle, a, Beetle; b, larva; c, pupa; d, egg; e, sculp- ture of egg. (Author's illustration, U. S. Dept Agr.) early in the season, often before they are above ground, they are attacked by the striped cucumbar beetle, often called the "striped bug" and "melon bug." The beetle measures about two-fifths of an inch in length. Its color is yellow above, with black head and elytra longi- tudinally striped, as figured (fig. 104). The egg is lemon yel- low and of the appearance shown, where the sculpture is also illustrated. The larva is a slender, white, worm-like creature, with brown head, anal and thoracic plate. When mature it measures about three-tenths of an inch, this being about ten times its width. The species is indigenous and inhabits the entire eastern United States. INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. I57 The principal injury is effected by the hibernated beetles devouring the tender plants before they have fairly started. The beetles are also destructive to older plants, by eating the leaves and gnawing the rind of stems and the fruit, while the larvae cause injury through their pernicious work at the roots. Still another form of mischief is due to the beetles in acting as carriers of the insidious bacterial disease "cucurbit wilt." The beetles usually make their appearance in April or May, feed on flowers or other vegetation, and when cucurbits are set out attack and injure them as previously described. Eggs are deposited soon after the host plants are well above ground, and on leaf-stalks just below the surface of the ground. The larval period is passed in the earth, about the bases of the stalks, and larvae may be found within the stems under as well as above ground, and there is an active stage of about a month's duration in which the larvse working in numbers have Fig- 105- Ceiatoria diabroticx. Fiypara- , .... , site of cucumber beetles. Much enlarged. ample time for injuring the (Author's illustration, U. S. Dept.Agr.) vines. Toward the end of the season the beetles congregate under stems, prostrate plants and withered leaves of cucurbits, as many as sixty individuals assembling about a single plant, and later they seek other places of shelter. Hibernation near Washington evidently begins during the first cold nights of October. Great numbers of this insect are destroyed by a dipterous parasite, somewhat resembling a small house fly, and known as Celatoria diabroticce Shim. (fig. 105), which develops as a maggot within the beetle, which it destroys when it issues. 158 INSECTS INJURIOUS TO VEGETABLES REMEDIES How to control this cucumber beetle is one of the hardest propositions to solve. Poisons will destroy the beetles when they occur in moderate numbers, but are not entirely efficacious when they are most abundant, hence recourse must be had to preventives and repellents, and to farm practice. Coverings. — To prevent injury to young plants coverings are used. A cheap frame may be made by cutting a barrel hoop in two so as to form two semicircles, which are placed at right angles to each other, and the lower ends inserted in the ground with the curve uppermost. This is then covered with gauze or similar material, held in place so to prevent the beetles work- ing through or under it. Early planting, etc. — Where no covering is used it is advisable to start plants under glass, or to plant the earliest varieties and set them out as soon as possible so as to have the plant well established before the appearance of the beetles. The setting out of late varieties should be postponed until after the first appearing beetles have laid their eggs and dispersed. A cer- tain degree of relief follows the planting of an excess of seed so as to distribute attack. After the first danger is passed the hills are thinned out to the desired number. Clean farming and trap plants. — Much injury from this and other cucurbit pests would be prevented by more attention to clean methods of cultivation. As soon as a crop is harvested the vines should be covered with straw or other inflammable material and burned, and certain plants should be left here and there throughout the fields, so that such insects as may not be reached by the fire will concentrate on them where they can be destroyed with strong kerosene emulsion or Paris green. As traps for the last generation it would be wise to plant late or to use later varieties. Some exemption may be attained by growing beans with cucumbers in alternate rows. The beans are planted before the cucumbers and the beetles congregate INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 1 59 on the beans and, having an abundance of food, do not attack the young cucurbits. Driving, etc. — In some sections "driving" is practiced. Air- slaked lime is dusted over the plants with the wind and the beetles fly before it to the next patch where similar methods have to be employed. Another remedy is to dust the majority of plants with sifted ashes, road dust or plaster, and cover those which are undusted with an arsenical, in the proportion of one-fourth of a pound to about 40 gallons of water. The beetles are thus driven to concentrate on the clean plants, where they are killed by the poison. Refuse tobacco dust sprinkled on the hills when the soil is moist acts as a repellent and as a fertilizer and mulch for the plant. Applications must be renewed when rainfall necessitates. Pyrethrum and other insecticides dusted on the plants are useful, but expensive. Paris green and other arsenicals applied dry as for potato beetles are valuable, but all poisons must be renewed frequently and are not generally to be relied upon when the beetles are exceedingly numerous. In case Bordeaux mixture is used as a protection against fungous diseases, Paris green Should be added, as it necessitates little additional trouble and the mixture will prove more effective than either when used alone. Stimulating growth. — A considerable degree of exemption from injury accrues from the stimulation of a crop by heavy manuring, or the use of mineral fertilizers and frequent cultivation. The Twelve-spotted Cucumber Beetle (Diabrotica 12-punctata 01.). — This beetle will be considered at length in the dis- cussion of insects affecting sweet corn. In exceptional sea- sons it does nearly as. much injury locally to cucurbits as the striped cucumber beetle, with which it is nearly always asso- ciated. At such times, the same remedies should be employed. i6o INSECTS INJURIOUS TO VEGETABLES The SquasTi Ladybird (Epilachna bore alls Fab.). — The leaves of squash, pumpkin and the other cucurbits are often found showing numerous wilted and eroded circular or semi- circular spaces. The source is not far to seek, and can readily be traced to the squash ladybird and its larva. This insect is of the characteristic hemispherical ladybird form. It is ochra- ceous in color, marked with rounded black spots, as shown in figure 1 06, c. This is one of our largest ladybirds, measuring about one-third of an inch. The larva is yellow and covered a k ° Fig. 106.— Squash ladybird, a, Larva; b, pupa; c, beetle; d, egg; e, surface of same. a, b, c. Three times natural size; d, four times; e, highly magnified. (Author's illus- tration, U. S. Dept. Agr.) with spines arranged in six rows except on the first thoracic segment, where there are four (a). This is an indigene, ranging from South America to Maine and Canada. It is essentially an eastern form, occurring abundantly along the Atlantic seaboard. The singular habit of the larva and beetle of feeding within a circumscribed space, as previously noted, is evidently char- acteristic of this genus of ladybirds. It first marks out a circle, or if it is feeding on the edge of a leaf a more or less complete semicircle, thus enclosing a portion within which it feeds. The larva lives on the lower and the beetles on the upper surface, but the latter may often be found on the under INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. l6l side, and devour all parts except the veins and late in the season sometimes eat the rind of the fruit. The beetle hiber- nates under convenient shelter and appears abroad in May or June according to season and locality. A single generation has been observed. Remedies. — Remedial measures adopted for other cucurbit pests will effect the destruction of this ladybird. Its habit of feeding exposed on the leaves renders it vulnerable to poison- ous applications, and of these the arsenites, dry or in solution, are best. Hand-picking the beetles and egg masses is the only measure necessary under usual circumstances. Fig. 107.— Work of squash ladybird on a squash leaf. Natural size (Author's illustration, U S Dept. Agr.) The Squash Bug (Anasa tristis DeG.). — Of all insects which infest squash and pumpkin the squash bug is the best known. It is also called "stink-bug" from its disagreeable odor, and black or gray squash bug to distinguish it from the so-called "striped bug." In some seasons as, for example, in 1901 and 1902, it even vies with the latter in point of destructiveness. The adult bug, shown twice natural size in figure 108, a, is nearly three-fourths of an inch long, dirty blackish brown above and mottled yellowish beneath. It is more or less harmful during its entire active existence, from the time it leaves the egg till its demise. When numbers attack a plant together it 1 62 INSECTS INJURIOUS TO VEGETABLES is soon exhausted, the tips and leaves wilt and its death fol- lows. It is not alone the extraction of the juices that destroys a plant; whenever the bug "stings" a leaf-stalk, it injects a liquid, which has a poisonous effect, causing the death of the cell tissue about the puncture. It attacks also the leaves and occasionally the fruit, and acts as a transmitter of the "wilt." d e Fig. 108.— Squash bug. a, Adult; b, egg mass; c, d, e, nymphal stages. Enlarged (Author's illustration, U.S. Dept. Agr.) On young plants a few punctures are sometimes sufficient to cause death. The common squash bug is known throughout practically the entire United States, being particularly abundant east of the Rocky Mountains, where it ranges from Maine to the Gulf States and westward to California. Injury may begin soon after the sprouting of the plants, or after they have made considerable growth, and may continue until their death or the departure of the bugs for hibernation. Plants are first attacked by the hibernated bugs. Soon after their appearance, which varies according to temperature and locality from early spring in the South to late in June farther INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 163 north, the insects deposit their eggs, attaching them by an ad- hesive secretion to the leaves in masses of three or four to forty or more. The eggs are metallic brown or bronze and flattened on three sides. They are laid usually on the under side of a leaf, but not infrequently on the upper side, in more or less regular rows (fig. 108, b). They hatch in from eight to thirteen days into small, green and black creatures, which resemble somewhat the mature insects, having proportionately longer legs and antennae. In this period of its existence, the first nymph stage (fig. 108, c), the insect lives in colonies, at Fig. \09. —Trkhopoda pennipes. Tachina fly parasite. Three times natural size (Author's illustration, U- S. Dept. Agr.) first remaining close together upon the leaf near where the eggs were laid, but later congregating about the bases of leaf- stalks or hiding, together with individuals of the more ad- vanced stages, under clods or rubbish or in any convenient retreat, and coming forth toward dusk in search of food. The nymphs cast their skins five times before reaching the mature condition, increasing their growth with each molt. In its last stage the squash bug continues to feed, but with the disappear- ance of its food supply, caused by the dying or clearing away of the crop on which it has fed, it seeks shelter in any convenient rubbish, under boards or stones, dead vegetation, or under 164 INSECTS INJURIOUS TO VEGETABLES bark, or in cracks of barns, and here passes the winter. Hiber- nation in the District of Columbia begins sometime in Sep- tember. This bug is often parasitized by a tachina fly which assists in holding down its numbers. It is Trichopoda pennipes, shown in figure 109, Methods of Control. — This insect is unusually resistant to insecticides. A wash strong enough to kill the mature insect will destroy the vines. This renders it necessary to proceed by hand and cultural methods. A lookout for the bugs should be kept early in the season and these as well as the eggs should be picked off or cut away and destroyed. The eggs are readily seen, and the grower should make a practice at the beginning of each sea- son of going over the vines every few days. Such young as hatch in spite of these precautions may be killed by kerosene emulsion if applied at their first appearance. The bugs may be trapped by placing about the garden boards, shingles, or similar material, which will attract them for shelter. Here they should be destroyed every morning or so during the early season. Protection to cucurbits other than squash, and perhaps pumpkin, can be facilitated by growing these plants with others to serve as trap crops. Attack will thus be cen- tered on a few plants where the insects can be the more readily controlled. A number of the remedies in use against the striped Cucumber beetle and other insect enemies of cucurbits will assist in the control of this species. Among these are the protection of young plants with coverings, the use of repellents, planting an excess of seed to distribute attack, stimulating the plant by manures or other proper fertilizer, and lastly, clean cultural practice. If the vines as soon as the crop is harvested are gathered and burned, many bugs will be destroyed and the number reduced for the ensuing year. INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 165 The Melon Aphis (Aphis gossypii Glov.). — The melon aphis or "louse" may serve as typical of the plant-lice. It is in some seasons one of the most important enemies of melons and some other crops, and is injurious like other aphides by piercing the plants affected with its beak and thus sapping their vitality. It occurs from early spring to late in autumn on cucurbits of all kinds, many other crops and weeds of great variety and in its seasons of abundance, notably following springs that are cool and rainy, it frequently does very serious damage, causing the leaves attacked to curl, shrivel and lose color, inter- fering with the ultimate development of the fruit, if not kill- ing the plants outright. The melon aphis is variable dark green in color and of sluggish habit. 