SB 608 .C875 W4 Copy 1 The Insect Fauna of the Genus Crataegus A THESIS PRESENTED TO THE FACULTY OF THE GRADUATE* SCHOOL OF CORNELL UNIVERSITY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY BY WALTER HOUSLEY WELLHOUSE Reprinted from Cornell University Agricultural Experiment Station Memoir 56 Ithaca, N. Y. June 192.?. The Insect Fauna of the Genus Crataegus A THESIS PRESENTED TO THE FACULTY OF THE GRADUATE SCHOOL OF CORNELL UNIVERSITY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY BY WALTER HOUSLEY WELLHOUSE Reprinted from Cornell University Agricultural Experiment Station Memoir 56 Ithaca, N. Y. June 1922. y> 4^ By. ■ on CONTENTS PAGE The genus Crataegus 1046 Ecological summary 1047 The relation of Crataegus insects to apple, pear, and quince 1050 Biological notes on insects feeding on Crataegus, as observed by the writer from 1917 to 1920 1051 Acarina 1051 Tetranychidae 1051 Eriophyidae 1052 Ort hoptera 1054 Acridiidae 1054 Hemiptera 1054 Miridae ( Capsidae) 1054 Tingitidae 1056 Cicadellidae (Jassidae) 1061 Membracidae 1063 Aphididae 1063 Coccidae 1065 Thysanoptera 1066 Thrypidae 1066 Coleoptera 106C Elateridae 1066 Buprestidae 1066 Scarabaeidae 1066 Chrysomelidae 1067 Curculionidae 1068 Lepidoptera 1072 Papilionidae 1072 Saturniidae 1073 Arctiidae 1073 Noctuidae 1073 Notodontidae 1074 Lymantriidae 1075 Lasiocampidae 1075 Geometridae 1076 Sesiidae (Aegeriidae) 1076 Pyralidae 1077 Tortricidae 1077 Yponomeutidae 107S Elachistidae 1079 Lyonetiidae .' 1079 Cosmopterygidae 1080 Diptera 1080 Cecidomyiidae (Itonididae) 1080 Trypetidae 1085 Hymenoptera 1086 Tenthredinidae 1086 1041 1042 Contents PAGE Literature cited 1088 Catalog of insects injurious to Crataegus 1090 Acarina 1090 Orthoptera 1091 Odonata 1091 Hemiptera 1091 Thysanoptera 1 100 Coleoptera 1 100 Lepidoptera 1 108 Diptera ? 1129 Hymenoptera 1 131 Index of genera and species 1133 THE INSECT FAUNA OF THE GENUS CRATAEGUS THE INSECT FAUNA OF THE GENUS CRATAEGUS Walter H. Wellhouse This paper is submitted as a result of three years of study of the insects that feed on the plants belonging to the genus Crataegus. The writer's object at the time when the work was undertaken was primarily to learn, by collecting and rearing, what insects occur on the trees of this genus in central New York. As the interest in the work increased, it was decided to widen the field and make the list more complete by including the insects that other workers have found to be eaters of Crataegus. There are three older lists of insects feeding on Crataegus which have been helpful in the preparation of the present, catalog. Kaltenbach (1872) x gives a list of 104 European species, Packard (1890) gives 46 American species, and Felt (1906) gives 28 American species. With the ex- ception of these three lists, the material included in this paper is gathered from widely scattered references and from the writer's observations. Since food-plant indices are very commonly omitted from entomological writings, it is difficult to get a list of all the insects that feed on a plant. Such a list can be obtained only by scanning the pages of a multitude of papers containing biological notes on all orders of insects. Much of that kind of work has been done in the preparation of this catalog, but, since it has not been possible to see all papers that might contain accounts of insects feeding on Crataegus, the writer does not claim that his list is complete. The catalog contains 382 species, representing 9 orders and 55 families. They are distributed as follows: Acarina, 10 species: Thysanoptera, 1 species: Eriophyidae 7 Thrypidae 1 Phyllocoptidae 1 Coleoptera, 74 species: Tetranychidae 2 Elateridae 3 Orthoptera, 4 species: Buprestidae 6 Gryllidae 1 Scarabaeidae 4 Acridiidae 3 Ceratnbycidae 5 Odonata, 1 species : Chrysomelidae 12 Agrionidae 1 Curculionidae 40 Hemiptera (including Homoptera), 8 I Ipidae (Scolytidae). 