1 The principal stages are illustrated in figure 47. Winter eggs have been found on strawberry and purslane. This species is of unknown but perhaps tropical origin, since it shows a decided preference for, and has done most injury to, plants of a tropical nature, such as cucurbits, cotton and orange. METHODS OF CONTROL The severe losses occasioned by this insect in seasons when it multiplies in unusual numbers could be largely mitigated and, in small areas, almost entirely prevented if the employ- ment of methods of destruction were begun upon its first ap- pearance. First of all, it is necessary to familiarize oneself with the insect and the condition of the plants by which its pres- ence is manifest that measures of control may be instituted before it is too late. In ordinary seasons it is controlled by natural elements and insect enemies alone, and when the weather is unfavorable to the development of the latter the grower should be on the alert. 1 The only other cucurbit louse with which it is apt to be confused is the squash aphis (Nectar ophora cucurbitce Middleton), a much larger species and more uniformly paler green in color. i66 INSECTS INJURIOUS TO VEGETABLES Fig. 110.— Cantaloupe leaves showing curling caused by melon aphis; aphides on lower surface. Slightly reduced. (Author's illustration, U- S. Dept. Agr.) INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 167 Bisulphid of carbon. — In small fields it is customary to cover hills of melons as soon as the insects - make their appearance with a tub or similar receptacle, and evaporate beneath this bisulphid of carbon at the rate of a drachm to a cubic foot or less of space. A tablespoonful serves for ordinary tubs. This does not injure the plant, and if the tub fits tightly to the ground so as to retain the vapor of the bisulphid, the "lic(; ; ' will all be killed. Large growers watch vines carefully, removing and destroying affected plants as soon as noticed to prevent spreading the trouble. Kerosene emulsion and soap solutions. — The melon aphis could be more readily dealt with if it did not feed on the under surface of leaves, and if vines like melons did not grow so closely together as to interlace that spraying by ordinary means is practically impossible. Under-spraying is a necessity, and the sprayer used should be fitted with an up- turned nozzle to secure this effect. Soap solutions, such as whale-oil, fish-oil and potash soap, are not so useful. Clean farming with fall plowing should always be followed, as it is a most valuable measure of prevention of attack by aphides and other insects that are present. As soon as the crop is off remnants should be gathered and burned, and all weeds kept down until the fields are again planted, since, as has been shown, common weeds of the field and garden serve as alter- nate food plants, and are selected as hibernating quarters by the "lice." Pyrethrum applied to the underside of the leaves with a powder bellows is effective, but can not be used with profit on large fields or on plants like squash with large leaves. Remedies that have been indicated as of service in the con- trol of the melon aphis operate against many other insects which are usually present at the same time. Thus the kero- sene and soap solutions kill small squash bugs and act as i68 INSECTS INJURIOUS TO VEGETABLES deterrents of other insects, bisulphid of carbon destroys other aphides and small bugs, as does also pyrethrum. 1 The Squash-vine Borer (Melittia satyriniformis Hbn.). — A most troublesome enemy of squash, pumpkin and other cucur- bits is the squash-vine borer. In many localities it surpasses all other squash insects in point of injuriousness. Damage is due to the white grub-like larvae boring through the stems, causing them to rot at the affected points and become severed from the vine. The presence of the borer in the stem is not apparent at the commencement of the attack, but soon becomes manifest through the presence of the yellowish powdery excre- Fig. 1 1 1.— Squash -vine borer, a, Male moth; £, female, with wings folded in natural position when at rest; c, eggs shown on bit of squash stem; d, full-grown larva, in situ in vine; e, pupa; /, pupal cell. All one-third larger than natural size. (Author's illus- tration, U. S. Dept. Agr.) ment which it forces from its burrow in the stem and which accumulates on the ground beneath, as well as by the sudden wilting and dying down of the leaves. From one to upwards of 145 individuals have been reported taken from a single plant. The larvae work with great rapidity and in a short time in- *A detailed account of the melon aphis, Circ. 80, Bu. Entom., U. S. Dept. Agr., should be consulted for a full consideration of remedies. INSECTS INJURIOUS TO CUCUMBER, MELON, ETC, 169 jure a plant so that no fruit will mature. Injury is most notice- able near the bases of the stems, where in course of time the vine becomes severed from the roots. The parent insect (fig. in, a) is a beautiful clear-winged moth. The fore-wings are lustrous olive-brown, with metallic green reflections, and expand about an inch and a fourth. The Fig. 1 12.— Squash-vine borer, a, Egg- as seen from above; b, same from the side showing- sculpture; c, sculpture of egg greatly enlarged; d, newly-hatched larva; e, half-grown larva; /, head of same from side; g, head of mature larva from above, a, b and d, Much enlarged; e, fandg, less enlarged. (Author's illustration, U. S. Dept. Agr.) abdomen is marked with orange or red, black and bronze, and the hind-legs are fringed with long hairs. The larva is soft, whitish and grub-like. Mature larvae measure about an inch. In the District of Columbia full-grown larvae occur as early as the middle of July and as late as the second week of November. After attaining maturity the larvae enter the earth to the depth of one or two inches and form cocoons (fig. in, /) constructed of silk and coated ex- ternally with fine particles of earth. Observations indicate that this species is practically single-brooded northward; that there is a tendency to two broods in New Jersey; that in the District of Columbia the species is partially double-brooded, and that in the Gulf States it is fully two-brooded. 170 INSECTS INJURIOUS TO VEGETABLES PREVENTIVE AND REMEDIAL MEASURES This borer is exceptionally difficult of control, as ordinary insecticides are of no value after the insect has entered the vines, and repellents are also practically useless. We are, there- fore, dependent upon cultural methods for relief. Knowing that the insect passes the winter in the fields which it has ravaged, it should be superfluous to caution growers not to plant squashes in the same ground in successive years. Early squashes as traps. — Good results are obtained by plant- ing as early as possible a few summer squashes, such as crook- neck and early cymblin, before, and between rows of, the main crop of late varieties. The summer squashes attract the in- sects in numbers, leaving a smaller number to deal with on the main crop. As soon as the early crop is gathered, or earlier if the ground is needed for the main crop, the vines are raked up and burned to destroy all eggs and larvae which they may harbor, and the same treatment is followed after gathering the late varieties. Fall harrozving and spring ploning. — This species can be greatly reduced by lightly harrowing the surface of infested squash fields in the fall so as to bring the cocoons to the surface, where they will be exposed to the elements, and then plowing in the spring to a uniform depth of at least six inches so that the adults will not be able to issue. Cutting out the borers, although laborious, is about the only method open for employment after they have entered the vines. It is best to cut longitudinally, so as not to sever the vine from the root stalk. The location of the borer in the vine can be detected by the accumulation of its yellow excrement at the point where it is working. Other methods. — When vines have attained some length parts of them should be covered with earth so that secondary roots will be sent out in case the main root is injured. Keeping plants INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 171 in good condition, free from disease and other insects, and well nourished, with the assistance of manure or other fertilizer if necessary, will also aid them to withstand attack. If the grower would make certain of securing a good crop in localities where this and other enemies of the squash occur in their most destructive abundance, it will be necessary for protection against this borer to observe most of the precautions specified and, if possible, secure the cooperation of his neighbors. The Pickle Worm (Diaphania nitidalis Cram.). — In the Gulf States and occasionally farther northward two caterpillars are quite injurious to the fruit of melons and other cucurbits. The term "melon worm" is applied to both, as also to the squash borer, since all have the habit of boring into melons ; the last- mentioned, however, is a vine-borer, while the other two, known respectively as the pickle worm and melon caterpillar, feed in their earlier stages in the buds or leaves, and in their later stages in the fruits, which they frequently destroy. They are about equally destructive and work usually by boring directly into the interior, but sometimes eat cavities in the rind. Injury by the pickle worm is seldom noticed until it enters the fruit. The moth (fig. 113, e) is a beautiful creature, quite distinct from any other common species. The upper surface is brown with purplish iridescence. Near the middle of the fore-wings is a somewhat irregular yellowish semitransparent spot, and the inner half or a little more of the lower wings is of the same color. The wing expanse varies from an inch to nearly one and a half inches. Larvae (a, b, c) vary from yellowish to dull brownish green, with a dorsal row of shining round spaces of the same color. The pickle worm is indigenous to America and is probably of tropical origin. It occurs from South America to New York, Michigan and Illinois. It is injurious every year in the Gulf States, instances of damage farther north being only periodical. 1J2 INSECTS INJURIOUS TO VEGETABLES Injury appears to be practically due to the later-appearing gen- erations, and more especially to muskmelons raised for north- ern markets. In September, 1897, fields of cymblins cultivated in Maryland, Virginia and the District of Columbia were badly damaged or totally destroyed by the pickle worm, but in the after years the insect has almost entirely disappeared. The life history and habits of this species have been studied Fig. 1 13.— Pickle worm, c, Larva; b, head and first three segments of larva; c, segment from side; d, pickle showing injury; e, moth; /, cocoon, c, d, e, f, Slightly enlarged; b, c, more enlarged. (After Riley.) by Prof. A. L. Quaintance, in Georgia. Larvae are first noticed there about the middle of June. Eggs are deposited on the flowers, buds, or tender portions of a plant. The larvae first eat out cavities in the leaves or stems, the angle between a leaf and stem being a favorite place of entrance. Frequently they enter flower buds, and have been found by the writer destroying many prospective cymblins in this manner. With the second stage, at least southward, the larvae feed on the young fruit, and as they mature they pass from plant to plant and thus injure for sale much of the fruit affected. They void large INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 1 73 quantities of soft excrement and when several larvae have bored into a fruit it becomes a most disgusting object, quite different from the beautiful moths as they flit about the garden. The length of the life cycle in the South in midsummer is between 24 and 27 days and three generations seem to have been definitely recognized there. When the larvae have finished feeding they crawl out from the infested fruit and transform to pupae within the fold of a leaf or under any sort of debris on the ground. Methods of Control. — The methods that have been ad- vised as most valuable against the striped cucumber beetle and other species, more particularly clean farming, fall plowing and rotation of crops, are useful, but the pickle worm has never been successfully combated. The writer suggests the combined use of arsenate of lead and Paris green, spraying with the former, at the rate of one pound to from 15 to 25 gallons of water, beginning at about the time that the buds commence to form, and making a second application a week or two later, according to how well the arsenate remains on the foliage. A third spraying may be made if necessary, following with a final :pray of Paris green (1 pound to 130 gallons water) within about a week of the time of the ripening of the fruit. As the arsenate is very adhesive, its use is not advised for the final spraying. The Paris green which is substituted at this stage is perfectly harmless, as it readily washes off if, indeed, any will remain by the time the fruit is placed on sale. This treatment is designed to kill the "worms" before they enter the fruit, since they cannot be reached after they have obtained entrance. The "worms" are poisoned while feeding on the buds, leaves and other parts, as well as on the rind of the fruit. The Melon Caterpillar (Diaphania hyalinata Linn.). — This species and the preceding resemble each other in many partic- ulars and are especially alike in their larval stages, but there 174 INSECTS INJURIOUS TO VEGETABLES is this difference, important to the grower, that the first genera- tion of the melon caterpillar usually attacks the foliage, partic- ularly of muskmelon, to which it, as well as the preceding, is most destructive. By reason of this habit we can control it, in Fig. 1 14.— Melon caterpillar. Moths, larva and pupa in case. Natural size (From Comstock) a measure at least, with stomach poisons, which is impossible with the pickle worm, since the latter lives internally through- out its later larval stages. The parent insect has the wings pearly white, with a strong iridescence, and bordered with brown (fig. 114). The cater- pillar when full grown is a trifle smaller than the pickle worm, measuring about eight-tenths of an inch. It is pale, greenish yellow, with black mouth-parts. It is southern in distribution, INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 1 75 occurring abundantly in the Gulf States. The "worms" of these two species are frequently confounded because of their similar appearance. Both feed in the same fields and their life habits exhibit little variation. Remedies mentioned for the pickle worm are applicable, as the melon caterpillar can be killed readily by an arsenical spray. Miscellaneous Pests. — The onion thrips, considered on pages 89 and 90, the wheat thrips (page 90) and the red spider (page 91) are all important enemies of cucumbers grown under glass, as is also the greenhouse white fly (Aleyrodes vaporariorum Westw., fig. 114^). In- deed in the case of the last mentioned pest it would be impossible to grow this crop in forcing houses without the em- ployment of remedial measures. This pest can be held in control by vaporization or fumigation with tobacco or nicotine extracts, or by spraying with kerosene emulsion or the so-called whale- oil (fish-oil) soap. Care is necessary in using the extracts that the smudge does Fig-, wax— Greenhouse not become too dense and injure the ^tlL^t^ plants. Before applying this remedy on nified. (After Morrill.) a large scale a preliminary trial should be made following the directions on the packages, and reducing the amount if any ill results follow. Hydrocyanic acid gas properly used is an ex- cellent remedy. 1 1 See Circ. 57, Bu. Entom.. U. S. Dept. Agr., and Fumigation Methods, by Prof. W. G. Johnson, published by Orange Judd Company, New York. CHAPTER XI INSECTS INJURIOUS TO CELERY, PARSNIPS AND RELATED PLANTS A considerable number of insects attack celery, but few are restricted to it as a food, and fewer yet do noticeable damage. A large proportion of the insects which live on it also attack carrot, parsnip, and parsley, preferring one or the other of these three plants. For convenience, however, we may con- sider the insect enemies of celery separately. INSECTS INJURIOUS TO CELERY What is true in this country is equally true in Europe, and there is little danger of the introduction of important pests from abroad. With the increased cultivation of this crop insects which now attack it may increase in injuriousness, but there is no immediate prospect of serious losses accruing from insect at- tack. It is seldom that beds of celery are entirely free from the celery caterpillar; the same may be said of the zebra cater- pillar. The tarnished plant-bug is one of the worst enemies with which the celery grower has to contend, but its having many host plants usually distributes attack except in unusual seasons. Celery generally escapes the ravages of cutworms owing to its late planting and still later replanting, and neither white grubs nor wireworms deter its growth as far as observa- tions go, presumably because of its powerful root and root stalk. The leaves are attacked by leaf-rollers and leaf-tyers and one of these, the celery leaf-tyer, is of considerable im- portance. The Carrot Rust Fly (Psila rosce Fab.). — This pest has been injurious to carrots in Canada since 1885 and made its ap- 176 . INSECTS INJURIOUS TO CELERY, PARSNIPS, ETC. 177 pearance in 1901 in New York in celery fields. In attack on celery the leaves of young plants early in spring turn reddish, and the roots are blotched with rusty patches, particularly toward their tips. Roots of carrot when stored for winter, al- though not manifesting any degree of injury on the outer surface, are at times perforated in all directions by dirty brown- Fig. 115.— Carrot rust fly. $ . Male fly; $ , female fly; a, antenna of male; b, full- grown larva, lateral view; c, spiracles of same; d- anal extremity; e, puparium; /. young larva; g, anal segment from side. Flies, young and mature larva, and puparium, eight times natural size; other portions more enlarged. (Author's illustration, U. S- Dept. Agr.) ish burrows, from which these whitish yellow maggots may be found projecting. When celery is infested the larvae seem to begin eating into the thick part of the root when the plant is about half grown, stunting it so as to make it worthless for market. This species is quite minute, the parent fly measuring only about one-sixth of an inch in length, with a wing expanse of a little more than three-tenths of an inch. The body is dark green and is rather sparsely clothed with yellow hairs. The head and legs are pale yellow, and the eyes black. The two sexes are shown at $ and $, figure 115. According to Curtis, when the imago issues from the puparium an oval lid on this portion lifts up, permitting the fly to crawl out. The posteiior extremity ends in two minute dark tubercles. The carrot rust fly is a pest in Europe, whence it has been introduced in this country. It is a northern species and is I78 INSECTS INJURIOUS TO VEGETABLES permanently established in New Brunswick, Ontario and Que- bec, Canada, besides occuring in New York and New Hamp- shire. The life history of the carrot fly has not been entirely worked out. In the United States it will probably be found to pass the winter usually as a puparium, but as larvae work also on carrots in store, the flies develop in winter, hence we have great irregularity in development, making generalization im- possible until observations are made in the field. The insect develops rather early in the season and both flies and maggots are found throughout the warmer months, but the latter desert the roots for pupation in the earth, the last generation probably descending much deeper than the earlier ones. Curtis states that the summer generations develop in three or four weeks. There are at least two, and probably more, generations annually. Miss Ormerod has observed that the female fly goes down into the ground where she can find a crack or other opening about the roots of the plant affected. Here she lays her eggs, and the maggots, when hatched, work their way into the root; when this is quite small they often destroy the lower portion. METHODS OF CONTROL The carrot rust fly is difficult to reach with insecticides. Our principal dependence is based upon methods of tillage which will avert attack. Kerosene emulsion in the proportion of one part to ten of water sprayed upon the carrots along the rows, or sand, or ashes, with which kerosene is mixed at the rate of half a pint to three gallons, sprinkled along the rows, have given good results. These substances deter the fly from laying her eggs. Late sowing and rotation of crops are excellent remedies, as is also the planting of new beds as far as possible from land infested the previous season. INSECTS INJURIOUS TO CELERY, PARSNIPS, ETC. 179 Destruction of stored carrots. — Where carrots are stored for winter use in earth they should be treated to destroy the larvae or puparia. This may be accomplished by burying the earth deeply; by spreading it in thin layers where it will be exposed to the elements; by throwing it into pools where it will be frozen; or by exposing it to heat or steam in any convenient manner. Treatment of celery beds. — As this insect also infests celery, that crop should not follow carrots (nor carrots celery) in rotation. Clean farming should be practiced, which includes the destruction of remnants after the crop has been harvested. After harvest, it would be a good plan to give celery fields a raking or cultivating of sufficient depth to expose the larvae or puparia to frost; early the following spring, before the flies issue, if the earth be plowed deeply, it will have the effect of destroying such insects as have not been killed by frost and survive cultivating and raking. The Celery Caterpillar (Papilio polygenes Fab.). — Because of its large size and brilliant colors, both as larva and adult, this is one of the best known of the enemies of celery and allied plants. The caterpillar is green, or yellowish, and ringed with black and spotted with yellow. It attains a length of two inches. The parent insect is known as the black swallow-tail. It is velvet black, relieved by yellow bands in the male. The hind- wings are ornamented on the interior margin by eye-like mark- ings like those of the peacock and the wings terminate in the tails from which it derives its common name. The female is somewhat faded black and of more sombre appearance than her mate. The wing expanse is about three inches. The chrysalis is dull gray, mottled with dull brown. It measures a little less than one and one-fourth inches. The celery cater- pillar is one of the most interesting insects that attack garden plants. It appears to be limited to no special life zone, occur- ring throughout Canada and every State and Territory in the l8o INSECTS INJURIOUS TO VEGETABLES Union, southward through Central America and the West Indies to Venezuela. The young larvae are utterly dissimilar to the mature ones, and five distinct stages have been noted. This insect affects practically all umbelliferous crops, celery, carrot, parsley, caraway, fennel, parsnip, dill, and related wild plants. It does not appear to attack, except in extreme cases, any plant outside of this botanical family. Remedies. — The conspicuous coloration of the celery cater- pillars renders them an "easy mark" as they are readily found and can be crushed under foot, and no other remedies are necessary if the work of destruction is begun before the plants are injured. The killing off of the first generation will serve in considerable measure to destroy the insects for the second brood, if this work be done over a considerable area. The butterfly, however, is strong of flight, and cooperation must be had to keep the insect in check when it becomes destructive. The Celery Leaf-tyer (Phlyctamia ferrugalis Hbn.) 1 .— This little insect, known also as the greenhouse leaf-tyer, first came to notice as a pest in 1888. On celery it feeds by preference on terminal leaves, and sometimes burrows into the stems. On one occasion in the District of Columbia it was so destructive that one grower had determined to abandon celery culture on this account. Next year, however, the insect was less trouble- some; and this was fortunate, for if it were not periodical it might be a very bad pest indeed. In the field this leaf-tyer attacks besides celery cabbage, beets, tobacco, lettuce, cauli- flower, parsley, cucumber, sweet pea and strawberry. It causes great injury to many greenhouse plants — violet, rose, chrysan- themum, carnation, ivy, heliotrope, and others. The moth is a pale reddish-brown, expanding about three-fourths of an inch. The fore-wings are pale clay brown, suffused with reddish or ochreous brown, ornamented with black lines (fig. 116, a, b). The hind-wings are gray, with darker margins. 1 For a detailed account see Bui. 27, Bu. Entom., U. S. Dept. Agr. INSECTS INJURIOUS TO CELERY, PARSNIPS, ETC. l8l This moth resembles that of the garden webworm (page 61). The larva is green or greenish yellow, somewhat translucent, with whitish head, marked with purplish dots (fig. 116, e, d, f). This is an introduced species, and obviously of tropical origin. Owing to its adaptability to indoor habits it is likely to be found anywhere. The leaf-tyers work usually on the under surfaces of leaves, or on such as are shaded by other leaves. When young they eat out small holes on the under surfaces, leaving the upper Fig. 116.— Celery leaf-tyer. a, Moth; b, same in natural position at rest; c, egg mass; d, larva from above; e, same from side; /, head of same; g, pupa case; h, chrysalis. a, b, d, e, g, h, One-half larger than natural size; c, twice natural size; /, more enlarged (original). epidermis untouched; but as they increase in growth the leaves are skeletonized and sometimes entirely devoured. Larvae work chiefly at night and rest by day in the same locations. They prepare for transformation to pupae by spinning up be- tween two leaves, or by rolling up a case at the edge of a leaf. (See fig. 116, g). Owing to the somewhat secluded manner of life of the larva, attack is not noticeable until considerable injury is done; but its presence can be readily ascertained by striking the plants lightly, when the moths start up, fly a short distance, then alight, and disappear under a leaf. In mid- summer the entire life cycle, according to the writer's observa- 1 82 INSECTS INJURIOUS TO VEGETABLES tions, may be passed in five weeks, but the outdoor spring and fall generations require a longer period. There are at least two, and frequently three, generations produced in the open; and in a warm equable indoor temperature there is a possibility of four and perhaps five. Remedies. — In greenhouses this leaf-tyer is controlled by trimming away and destroying infested leaves as often as they are detected. The moths are killed in great numbers by placing lights over vessels of water on which a thin scum of kerosene floats. These remedies are less valuable in the field, but Paris green and other arsenical sprays, if applied at the outset of Fig. 1 1 7.— Celery looper. Male moth at left, larva at right. Somewhat enlarged (Author's illustration, U. S. Dept. Agr.) attack, will destroy the larvae, though less effective after they have become concealed in their tied-up leaves and in the growth of leaves about them. Spraying should be thorough, and an underspray is desirable. The Celery Looper (Plusia simplex Guen.}. — This species is the commonest of its kind in Illinois, and is rather generally distributed in the United States east of the Rocky Mountains, from Canada to New Mexico. It is described by Messrs. Forbes & Hart as a very destructive celery insect, and occurs also on sugar beet and lettuce. The moth (fig. 117) has a greater wing expanse than the cabbage looper, measuring nearly two inches, has different coloration, and differently shaped upper-wings. The border of the fore-wings is not scalloped, the color is somewhat purplish INSECTS INJURIOUS TO CELERY, PARSNIPS, ETC. 183 brown, the darker shades velvety brown. The larva is similar to the cabbage looper and similar remedies are applicable. The Little Negro Bug {Corimelcena pulicaria Germ.). — This minute black bug sometimes does considerable damage to celery, as happened in 1893, when attack was quite general throughout the celery-growing portions of Michigan. The insects collect in clusters around the nodes where the three top leaflets meet. Here they suck the sap until the leaflets wilt and droop, after which they go to the joint below and repeat the operation till the leaf is drained of sap. The mature negro bug measures only about an eighth of an inch, and is glossy black, the scutellum occupying over half of the upper surface and being surrounded by a white margin. This insect is common and well distributed. It prefers old celery when about ready for blanching and plants are retarded in growth from two to three weeks, recovering with large numbers of small curling, gnarly stalks of little or no market value. In such cases the crop is practically an entire loss. This species is a general feeder attacking numerous garden plants, among which are strawberry and blackberry, and it is due in part to this insect that these berries sometimes have such a disgustingly sour taste, and "buggy" odor, particularly when picked in the field. Remedies. — Carbolic or kerosene emulsion are useful both as destroyers and repellents. In experiments conducted by Mr. G. C. Davis, the bugs were readily killed with hot water at a temperature of 155 F., acid the celery plants were found to endure a stream heated to 175 . This remedy is most effective when the insects first appear and when applied on the plants where they are most numerous. It necessitates the use of a thermometer that the temperature may not go above 175 . Celery should not be planted in the vicinity of weedy fields, especially those containing umbellifers, as these harbor the insects sometimes in enormous numbers. 184 INSECTS INJURIOUS TO VEGETABLES INSECTS INJURIOUS TO CARROTS, PARSNIPS AND PARSLEY In this category we include parsley although it does not seem to have any insect enemies of its own. These plants belong to the same family (Umbelliferae) as celery, and as stated in a preceding page most of the insects enumerated as affecting that plant are liable to attack these also, but both parsnip and carrot have particular species that infest them, Fig. 118.— Parsnip leaf-miner, o, Fly; b, larva; c. cephalic extremity of larva; d, anal extremity; e, /, spiracles- All enlarged. (After Coquillett, U. S. Dept. Agr.) because they are planted for their roots and not for their delicate stalks, as in the case of celery, which renders the por- tions above ground more rank and those below ground more tender, while each plant (parsnip and carrot) has a flavor peculiar to itself. Thus it happens that the leaves of parsnip are more affected by the parsnip leaf-miner, while the roots of carrot are preferred by the carrot beetle and carrot rust fly. The Parsnip Leaf -miner (Acidia fratria Loew.). — The economic history of this species begins with 1891, when parsnip leaves in Missouri were quite extensively mined by its larva. INSECTS INJURIOUS TO CELERY, PARSNIPS, ETC. 185 The adults issued June 23. The insect which produces this maggot is shown at figure 118, a. It belongs to the same family as the apple maggot or railroad worm, and it will be seen that it is a two-winged fly, with rather prettily marked wings. It is pale dull- yellow, and the wings are marked with the same color. The legs are still paler, and the eyes are brown. The head and thorax above bear long, stiff bristles. This fly measures about three-sixteenths of an inch in length, and has a wing expanse at least double that. It ranges from the Atlantic seaboard westward to Missouri and probably farther. Little is known of its life history, but it will probably be found to affect other umbelliferous crop plants and weeds. Remedies advised against the radish leaf-miner (page 154) are applicable. The Carrot Beetle {Li gyrus gibbosus DeG.). — This beetle is the worst insect enemy to carrot and parsnip in this country. It is a native species and of common oc- currence along the Atlantic Coast from Long Island to the Gulf and Pacific States and at many points inland. It injures be- sides the plants specified various root crops and some other plants. The beetle might be mistaken for a May beetle, but the wingcovers are strongly sculptured and coarsely punctate, char- acters' which are wanting in true May p . g ® 9 ._ Carr0t f eetle . beetles (Lachnosterna). The beetle (fig. About twice natural size. 119) is of robust form, measuring between g^^^*"' ""* one-half and five-eighths of an inch in length, with short legs. The color varies from reddish brown to nearly black on the dorsal surface. Larval injury has been noted, but there is little doubt that the grubs feed also on humus, manure and decomposing roots and tap roots of herbaceous plants. Larvae have been observed to feed on earth where there 1 86 INSECTS INJURIOUS TO VEGETABLES was no opportunity for plant attack. Most cases of injury are due to the operations of the beetles, and damage is more pro- nounced on young plants, older growth appearing in some cases exempt from attack, owing to its more woody texture. Injury may be accomplished both by hibernated individuals in the spring from April to June, according to locality, and by recently transformed specimens in late summer and autumn. The species is with little doubt single-brooded. Pupation takes place in an oval cavity in the earth, and hibernation, without much doubt, occurs in the adult condition. The favorite food of the beetle is evidently carrot, and after this corn, parsnip and celery are chosen. Sweet and Irish potato are subject to much damage, as are also sunflower, dahlia, sugar- beet and sometimes cotton. The beetles usually feed beneath the surface; corn is cut just above the roots, and root crops are punctured with holes. Sometimes a crop appears in good condi- tion, judging from the tops alone, but when the plants are pulled injury becomes manifest. Entire plantings have been destroyed by the beetles, and the roots of tubers rendered un- marketable on account of their ravages. They gnaw into the roots of celery, dwarfing and killing the plants, and eat the bark from the root. They sometimes imbed themselves in tap roots and may penetrate the earth to a depth of seven inches. As many as fifty beetles have been found about the roots of a single plant. Methods of Control. — When this insect is present in large numbers there is little, owing to its working underground, that can be accomplished in the line of control. The beetles are strongly attracted to electric lights, but it is not certain that they could be lured from the field after beginning to feed. It is reported that lime scattered through infested fields has ap- parently driven the beetles away. After the crop has been har- vested, if the insects continue in numbers in the ground, it would INSECTS INJURIOUS TO CELERY, PARSNIPS, ETC. 187 be profitable to turn in hogs or chickens. Crop rotation and other white-grub remedies should be practiced. The Parsnip Webworm (Depressaria heracliana DeG.). — The parsnip webworm is injurious to the seed of parsnip, but for some reason, at least in the experience of the writer, prefers the wild carrot as a breeding plant. The moth is grayish buff, or pale ochraceous, with the fore-wings marked with fuscous (fig. 120, e). The larva is pale yellow, greenish or bluish gray, marked with black, piliferous spots, and with bluish black head Fig. 120.— Parsnip webworm. a, Mcfth; b. c, caterpillars: d, chrysalis; e anal segment of same; /. umbel of parsnip, webbed together by caterpillar, a- e. Enlarged; /, some- what reduced. (After Riley ) and thoracic plate, as figured (a, b). The species is of general occurrence through the northern portions of Europe and our Atlantic States and Canada westward to Michigan. Wild carrot and parsnip, which are altogether too abundant in fields throughout that section, yield it a sufficiency of food and in some years it is difficult to find these weeds that are not affected by the webworm. The larvae weave the flower heads (/) together until these are contracted into masses, with abundant excrement as a covering. Within the domicile thus formed the larvae dwell. After they have consumed the flowers and unripe 1 88 INSECTS INJURIOUS TO VEGETABLES seeds and are nearly mature, they enter the stems, feed on the soft lining, and transform to pupae. They sometimes destroy newly-sown parsnip, eating the tender leaves, but in attack on older plants they eat the umbels or flower heads and the inte- rior of the stems. Remedies. — A thorough spraying with arsenicals will destroy this webworm. To prevent injury by it avoid planting parsnips in or near waste places which have become overrun with wild carrot. Miscellaneous Insects. — Among other insects injurious to celery the tarnished plant-bug is an important species. It is figured and described on pages 87 and 88. The cotton leaf-bug (Calocoris rapidus Say), a species of somewhat similar habits and appearance (fig. 120^), also attacks celery and is amenable to the same remedial treatment. CHAPTER XII INSECTS INJURIOUS TO SWEET CORN A greater number of species of insects have been recognized as attacking Indian corn than any other plant grown as a vegetable. Although, properly speaking, corn is a field crop, it is also grown for the sake of the unripe ears which are classi- fied as vegetables. What insects will attack field corn will also attack the garden variety, but for present purposes it will not be necessary to treat of any except the more important habitually garden-inhabiting species, and only a few of these need be considered at all in detail. Many of them are general feeders and have been considered in preceding paragraphs. The corn-feeding species of insects recognized in 1896 were 214 in number, and of these 18 attacked the seed, 27 the root and lower portions of the stalk, 76 the stalk above ground, 118 the leaf, 19 the tassel and silk, and 42 the ear. The remainder attacked the stored product. It is safe to say that at the present writing (1907) at least 350 species are on record as concerned in attack on corn. The Corn Root-aphis (Aphis maidiradicis Forbes). — Con- cerning this species, Dr. S. A. Forbes wrote in 1896: "No in- sect affecting corn is more deserving of the attention of farmers and entomologists at the present time than the corn root-aphis. It ranks as a corn pest with the chinch bug and the army worm, less injurious at any one time than these are locally and occa- sionally, but overtaking them, on the other hand, by its general distribution and the constancy of its attack." This root-aphis does its principal injury while corn is small. The dwarfing of a plant in patches with a yellowing or reddening of the leaves, and 189 190 INSECTS INJURIOUS TO VEGETABLES a lack of thrift and vigor, are the outward manifestations of injury. Another indication is the presence of numerous small brown ants which attend this species and without which it probably could not exist. The corn root-aphis is bluish green, slightly whitened by a waxy bloom. The body is oval, and the nectaries are erect or Fig. 121.— Winged viviparous female of corn root-aphis; wingless egg-laying female. Enlarged. (After Forbes) project slightly backwards. Two of the different forms are shown in figure 121. It is found from Massachusetts to Minne- sota and Nebraska and as far south at least as Virginia. The winged forms migrate to various weeds, among which are smartweed, pigeon grass, mustard, pigweed and plantain. Economic Treatment. — Our present knowledge of this insect suggests several methods of attacking it. Crop rotation and care not to plant in or near fields of weeds which serve as alternate hosts; the free use of manures and other fertilizers to stimulate the growth of the plants; the disturbing and destruc- tion of the nests of the protecting ants; the destruction of all of the weeds which serve the aphides as food early in the season by plowing, and, in connection with this, late planting of corn. 1 Such measures of procedure may not entirely pro- tect the crops in all localities in all seasons. 1 These and other remedies are considered in detail by F. M. Webster in Circ. 86, Bu. Entom., U. S. Dept. Agr. INSECTS INJURIOUS TO SWEET CORN 191 The Southern Corn Root-worm (Diabrotica 12-punctata 01.). ■ — The larvae of two species of leaf-beetles are among the promi- nent enemies to the culture of corn by destroying the roots. One of these, the Southern corn root-worm is common nearly throughout the United States, but as its name implies is most destructive in the South. In the case of its attack not alone roots, but underground stalks are injured. The other, known as the Western corn root-worm, is somewhat confined to the middle West, where it would be a very serious pest were it not that farmers generally in that region have adopted a sys- tem of rotation which greatly reduces injury. The principal form of its attack is in the interior of the fibrous roots, in which minute, more or less longitudinal, burrows are formed. The larva of the Southern species is also called in the South the "bud-worm" and "drill-worm." The beetle is commonly known northward as the twelve-spotted cucumber beetle be- cause of its frequenting the flowers of cucumber, as well as squash, and other cucurbits in the interior of which one can usually see one or more dusted with pollen, and the places where they have gnawed the petals, for they are mbst omnivorous in- sects and able to subsist on nearly any form of vegetation on which they happen to alight. They are, in fact, to be found in practically all fields of corn and in gardens everywhere. The beetle is yellowish green, and the wing-covers are marked with twelve black spots (fig. 122, a). The length is one-quarter of an inch or a little longer. The larvae (c) are slender, thread-like, delicate and soft bodied, and white or yel- lowish in color. The twelve-spotted cucumber beetle inhabits that portion of America lying between the Atlantic seacoast to the base of the Rocky Mountains, and from Canada to Mexico. It is a very common species and most destructive in the South, where in- jury is accomplished by its root-worm form as far northward as Maryland and Virginia. 192 INSECTS INJURIOUS TO VEGETABLES The adult is practically omnivorous, its known food ma- terials are legion, and include besides the pollen and flowers and partly matured kernels of corn, wheat and oats, the foliage of alfalfa, crimson clover, cotton, rye and tobacco. Of vege- tables it attacks all forms. It frequently injures the fruit of melon and other cucurbits. Larvae or pupae have been ob- served at the roots of corn, wheat, rye, millet, beans, rudbeckia Fig. 122.— Southern corn root-worm, a, Beetle; b. egg; c, larva; d, last segment of same; e- section of cornstalk showing holes made by larvae; /, pupa, into Texas. Remedies. — Gathering and destroying the fallen pepper pods in which the larva feeds and the beetle develops or burying the infested pods by bedding high and lowering the soil are suggested as methods of control. Where pepper is grown in irrigated land this practice serves to check the insects, as the iSee list, Insect Life, Vol. II., page 259. INSECTS INJURIOUS TO MISCELLANEOUS CROPS 25 1 decay of the pods is hastened and the larvae are thus deprived of a food supply. 1 Some of the potato and tomato pests considered in earlier pages occasionally infest peppers, but do not as a rule do notice- able injury. Among these are the tomato worms, bollworm, white fly, and Colorado potato beetle. 1 This species is treated under the name of Anthonomus aneotvictus Champ, in Bui. 54, Bur. Ent., U. S. Dept. Agr., pp. 43-48, and Bui. 63, pp. 55-58, by C. M. Walker and F. C. Pratt respectively. CHAPTER XVII BIBLIOGRAPHY ■ A short list of some of the more important and readily- available publications on economic entomology in which the insects injurious to vegetable crops are treated follows. In compiling such a list some precedence is given to the publica- tions of the Federal Department of Agriculture because as a rule they have a wider scope than State Agricultural Experiment Station publications, are printed in larger editions and are ac- cessible to all, being for the most part free on application. Many of these contain bibliographical references. The list begins with works on general and economic entomology. WORKS ON GENERAL AND ECONOMIC ENTOMOLOGY 1 841. Harris, T. W. — Insects Injurious to Vegetation. Flint ed., 185 1. Orange Judd Co., New York. First ed., Cambridge, 1841. 1855. Fitch, Asa — Reports of the State Entomologist of New York. I.-XIV., Albany, 1855-1870. (See Lintner's First Annual Report, State Ent. New York, pp. 294-297.) 1865. The Practical Entomologist. Vols. I. and II. Published by the Entomological Society of Philadelphia, 1865-1867. 1868. The American Entomologist, edited by B. D. Walsh and C. V. Riley. Vols. I.-IIL, 1868-1880. 1869. Riley, C. V. — Reports of the State Entomologist of Missouri. I.-IX. Jefferson City, 1869-1877. 1879. Reports of the Entomologists of the U. S. Department of Agriculture. J. H. Comstock (1879-1880) ; C. V. Riley (1878-1879, 1880-1894). L. O. Howard (1894 to date). 1882. Lintner, J. A. — Reports of the State Entomologist of New York, I.-XIV. Albany, i882-'97. 1882. Treat, Mary — Injurious Insects of the Farm and Garden. Orange Judd Co., 1882. (A small work compiled from Riley's reports.) 1883. Forbes, S. A. — Reports of the State Entomologist of Illinois, I.-XXIII. 1883-1905- 1891. Weed, C. M. — Insects and Insecticides. 281 pp., 143 figs. Han- over, N. H., 1891. 1895. Comstock, J. H. and Anna B — A Manual for the Study of Insects. 701 pp., 797 figs. Ithaca, N. Y. 252 BIBLIOGRAPHY 253 1896. Smith, J. B. — Economic Entomology. 481 pp., 483 figs. Phil- adelphia, 1896. 1902. Johnson, W. G.— Fumigation Methods. Orange Judd Co., New York. 313 pp., 83 figs. 1902. Sanderson, E. D. — Insects Injurious to Staple Crops. New York. 295 pp., 162 figs. Bulletins of the Division and Bureau of Entomology of the U. S. Department of Agriculture, I-XXXIIL, o. s., 1883-1895, 1-71, 11. s., 1896-1907. (Buls. 19, 23, 29, S3 and 43 treat of insects injurious to vegetables.) Insect Life, vols. I.-VIL, 1888-1897. Circulars, Division and Bureau Ent. U. S. Dept. Agr., 1891-1907. (Ore's. 10, 16, 31, 38, 39, 43, 57, 59, 60, 62, 63, 65, 80 and 87 treat of insects which affect vegetable crops.) The publications of the various state, agricultural experiment stations may be obtained by residents of the States where these documents are issued. GENERAL CROP PESTS Cutworms. Smith — Bui. 109, New Jersey Agr. Exp. Sta., pp. 3-13, figs. 1-3, 1895 ; Slingerland — Bui. 104, Cornell Univ. Agr. Exp. Sta., pp. 553-6oo, figs., 1895. Spotted Cutworm (Noctua c-nigrum Linn). Chittenden — Bui. 27, n. s., Div. Ent. U. S. Dept. Agr., pp. 54-58, 1901. Variegated Cutworm (Peridroma saucia Hon. [Agrotis saucia]). Chittenden — Bui. 29, n. s., Div. Ent. U. S. Dept. Agr., pp. 46-64, 1901 (includes bibliography). Black Cutworm (Agrotis ypsilon Rott). Riley — Rept. U. S. Dept. Agr. f. 1884, pp. 294, 295, 1885. Army Worm (Heliophila unipuncta Haw. [Leucania unipuncta]). Howard — Circ. 4, Div. Ent. U. S. Dept. Agr., 1894; Slin- gerland — Bui. 133, Cornell Univ. Agr. Exp. Sta., pp. 233- 258, 1897. Fall Army Worm or Grass Worm (Laphygma frugiperda S. & A.). Chittenden — Bui. 29, n. s., Div. Ent. U. S. Dept. Agr., PP- 13-45, 1901 (Bibliography). Wireworms. Comstock and Slingerland — Bui. S3> Cornell Univ. Agr. Exp. Sta., pp. 193-272, figs., 1891 ; Slingerland — Bui. 107, Cornell Univ. Agr. Exp. Sta., pp. 37-56, 1896; Forbes — 18th Rept. St. Ent. Ills., pp. 27-51, 1894. White Grubs. Forbes, S. A.— 18th Rept. St. Ent. Ills., pp. 109-145, 1894; Bui. 44, Univ. Ills. Agr. Exp. Sta., pp. 257-281, 1896; Chittenden — Bui. 19, n. s., Div. Ent. U. S. Dept. Agr., pp. 67-80, 1899. Grasshoppers or Locusts. Riley — Bui. 25, o. s., Div. Ent. U. S. Dept. Agr., pp. 1-62, figs, and pis., 1891. (Compiled from 1st and 2nd Repts. U. S. Ent. Comm., etc.) Pale-striped Flea-beetle (Systena blanda Mels. [S. tmiiata Say]). Chittenden — Bui. 23, Div. Ent. U. S. Dept. Agr., pp. 23-30, 1900. 254 INSECTS INJURIOUS TO VEGETABLES Red Spider (Tetranychus bimaculatus Haw. [T. telarius Authors]). Chittenden — Bui. 27, n. s., Div. Ent, U. S. Dept. Agr., pp. 35-42, 1901. ASPARAGUS General. Chittenden — Bui. 10, n. s., Div. Ent. U. S. Dept. Agr., pp. 54-62, 1898. Common Asparagus Beetle {Crioceris asparagi L.). Chittenden — Ybk. U. S. Dept. Agr. f. 1896 (1897), PP- 341-349 5 Bui. 66, Bu. Ent., pp. 6-9, 1907 Twelve-spotted Asparagus Beetle {Crioceris 12-punctata 01.). Chittenden— Ybk. U. S. Dept. Agr. f. 1896 (1897), pp. 349-352; Bui. 66, Bu. Ent., pp. 9, 10, 1907. Asparagus Miner {Agromyza simplex Loew.). L. c, pp. 1-5, figs. 1 and 2, 1907. BEANS AND PEAS General. Chittenden— Ybk. U. S. Dept. Agr. 1898 (1899), pp. 233- 280, figs. Bean Leaf-beetle {Cerotoma trifurcata Forst. [C. caminea Fab.]) Chittenden — Bui. 23, n. s., Div. Ent. U. S. Dept. Agr., pp 30, 31, 1900. Pea Aphis {Nectarophora destructor Johns. [Nectarophora pisi]) Chittenden — Bui. 23, n. s., Div. Ent, U. S. Dept. Agr., pp 33-37, hg- 9, 1900. Bean Leaf -roller {Eudamus proteus Linn.). Chittenden — Bui 33, n. s., Div. Ent. U. S. Dept. Agr., pp. 92-96, fig. 20, 1902, Lima-bean Stem-borer {Monoptilota nubilella Hulst). Chitten- den — Bui. 23, n. s., Div. Ent. U. S. Dept. Agr., pp. 9-17, 1900. Smaller Corn Stalk-borer (Elasmo palpus lignosellus Zell.). Chit- tenden— Bui. 23, n. s., Div. Ent. U. S. Dept. Agr., pp. 17- 22, 1900. BEETS AND SPINACH General. Forbes and Hart — Bui 60, Ills. Agr. Exp. Sta., pp. 397- 532, figs. 97, pis. I.-IX., 1900. (A monographic account with bibliography) ; Chittenden — Bui. 43, Div. Ent. U. S. Dept. Agr., pp. 1-71, figs., 1903. (Short accounts of princi- pal insect enemies.) Leaf -miner {Pegomya vicina Lint.). Sirrine — 14th Annual Rept. Board of Control, N. Y. Agr. Exp. Sta., pp. 625-633, PI. IV.. 1896. BIBLIOGRAPHY 255 Larger Beet Leaf -beetle (Monoxia puncticollis Say. [Galeruca maritima]). Chittenden — Bui. 18, n. s., Div. Ent. U. S. Dept. Agr., p. 95, 1898. Beet Aphis (Pemphigus beta? Doane). Doane— Bui. 42, Wash. State Agr. Exp. Sta., 14 pp., 4 figs., 1900. Beet Army Worm (Laphygma exigua Hbn.). Chittenden— Bui. 33, n. s., Div. Ent. U. S. Dept. Agr., pp. 37-46, fig., 1902. Beet Webworm (Loxostege sticticalis Guen.). Gillette — 13th Ann. Rept. Colo. Agr. Exp. Sta., pp. 128-130, 1900 (1901) ; Bui. 98, Agr. Exp. Sta. Colo., pp. 3-12, pis. I. and II., 1905. CABBAGE AND OTHER COLE CROPS Cabbage Maggot (Pegomya [Phorbia] brassicce Bouche). Chit- tenden — Circ. 63, Bu. Ent., U. S. Dept. Agr., pp. 3-6, figs., 1906; Slingerland— Bui. 78, Cornell Univ. Agr. Exp. Sta., pp. 481-577, 1894; Smith — Bui. 200, N. J. Agr. Exp. Sta., pp. 1-27, 13 figs., 1907. Imported Cabbage Worm (Pontia rapes Linn.). Chittenden — Circ. 60, Bu. Ent., U. S. Dept. Agr., 8 pp., 6 figs., April, 1905. Cross-striped Cabbage Worm (Evergestis [Pionea] rimosalis Guen.). Chittenden — Bui. 33, n. s., Div. Ent., U. S. Dept. Agr., pp. 54-59, 1902. Cabbage Looper (Autographa brassicce Riley [Plusia brassier]). Chittenden — Bui. 33, n. s., Div. Ent., U. S. Dept. Agr., pp. 60-69, 1902. Imported Cabbage Webworm (Hellula undalis Fab.). Chitten- den — Bui. 19, n. s., Div. Ent., U. S. Dept. Agr., pp. 51-57, 1899. CUCUMBER, MELON AND RELATED PLANTS General. Quaintance — Bui. 45, Ga. Agr. Exp. Sta., pp. 25-50, figs., 1899; Smith — Bui. 94, N. J. Agr. Coll. Exp. Sta., pp. 3-40, 1893. Striped Cucumber Beetle (Diabrotica vittata Fab.). Chitten- den — Bui. 19, n. s., Div. Ent. U. S. Dept. Agr., pp. 48-51, 1899; Circ. 31, Div. Ent. U. S. Dept. Agr., 1898. Twelve-spotted Cucumber Beetle (Diabrotica duodecimpunctata Oliv.). See Corn root-worms. Squash Ladybird (Epilachna borealis Fab.). Chittenden — Bui. 19, n. s., Div. Ent. U. S. Dept. Agr., pp. 11-20, 1899. (In- cludes bibliography). Melon Aphis (Aphis gossypii Glov. [Aphis cucutneris Forbes]). Chittenden — Circ. 80, Bu. Ent. U. S. Dept. Agr., 16 pp., 6 figs., 1906. Squash Bug (Anasa tristis DeG.). Chittenden — Circ. 39, Div. Ent. U. S. Dept. Agr., 1899; Bui. 19, n. s., Div. Ent., pp. 20- 28, 189 256 INSECTS INJURIOUS TO VEGETABLES Squash-vine Borer (Melittia satyriniformis Hbn. [Algeria cucur- bitce and Melittia ceto]). Chittenden — Bui. 19, n. s., Div. Ent. U. S. Dept. Agr., pp. 34~40> 1899; Circ. 38, Div. Ent. U. S. Dept. Agr., 1899. Pickle Worm (Diaphania nitidalis Cram. [Eudioptis and Margaro- nia nitidalis]). Chittenden — Bui. 19, n. s., Div. Ent. U. S. Dept Agr., pp. 40-42, 1899; Lintner — nth Rept. N. Y. St. Ent, pp. 126-133, 1896; Quaintance — Bui. 54, Ga. Agr. Exp. Sta., pp. 73-91, figs., 1901 (including bibliography). Melon Caterpillar (Diaphania hyalinata Linn.). Chittenden — Bui. 19, n. s., Div. Ent. U. S. Dept. Agr., pp. 42-44, 1899; Quaintance — Bui. 45, Ga. Agr. Exp. Sta., pp. 42-45, 1899. CELERY, CARROT, PARSLEY AND PARSNIP Celery Looper (Autographa simplex Guen. [Plusia simplex]). Chittenden — Bui. 33, n. s., Div. Ent. U. S. Dept. Agr., PP. 73, 74, 1902. Greenhouse Leaf-tyer (Phlyctcenia ferrugalis Hubn. [P. rubigahs Guen.]). Chittenden — Bui. 27, n. s,, Div. Ent. U. S. Dept. Agr., pp. 7-26, 1901 (including bibliography). Celery Caterpillar (Papilio polyxenes Fab. [P. asterias]). Davis — . Bui. 102, Mich. Agr. Exp. Sta., pp. 21-24, 1893. (For mono- graphic treatment see works of Scudder and Edwards on Butterflies.) Carrot Rust-fly (Psila roses Fab.). Chittenden — Bui. 33, n. s., Div. Ent. U. S. Dept. Agr., pp. 26-32, 1902. Carrot Beetle (Ligyrus gibbosus DeG.). L. c, U. S. Dept. Agr. s PP- 32-37, 1902. Parsnip Webworm (Depressaria heracliana DeG.). Riley — Insect Life, v. 1., pp. 94-98, 1888. Parsnip Leaf-miner (Acidia fratria Loew. [Trypeta fratria]). Coquillett — Insect Life, v. VII., pp. 383, 384. Little Negro Bug (Corimelcena pulicaria Germ.). Davis — Bui. 102, Mich. Agr. Exp. Sta., pp. 13-18, 1893. SWEET CORN General. Forbes— 23rd Rept. St. Ent. Ills., pp. 1-273, figs., pis., 1905 (includes bibliography). Seed-corn Maggot (Pegomya fnsciceps Zett. [Phorbia fusciceps, Anthomyia zece, etc.]). Chittenden — Bui. 33, n. s., Div. Ent. U. S. Dept. Agr., pp. 84-92, 1902 ; Circ. 63, Bu. Ent. U. S. Dept. Agr., pp. 1-3, fig., 1906. Corn Root-worms (Diabrotica longicomis Say. [D. 12-punctata 01.]). Chittenden— Circ. 59, Bu. Ent. U. S. Dept. Agr., 8 pp., 3 figs., 1905. Corn Bill-bugs. General. Forbes— 16th Rept. St. Ent., Ills., pp. 58- 74, 1890; Bui. 79, Ills., Agr. Exp. Sta., 27 pp., 1902. BIBLIOGRAPHY 257 Southern Corn Bill-bug (Sphenophorus maidis Chttn. [Sph. robus- tus Authors]). Forbes — L. c. ; Riley — Rept. Comm. Agr. 1881-2, pp. 138-142, 1883. Clay-colored Bill-bug (Sphenophorus cequalis Linn.). — Treated as Sph. ochreus Lee, by Forbes, 1. c. Northern Corn Bill-bug (Sphenophorus zees Walsh). — Generally called by authors 5". sculptilis Uhl., 1. c. Larger Corn Stalk-borer (Diatrcea saccharalis Zell.). Howard — Circ. 16, Div. Ent. U. S. Dept. Agr., pp. 1-3, 3 figs., 1896. Smaller Corn Stalk-borer (Elasmopalpus lignosellus Zell). Chit- tenden — Bui. 23, n. s., Div. Ent., U. S. Dept. Agr., pp. 17- 22, 1900. Corn-ear Worm; Cotton Bollworm (Heliothis obsoleta Fab. [arm- iger Hbn.]). Quaintance — Farmers' Bui. 191, 1904; Quaintance and Brues — Bui. 50, Bu. Ent. U. S. Dept. Agr., pp. 1-155, figs, and pis., 1905 (includes bibliography). POTATO, EGGPLANT AND RELATED PLANTS General. Riley — Potato Pests, Orange Judd Co., N. Y., pp. 1-108, figs. 48, 1876. Colorado Potato Beetle (Leptinotarsa decemlineata Say. [Doryph- ora 10-lineata]) . Chittenden — Circ. 87, Bu. Ent. U. S. Dept. Agr., 15 pp., 6 figs., 1907. Potato-tuber Worm or Tobacco Split-worm (Phthorimcea oper- culella Zell. [Lita and Gelechia solanella]). Riley and Howard — Insect Life, v. IV., pp. 239-242, 1892; Howard — ■ Farmers' Bui. 120, U. S. Dept. Agr., pp. 19-22, 1900; Clarke — Bui. 135, Cal. Agr. Exp. Sta., 29 pp., 7 figs., 1901. Potato-stalk Weevil (Trichobaris trinotata Say.). Chittenden — Bui. S3, n. s., Div. Ent, U. S. Dept. Agr., pp. 9-19, 1902. Tobacco Flea-beetle (Epitrix parvula Fab.) Chittenden — Bui. 19, n. s., Div. Ent., U. S. Dept. Agr., pp. 85-87, 1899. Potato or Cucumber Flea-beetle (Epitrix cucumeris Harr.). Chittenden — Bui. 19, n. s., Div. Ent, U. S. Dept. Agr., pp. 89, 90, 1899. TOMATO Northern Tobacco Worm or Tomato Worm (Phlegethontius quinquemaculata Haw. [Protoparce celeus]). Howard — Farmers' Bui. 120, U. S. Dept. Agr., pp. 10-14, 1900. Southern Tobacco Worm or Hornblower (Phlegethontius sexta Joh. [Protoparce Carolina']). Howard — L. c, ; Alwood, Bui. 17, n .s., Div. Ent. U. S. Dept. Agr., pp. 72-74, 1898. Common Stalk-borer (Papaipema nitela Guen. [Gortyna nitela]). Smith — Rept. Ent. Dept. N. J. Agr. Coll. Exp. Sta. f. 1905 (1906), pp. 584-587. Greenhouse White Fly (Aleyrodes vaporariorum Westw.). Mor- rill — Circ. 57, Bu. Ent. U. S. Dept. Agr., pp. 1-9, fig., 1905. 258 INSECTS INJURIOUS TO VEGETABLES SWEET POTATO General. Sanderson— Sweet Potato Insects, Bui. 59, Md. Agr. Exp. Sta., 1900. Sweet-potato Root-borer (Cylas formicarius Fab.). Conradi — Bui. 93, Texas Agr. Exp. Sta., pp. 3-16, figs., 1907. Larger Sweet-potato Sawfly (Schizocerus privatus Nort.). Mar- latt— Insect Life v. V., pp. 24-27, fig. 6, 1892. Sweet-potato Flea-beetle (Chcetocnema conilnis Cr.). Smith — 13th Rept. N. J. Agr. Exp. Sta., pp. 472-475, 1892. Mottled Tortoise Beetle (Coptocycla signifera Hbst. [C. guttata]). Sanderson — L. c. Golden Tortoise Beetle (Coptocycla bicolor Fab. [C. aurichalcea]) . — L. c. ONION Imported Onion Maggot (Pegomya ceptorum Meade [Anthomyia and Phorbia ceparum Bouche]). Chittenden — Circ. 63. Bu. Ent. U. S. Dept. Agr., pp. 6, 7, 1906; Smith and Dick- erson — Bui. 200,»N. J. Agr. Exp. Sta., 27 pp., 13 figs., 1907, Onion Thrips (Thrips tabaci Lind.). Pergande — Insect Life, v, VII., pp. 392-395. RHUBARB Rhubarb Curculio (Lixus concavus Say.). Chittenden — Bui. 23, n. s., Div. Ent. U. S. Dept. Agr., pp. 61-69, 1900. INSECTICIDES 1902. Hinds, W. E. — Carbon Bisulphid as an Insecticide. Farmers' Bui. 145, 28 pp. 1902-04. Haywood, J. K. — Reports on Analyses of Insecticides. Buls. 68, 76 and 82, Bu. Chem., U. S. Dept. of Agr. and Farmers' Bui. 146, 16 pp. 1903. Marlatt, C. L. — Important Insecticides. Farmers' Bui. 127, IL S. Dept. Agr., 46 pp., 6 figs. INDEX PAGE Acidia fratria 184, 185 Agriotes mancus 80 Agrotis ypsilon 52, 53 Aleyrodes vaporariorum 175 Alfalfa worm xiv Anasa tristis . •■ 161 — 164 Anthonomus arneotinctus 251 eugenii 250 Apanteles glomeratus ..15, 137, 138 Aphides ......10, 83—85, 127—130 Aphis brassicce 151 — 153 gossypii 165—168, 214 lions 11 maidiradicis 189, 190 rumicis 214 Anachnida, defined 4 Army worm, fall ...56, 59, 208, 209 Arsenate of lead 32 Arsenicals 30—34, 65, 137, 138 harmless 33, 34 Arsenic, white 33 Arsenite of copper 32 lime 33 Asparagus beetle, common . .93 — 96 work, figured x twelve-spotted 96, 97 insects injuring 93 — 97 Autographa brassicce ....7, 140, 142 Bait for insects 54, 55 Barrel spray pumps 45 Bean cutworm 113 ladybird 109, 110 leaf-beetle 110, 111 leaf-roller 112 weevil, common 102 — 104 four-spotted 106 Beans and peas, insects in- juring 100—119 Beet aphides 129, 130 army worm 125 beetle, Western 123 insects injurious to ..120 — 130 leaf-beetle, larger 122, 123 webworm 125, 126 Beetles, defined 6 Bill-bugs, corn 195 — 199 Birds, beneficial 14 Bisulphid of carbon. 42, 102, 133, 167 Blister beetles 66—69, 124 Bollworm, figured xi see also Heliothis 113 Bordeaux mixture ....29, 55, 56, 65 Bran-mash 55, 138 Bruchus chinensis 104 — 106 obtectus 102—104 pisorum 100 — 102 quadrimaculatus . 106 PAGE Brushing methods .. ..27, 116, 117) Bucket pumps 45 "Bud-worm" of corn 191 "Bugging" 27 Buhach, or pyrethrum 40 Burning over fields and waste lands 18 Butterflies, defined 7 Cabbage aphis ....151 — 153 butterfly, Southern 139 flea-beetle, Western ..147, 148 insects injuring 131 — 154 looper 7, 140 — 142 maggot . 131 — 135 webworm, imported ..142 — 144 worm, cross-striped 140 imported 136 — 139 Cantharis nuttalli 118, 119 Carbolic-acid emulsion .37, 108, 132 Carbon bisulphid, see Bisulphid of carbon Cameades messoria 242, 243 Carrot beetle 185 — 187 rust fly 176—179 Carrots, insects injurious to 184 — 188 Cassida bivittata 239 nigripes 239, 240 Caterpillars, miscellaneous ..60 — 62 Celatoria diabroticce 157 Celery caterpillar 179, 180 insects injurious to ..176 — 186 leaf-tyer 180—182 looper ..._ 182, 183 Centipedes, briefly defined 5 Cerotoma trifurcata 110, 111 Chcetocnema confinis 240, 241 denticulata 212 pulicaria 211 Chinch bugi false 150, 151 Chrysomelidae 62 — 66 Clean farming ....22, 158, 159, 167 Click beetles 80, 81 Cole crop insects 131 — 154 Coleoptera (beetles), defined 6 Collecting insects, see also hand- picking 27 Compsomyia^macellaria, figured ...8 Control of insects, natural ele- ments in 11 — 15 Cooperation in control of in- sects 23 — 25 Copidosoma truncatella 142 Copper arsenite 32 Coptocycla bicolor 238 guttata .••;.... 238, 239 Corimelcena pulicaria 183 259 26o INDEX PAGE Corn bill-bugs 195 — 199 cutworm 210, 211 ear worm 113, 207, 208 insects injuring 189 — 212 root-aphis 189, 190 root-worms 191 — 195 stalk-borer, larger 201 — 204 stalk-borer, smaller ..204—207 Corrosive sublimate 37, 38 Covering, cloth 27, 28 Cowpea weevil 104 — 106 Crioceris asparagi 93 — 96 12-punctata 96, 97 Crop pests, general 49 — 91 rotation, see Rotation Crustacea, briefly defined 4 Cucumber beetle, striped ..156 — 159 twelve-spotted ..159, 191 —193, 218 flea-beetle 218 insects injuring 155 Cultivation methods ..21, 132, 133, 138, 139 Cultural methods, see Farming methods Currant leaf hopper 85 Cutworm, corn 210, 211 dark-sided 246 spotted 210, 211 variegated 53, 54 Cutworms ..49—59, 113, 124, 145, 210, 211, 242, 243, 246 Cylas formicarius 235, 236 Depressaria heracliana ....187, 188 Diabrotica longicornis ....194, 195 12-punctata 159, 191—193 figured xiii vittata 156 — 159 Diacrisia virginica 60 Diamond-back moth 144, 145 Diaphania hyalinata 173 — 175 nitidalis 1 71 — 1 73 Diatrcea saccharalis 201 — 204 Diedrocephala versuta . . 117 Diptera, defined 8 Disking 21 Disonycha xanthomel&na ..121, 122 Diversified agriculture 20 Domestic animals, destroying insects 79 "Drill-worm" 191 Driving insects 68, 159 Eggplant flea-beetle 219 Elasmopalpus lignosellus ..204 — 207 Empoasca Aavescens 85 Entomology, value of knowledge of 1-^3 Epicauta letnniscata 67, 68 maculata 68 marginata 124 pennsylvanica 220, 221 vittata 67 Epidapus scabiei 226 — 228 Epilachna borealis 160, 161 corrupta 109, 110 Epitrix cucumeris 217 — 219 fuscula 219 parvula ..219, 220 PAGE Eubadizon schizoceri, figured ..241 Eudamus proteus 112 Euphoria inda 209, 210 Euschistus variolarius, figured ..10 Eutettix tenella 128 Euthrips tritici, figured 10 Euxoa messoria 246 Evergestis rimosalis 140 Fall army worm 56 — 59 harrowing 170 plowing 21, 78, 82 Farming methods, to prevent insect injury ..16 — 25, 65, 66 Feltia annexa 53 Fertilizers, danger from organic. 108 mineral 108 "Fire bug" 149 Fish-oil soap 38 Flea-beetles ..63—66, 121, 122, 146 —149, 211, 212 Flies defined . 8 Formalin 38 Fruit-chafer, brown 209, 210 Garden flea-hopper 118 webworm 61, 62 Gas lime 34, 35 Granulated cutworm 53 Grasshoppers 69 — 73, 127 Greasy cutworm 52 Ground beetle, fiery, figured ....12 Gumbo, insects injuring 249 Hair-streak, gray 113, 114 Halticini 63—66 Halticus uhleri 118 Hand-picking ..27, 56, 108, 109, 132 Harlequin cabbage bug ....148 — 150 Heliophila (Leucania) unipuncta. 59 Heliothis obsoleta 113, 207, 208, 233 234 Hellebore' 35, 108, 135 Hellula undalis . 142 — 144 Hemiptera, defined 9 Heteroptera, defined 9 Hexapoda (insects) defined 5 Hippodamia convergens, figured ..6 Homoptera, defined 9 Honey-dew 84, 85 Hopper-dozers 27 Hot water, as insecticide. .38, 39, 138 Hymenoptera, defined 8 Insecticide apparatus 43 — 47 Insecticides 30 — 39, 78 applying 47 proprietary 42, 43 Insects, injurious, determina- tion of xii injury, manifestations of x life history of 2 classification 3 — 6 natural elements in control of 11—15 predaceous 12 useful 14 Inspection, farm 22, 23 Tune beetles 73 — 79 Kerosene and sand 108 emulsion ..16, 37, 65, 116, 138, 167, 178 INDEX 26l PAGE Knapsack sprayer 44 Lace-wing fly, figured 1 1 Lachnosterna arcuata 76 cribrosa 77 farcta 77 fusca 76 Ladybird, convergent, figured ....6 spotted 95 Ladybirds 13 Laphygma exigua 125 frugiperda ..56—59, 208, 209 Leaf-beetles 62—66, 121—124 -hoppers .85—87, 117, 127, 128 -miners 127, 153, 154 Lebia grandis 13, 217 Lepidoptera, defined 7 Leptinotarsa decemlineata .214 — 217 Lettuce earth-louse 249 insects injurious to ..248, 249 Ligyrus gibbosus 185 — 187 Lime 34 Lixus concavus 247 Locusts 69 — 73 London purple 32 Loxostege similalis 61, 62 sticticalis 125, 126 Lygus pratensis 87, 88 Macrobasis unicolor 119 Mancasellus brachyurus, figured ..4 May beetles 73 — 79 Mealy-bugs 243 Mechanical methods of destroy- ing insects 26 — 29 Megilla maculata 95 Melanoplus differential's 71 femur-rubrum 70 spretus 9, 70, 71 Melanotus communis 80, 81 Melittia satyriniformis ....168 — 171 Meloidce 66 — 69 Melon aphis 85, 165 — 168 caterpillar 173—175 insects injuring 155 — 175 Millipedes, briefly defined 5 Milyas cinctus, figured 12 Mites, defined 4 Monocrepidius vespertinus, fig- ured 212 Monoxia consputa 123 puncticollis 122, 123 Moths, defined - 7 Murgantia histrionica ....148 — 150 Myriopoda, defined 5 Natural elements in control of insects 11 — 15 Nectarophora cucurbitce . . . 165 destructor 114 — 117 erigeronensis 229 Negro bug, little 183 Neuroptera, defined 10 Nicotine extracts and powders . .41 Noctua _ clandestina 51 c-nigrum 210, 211 Nozzles, spraying 47 Nysius^ angustatus 150, 151 minuius 151 Ogdoconta cinereola 113 PAGE Okra, insects injurious to 249 Oncometopia undata 249 Onion fly, black 245 insects injuring 244 — 246 maggot, imported 245 thrips 89, 90 Orthoptera, defined 9 Papaipema nitela 199 — 201 Papilio polyxenes 179, 180 Parasites, useful 14 Paris green 30 — 32 Parsley, insects injuring ..184 — 188 Parsnip leaf-miner 184, 185 webworm 187, 188 Parsnips, insects injuring .184 — 188 Pea aphis 114 — 117 moth ill, 112 weevil 100 — 102 Peas, insects injuring ....100 — 119 Pegomya brassicce 131 — 135 cepetorum 245 fusciceps 106—109, 135 Pemphigus beta 129 Pepper, insects injuring 250 Peridroma saucia 53, 54 Phoedon ceruginosa 147 Phlegethontius quinquemaculata 229—232 sexta 232, 233 Phlyctcenia ferrugalis 180 — 182 Phthorimaa operculella ...224 — 226 Phyllotreta pusilla 147, 148 vittata 146, 147 Physopoda, defined 10 Pickle worm 171 Pie-plant, insects injuring. .246 — 248 Plant-bug, brown, figured 10 tarnished, figured 11 Plant-bugs ..10, 83, 87, 88, 117, 118, 127, 128, 148—151 Planting to avoid insect injury 17, 158 Plant-lice, see Aphis and Aphides Plusia simplex 182, 183 Plutella maculipennis 144, 145 Podisus maculiventris 95 Poisoned baits 54, 83 Poisons, contact 36 — 39 _ stomach 30, 35 Polistes bellicosus, figured 5 Pontia napi 139, 140 protodice 139 rapes 136 — 139 Potato beetle, Colorado ..214 — 217 flea-beetle 217—219 insects injuring 213 — 228 scab gnat 226 stalk weevil 221—224 tuber worm 224 — 226 Potherb butterfly 139, 140 Preventives ■ ... 16, 78, 79 Proprietary insecticides 42, 43 Protection of plants 55 Pruning, as insect remedy 28 Psilarosce 176—179 Psylliodes punctulata 248 Pteromalus puparum. 14, 15, 137, 138 Pyrethrum..39, 40, 65, 138, 159, 167, 262 INDEX PAGE Red-legged locust 70 Red spider . . 91 Repellents 28, 29 Rhizobius lactucce 249 Rhopalosiphum dianthi ....151, 214 solani 229 Rhubarb curculio 247 flea-beetle 248 insects injuring 246 — 248 Rocky mountain locust ..9, 70, 71 Root-maggots . „ 131 — 135 Rotation, crop 19, 79, 82, 83 Salsify, insects injuring 250 Scaptomyza Haveola 153, 154 Scheele's green 32 Schizocerns ebenus 241 privatus 241, 242 Screw-worm, figured 8 Seed-corn maggot . . . 106 — 109, 135 Semasia nigricana Ill, 112 Sharpshooter, waved 249 Sigalphus curculionis 223 Soap, insecticide 38, 65, 167 Soldier-bug, bordered 12, 95 spined 95 Sowing, late 178 Sphenophorus aqualis 198 callosus 195 maidis 196, 197 zea> 197, 198 Spinach flea-beetle 121, 122 insects injuring 120 — 130 Sprayer, knapsack 44 Spraying 36, 37, 43 — 47 Spraying apparatus 43 — 47 Spring plowing 1 70 Squash bug 161 — 164 ladybird 160, 161 -vine borer 158 — 171 Stalk-borer, common 199 — 201 Stiretrus anchor ago 95 Suffocation, insecticides which kill by 39 — 42 Sugar-beet leaf-hopper 128 Sulphur 41, 42 Sweet corn, insects injuring 189—212 Sweet-potato beetle, two-striped. 239 flea-beetle 240, 241 insects affecting 235 — 243 root-borer 235, 236 sawflies 241, 242 tortoise beetles 236 — 238 Syrphus ribesii, figured 13 Systena . blanda 63, 64 tceniata 64, 65 Tarnished plant-bug 1, 87, 88 Tarred paper cards 133 — 135 Tetranychus bimaculatus 91 Thecla melinus 113, 114 Thousand-legged worms 5 Thrips 10, 89—91 tabaci 89, 90 tritici 90, 91 Tiphia inornata 78 Tobacco, as insecticide 40 flea-beetle 219, 220 Tomato fruit worm 233, 234 insects injurious to ...229 — 234 worms 229 — 233 Tortoise beetles 237 — 240 Trap crops .138, 139, 158, 159, 170 Trapping insects 28 Trichobaris trinotata 221 — 224 Trichopoda pennipes 163, 164 Tritoxa flexa 245 Turnip flea-beetle, striped .146, 147 leaf-miner, imported ..153, 154 Tychea brevicornis 130 Variegated cutworm it 53, 54 Vermorel nozzle 47 Water-cress leaf-beetle 147 sowbug, illustrated 4 Whale-oil soap 38 Wheat thrips 90, 91 wireworm 80 White fly 175 White grubs 73—79, 130 Wireworms 79 — 83, 130, 212 W-marked cutworm 51 Yellow bear 60 STANDARD BOOKS PUBLISHED BY ORANGE JUDD COMPANY NEW YORK CHICAGO 439-441 Lafayette Street Marquette Building T)OOKS sent to all farts of the world for catalog price. 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The subject-matter includes a comprehensive and succinct treatise of wheat, maize, oats, barley, rye, rice, sorghum (kaflr corn) and buckwheat, as related particularly to American conditions. First-hand knowledge has been the policy of the author in his work, and every crop treated is presented in the light of individual study of the plant. If you have this book you have the latest and best that has been written upon the subject. Illustrated. 450 pages. 5^ x 8 inches. Cloth $1.75 The Forage and Fiber Crops in America By Thomas F. Hunt. This book is exactly what its title indicates. It is indispensable to the farmer, student and teacher who wishes all the latest and most important information on the subject of forage and fiber crops. Like its famous com- panion, "The Cereals in America," by the same author, it treats of the cultivation and improvement of every one of the forage and fiber crops. With this book in hand, you have the latest and most up-to-date information available. Illus- trated. 428 pages. 5% x 8 inches. Cloth $i-75. The Book of Alfalfa History, Cultivation and Merits. Its Uses as a Forage and Fertilizer. The appearance of the Hon. F. D. Coburn's little book on Alfalfa a few years ago has been a profit revela- tion to thousands of farmers throughout the country, and the increasing demand for still more information on the subject has induced the author to prepare the present volume, which is by far the most authoritative, complete and valuable work on this forage crop published anywhere. It is printed on fine paper and illustrated with many full-page photographs that were taken with the especial view of their relation to the text. 336 pages. 6 l / 2 x 9 inches. Bound in cloth, with gold stamp- ing. It is unquestionably the handsomest agricultural reference book that has ever been issued. Price, postpaid . . . $2.00 Clean Milk By S. D. Belcher, M.D. In this book the author sets forth practical methods for the exclusion of bacteria from milk, and how to prevent contamination of milk from the stable to the consumer. Illustrated. 5x7 inches. 146 pages. Cloth $1.00 Bean Culture By Glenn C. SeveY, B.S. A practical treatise on the pro- duction and marketing of beans. It includes the manner of growth, soils and fertilizers adapted, best varieties, seed selec- tion and breeding, planting, harvesting, insects and fungous pests, composition and feeding value ; with a special chapter on markets by Albert W. Fulton. A practical book for the grower and student alike. Illustrated. 144 pages. 5x7 inches. Cloth $0.50 Celery Culture By W. R. Beattie. A practical guide for beginners and a standard reference of great interest to persons already engaged in celery growing. It contains many illustrations giving a clear conception of the practical side of celery culture. The work is complete in every detail, from sowing a few seeds in a window-box in the house for early plants, to the handling and marketing of celery in carload lots. Fully illustrated. 150 pages. 5x7 inches. Cloth $0.50 Tomato Culture By Will W. Tracy. The author has rounded up in this book the most, complete account of tomato culture in all its phases that has ever been gotten together. It is no second- hand work of reference, but a complete story of the practical experiences of the best posted expert on tomatoes in the world. No gardener or farmer can afford to be without the book. Whether grown for home use or commercial purposes, the reader has here suggestions and information nowhere else available. Illustrated. 150 pages. 5x7 inches. Cloth. $0.50 The Potato By Samuel Fraser. This book is destined to rank as a standard work upon Potato Culture. While the practical side has been emphasized, the scientific part has not been neglected, and the information given is of value, both to the grower and the student. Taken all in all, it is the most complete, reliable and authoritative book on the potato ever published in America. Illustrated. 200 pages. 5x7 inches. Cloth $0.75 Dwarf Fruit Trees By F. A. Waugh. This interesting book describes in detail the several varieties of dwarf fruit trees, their propagation, planting, pruning, care and general management. Where there is a limited amount of ground to be devoted to orchard pur- poses, and where quick results are desired, this book will meet with a warm welcome. Illustrated. 112 pages. 5x7 inches. Cloth $0.50 Cabbage, Cauliflower and Allied Vegetables By C. L. Allen. A practical treatise on the various types and varieties of cabbage, cauliflower, broccoli, Brussels sprouts, kale, collards and kohl-rabi. An explanation is given of the requirements, conditions, cultivation and general management pertaining to the entire cabbage group. After this each class is treated separately and in detail. The chapter on seed raising is probably the most authoritative treatise on this subject ever published. Insects and fungi attacking this class of vegetables are given due attention. Illustrated. 126 pages. 5x7 inches. Cloth $0.50 Asparagus By F. M. Hexamer. This is the first book published in America which is exclusively devoted to the raising of aspara- gus for home use as well as for market. It is a practical and reliable treatise on the saving of the seed, raising of the plants, selection and preparation of the soil, planting, cultiva- tion, manuring, cutting, bunching, packing, marketing, canning and drying, insect enemies, fungous diseases and every require- ment to successful asparagus culture, special emphasis being given to the importance of asparagus as a farm and money crop. Illustrated. 174 pages. 5x7 inches. Cloth. . $0.50 The New Onion Culture By T. Greiner. Rewritten, greatly enlarged and brought up to date. A new method of growing onions of largest size and yield, on less land, than can be raised by the old plan. Thousands of farmers and gardeners and many experiment stations have given it practical trials which have proved a success. A complete guide in growing onions with the great- est profit, explaining the whys and wherefores. Illustrated. 5x7 inches. 140 pages. Cloth $0.50 The New Rhubarb Culture A complete guide to dark forcing and field culture. Part I — By J. E. Morse, the well-known Michigan trucker and originator of the now famous and extremely profitable new methods of dark forcing and field culture. Part II — Compiled by G. B. Fiske. Other methods practiced by the most experi- enced market gardeners, greenhouse men and experimenters in all parts of America. Illustrated. 130 pages. 5x7 inches. Cloth. . ' $0.50 Farm Grasses of the United States of America By William Jasper Spillman. A practical treatise on the grass crop, seeding and management of meadows and pastures, description of the best varieties, the seed and its impurities, grasses for special conditions, lawns and lawn grasses, etc., etc. In preparing this volume the author's object has been to present, in connected form, the main facts con- cerning the grasses grown on American farms. Every phase of the subject is viewed from the farmer's standpoint. Illus- trated. 248 pages. 5x7 inches. Cloth. . . . $1.00 The Book of Corn By Herbert Myrick, assisted by A. D. Shamel, E. A. Burnett, Albert W. Fulton, B. W. Snow, and other most capable specialists. A complete treatise on the culture, marketing and uses of maize in America and elsewhere, for farmers, dealers and others. Illustrated. 372 pages. 5x7 inches. Cloth. $1.50 The Hop — Its Culture and Care, Marketing and Manufacture By Herbert Myrick. A practical handbook on the most approved methods in growing, harvesting, curing and selling hops, and on the use and manufacture of hops. The result of years of research and observation, it is a volume destined to be an authority on this crop for many years to come. It takes up every detail from preparing the soil and laying out the yard, to curing and selling the crop. Every line represents the ripest judgment and experience of experts. Size, 5x8; pages, 300; illustrations, nearly 150; bound in cloth and gold; price, postpaid, $1.50 Tobacco Leaf By J. B. Killebrew and Herbert Myrick. Its Culture and Cure, Marketing and Manufacture. A practical handbook on the most approved methods in growing, harvesting, curing, packing and selling tobacco, with an account of the opera- tions in every department of tobacco manufacture. The contents of this book are based on actual experiments in field, curing barn, packing house, factory and laboratory. It is the only work of the kind in existence, and is destined to be the standard practical and scientific authority on the whole sub- ject of tobacco for many years. 506 pages and 150 original engravings. 5x7 inches. Cloth $2.00 Bulbs and Tuberous-Rooted Plants By C. L. Allen. A complete treatise on the history, description, methods of propagation and full directions for the successful culture of bulbs in the garden, dwelling and greenhouse. The author of this book has for many years made bulb growing a specialty, and is a recognized authority on their cultivation and management. The cultural direc- tions are plainly stated, practical and to the point. The illustrations which embellish this work have been drawn from nature and have been engraved especially for this book. 312 pages. 5x7 inches. Cloth. .... $1.50 Fumigation Methods By Willis G. Johnson. A timely up-to-date book on the practical application of the new methods for destroying insects with hydrocyanic acid gas and carbon bisulphid, the most powerful insecticides ever discovered. It is an indis- pensable book for farmers, fruit growers, nurserymen, garden- ers, florists, millers, grain dealers, transportation companies, college and experiment station workers, etc. Illustrated 313 pages. 5x7 inches. Cloth $1.00 Diseases of Swine By Dr. R. A. Craig, Professor of Veterinary Medicine at the Purdue University. A concise, practical and popular guide to the prevention and treatment of the diseases of swine. With the discussions on each disease are given its causes, symptoms, treatment and means of prevention. Every part of the book impresses the reader with the fact that its writer is thoroughly and practically familiar with all the details upon which he treats. All technical and strictly scientific terms are avoided, so far as feasible, thus making the work at once available to the practical stock raiser as well as to the teacher and student. Illustrated. 3x7 inches. 190 pages. Cloth $0.75 Spraying Crops— Why, When and How By Clarence M. Weed, D.Sc. The present fourth edition has been rewritten and reset throughout to bring it thoroughly up to date, so that it embodies the latest practical information gleaned by fruit growers and experiment station workers. So much new information has come to light since the third edition was published that this is practically a new book, needed by those who have utilized the earlier editions, as well as by fruit growers and farmers generally. Illustrated. 136 pages. 5x7 inches. Cloth $0.50 Successful Fruit Culture By Samuel T. Maynard. A practical guide to the culti- vation and propagation of Fruits, written from the standpoint of the practical fruit grower who is striving to make his business profitable by growing the best fruit possible and at the least cost. It is up-to-date in every particular, and covers the entire practice of fruit culture, harvesting, storing, mar- keting, forcing, best varieties, etc., etc. It deals with principles first and with the practice afterwards, as the foundation, prin- ciples of plant growth and nourishment must always remain the same, while practice will vary according to the fruit grower's immediate conditions and environments. Illustrated. 265 pages. 5x7 inches. Cloth $1.00 Plums and Plum Culture By F. A. Waugh. A complete manual for fruit growers, nurserymen, farmers and gardeners, on all known varieties of plums and their successful management. This book marks an epoch in the horticultural literature of America. It is a complete monograph of the plums cultivated in and indigenous to North America. It will be found indispensable to the scientist seeking the most recent and authoritative informa- tion concerning this group, to the nurseryman who wishes to handle his varieties accurately and intellingently, and to the cultivator who would like to grow plums successfully. Illus- trated. 391 pages. 5x7 inches. Cloth. . . . $1.50 Fruit Harvesting, Storing, Marketing By F. A. Waugh. A practical guide to the picking, stor- ing, shipping and marketing of fruit. The principal subjects covered are the fruit market, fruit picking, sorting and pack- ing, the fruit storage, evaporating, canning, statistics of the fruit trade, fruit package laws, commission dealers and dealing, cold storage, etc., etc. No progressive. fruit grower can afford to be without this most valuable book. Illustrated. 232 pages. 5x7 inches. Cloth , . $1.00 Systematic Pomology By F. A. Waugh, professor of horticulture and landscape gardening in the Massachusetts agricultural college, formerly of the university of Vermont. This is the first book in the English language which has ever made the attempt at a com- plete and comprehensive treatment of systematic pomology. It presents clearly and in detail the whole method by which fruits are studied. The book is suitably illustrated. 288 pages. 5x7 inches. Cloth , $1.00 Feeding Farm Animals By Professor Thomas Shaw. This book is intended alike for the student and the farmer. The author has succeeded in giving in regular and orderly sequence, and in language so simple that a child can understand it, the principles that govern the science and practice of feeding farm animals. Professor Shaw is certainly to be congratulated on the successful manner in which he has accomplished a most difficult task. His book is unquestionably the most practical work which has appeared on the subject of feeding farm animals. Illustrated. $ l / 2 x 8 inches. Upward of 500 pages. Cloth $2.00 Profitable Dairying By C. L. Peck. A practical guide to successful dairy man- agement. The treatment of the entire subject is thoroughly practical, being principally a description of the methods prac- ticed by the author. A specially valuable part of this book consists of a minute description of the far-famed model dairy farm of Rev. J. D. Detrich, near Philadelphia, Pa. On this farm of fifteen acres, which twenty years ago could not main- tain one horse and two cows, there are now kept twenty-seven dairy cattle, in addition to two horses. All the roughage, litter, bedding, etc., necessary for these animals are grown on these fifteen acres, more than most farmers could accomplish on one hundred acres. Illustrated. 5x7 inches. 200 pages. Cloth $0.75 Practical Dairy Bacteriology By Dr. H. W. Conn, of Wesleyan University. A complete exposition of important facts concerning the relation of bacteria to various problems related to milk. A book for the class- room, laboratory, factory and farm. Equally useful to the teacher, student, factory man and practical dairyman. Fully illustrated with 83 original pictures. 340 pages. Cloth. Modern Methods of Testing Milk and Milk Products By L. L. VanSlyke. , This is a clear and concise discussion of the approved methods of testing milk and milk products. All the questions involved in the various methods of testing milk and cream are handled with rare skill and yet in so plain a manner that they can be fully understood by all. The book should be in the hands of every dairyman, teacher or student. Illustrated. 214 pages. 5x7 inches $0.75 Rural School Agriculture By Charles W. Davis. A book intended for the use of both teachers and pupils. Its aim is to enlist the interest of the boys of the farm and awaken in their minds the fact that the problems of the farm are great enough to command all the brain power they can summon. The book is a manual of exercises covering many phases of agriculture, and it may be used with any text-book of agriculture, or without a text- book. The exercises will enable the student to think, and to work out the scientific principles underlying some of the most important agricultural operations. The author feels that in the teaching of agriculture in the rural schools, the laboratory phase is almost entirely neglected. If an experiment helps the pupil to think, or makes his conceptions clearer, it fills a useful purpose, and eventually prepares for successful work upon the farm. The successful farmer of the future must be an experimenter in a small way. Following many of the exercises are a number of questions which prepare the way for further research work. The material needed for performing the experiments'is simple, and can be devised by the teacher and pupils, or brought from the homes. Illustrated. 300 pages. Cloth. 5x7 inches. $1.00 Agriculture Through the Laboratory and School Garden By C. R. Jackson and Mrs. L. S. Daugherty. As its name implies, this book gives explicit directions for actual work in the laboratory and the school garden, through which agri- cultural principles may be taught. The author's aim has been to present actual experimental work in every phase of the subject possible, and to state the directions for such work so that the student can perform it independently of the teacher, and to state them in such a way that the results will not be suggested by these directions. One must perform the experi- ment to ascertain the result. It embodies in the text a com- prehensive, practical, scientific, yet simple discussion of such facts as are necessary to the understanding of many of the agricultural principles involved in every-day life. The book, although primarily intended for use in schools, is equally valuable to any one desiring to obtain in an easy and pleasing manner a general knowledge of elementary agriculture. Fully illustrated. 5^ x 8 inches. 462 pages. Cloth. Net . $1.50 Soil Physics Laboratory Guide By W. G. Stevenson and I. O. Schaub. A carefully out- lined series of experiments in soil physics. A portion of the experiments outlined in this guide have been used quite gen- erally in recent years. The exercises (of which there are 40) are listed in a logical order with reference to their relation to each other and the skill required on the part of the student. Illustrated. About 100 pages. 5x7 inches. Cloth. . $0.50 Farmer's Cyclopedia of Agriculture 3n jg y/ Compendium of Agricultural Sciefice and Praclice on Farm, Orchard and Garden Crops, and the Feeding and Diseases of Farm Animals : ; • ; *By EARLEY VERNON WILCOX, Ph.D and CLARENCE BEAMAN SMITH, M.S Associate Editors in the Office of Experiment Stations, United States Department of Agriculture This is a new, practical, and complete pres- entation of the whole subject of agricul- =S==« ture in its broadest sense. It is designed W^M for the use of agriculturists who de- sire up-to-date, reliable information on all matters pertaining to crops and stock, but more particularly for the actual farmer. The volume contains Detailed directions for the culture of every important field, orchard, and garden crop grown in America, together with descriptions of their chief insect pests and fungous diseases, and remedies for their control. It contains an ac- count of modern methods in feeding and handling all farm stock, including poultry. The diseases which affect different farm animals and poultry are described, and the most recent remedies sug- gested for controlling them. Every bit of this vast mass of new and useful information is authoritative, practical, and easily found, and no effort has been spared to include all desirable details. There are between 6,000 and 7,000 topics covered in these references, and it contains 700 royal 8vo pages and nearly 500 suberb half-tone and other original illustrations, making the most perfect Cyclopedia of Agricul- ture ever attempted. Handsomely bound in cloth, $3.50; half nhoroccc {-Very sumptuous), £4-.50. postpaid ORANGE JUDD COMPANY, < *1LSrU5«Jft" OCT 11 »w» /OBI II 100