2 species : Anthribidae 1 Miridae (Capsidae) 12 Dermestidae 1 Tingitidae 4 Lepidoptera, 184 species: Membracidae 4 Papilionidae 2 Cicadellidae (Jassidaej In Nymphalidae 2 Psyllidae (Chermidae) 7 Pieridae 1 Aphididae 22 Lycaenidae 3 Coccidae 17 Sphingidae 3 'Dates in parenthesis refer to Literature Cited, page 1088. 1045 1046 Walter H. Wellhouse Lepidoptera {continued): Lepidoptera {continued): Saturniidae 3 Yponomeutidae 7 Arctiidae 3 Gelechiidae 6 Noctuidae 27 Elachistidae 5 Notodontidae 6 Gracilariidae 12 Lymantriidae 7 Glyphipterygidae 2 Lasiocampidae 10 Nepticulidae 11 Geometridae 27 Cosmopterygidae 2 Drepanidae 1 Lyonetiidae 4 Nolidae 1 Diptera, 16 species: Psychidae 1 Cecidomyiidae (Itonididae) 15 Limacodidae 1 Trypetidae 1 Cossidae 1 Hymenoptera, 8 species: Sesiidae (Aegeriidae) 3 Tenthredinidae . . 7 Pyralidae 3 Chalcididae 1 Tortricidae 30 The catalog includes insects that have been taken on the Crataegus trees in five continents. The number of species reported from each continent is as follows: North America, 213 species; Europe, 203; Asia, 88; Africa, 11 ; Australia, 8. All but 45 of the North American species are believed to be distinct from those of the Old World. A single Australian species is distinct from those of other continents. The insects recorded from Asia and Africa are found also in Europe. It will be noticed that the mites, which have similar habits, are included with the insects in this paper. Some helpful references to entomological notes concerning each species have been included in the catalog, which is intended as an aid to other workers who are investigating the insects of our deciduous fruit trees and related plants. Grateful acknowledgment is made to Professors Glenn W. Herrick and James G. Needham, of the Department of Entomology at Cornell Uni- versity, under whose direction the work was done and whose kindly criti- cisms and suggestions are appreciated; also to Dr. W. T. M. Forbes, Dr. Edith M. Patch, Chas. W. Leng, Dr. P. B. Lawson, Professor Z. P. Metcalf, Dr. H. H. Knight, Professor Carl J. Drake, Dr. E. P. Felt, and Henry Dietrich, who have kindly aided in the determination of species; to Dr. K. M. Wiegand, who has kindly aided in the determina- tion of species of Crataegus; and to Miss Lela G. Gross for able editorial assistance. THE GENUS CRATAEGUS Crataegus is the name of a group of trees and shrubs commonly known by their sharp thorns, white flowers (pink or red in a few cultivated varieties) in May, and red' or yellowish fruit like minature apples in autumn. It is an ancient Greek name derived from kratos (strength), and was applied to the plants of this genus because of the hardness and durability of the wood. The Insect Fauna of the Genus Crataegus 1047 Among the popular names by which the genus is known most commonly are the following: hawthorn, thorn apple, red haw, white thorn, and thorn, in America; hawthorn and may, in England; aubepine, in France (snellier, by French Canadians); Weissdorn, in Germany; spinalba, in Italy. , As the name hawthorn seems to be the one most commonly used by English- speaking peoples, the writer has used it in this paper to represent .all species of Crataegus. The genus is placed by many botanists in the family Rosaceae. Other botanists have divided the Rosaceae group and formed an apple family, Malaceae, in which Crataegus is included along with Malus, Pyrus, Cydonia, Mespilus, Sorbus, Amelanchier, Aronia, and Eriobotrya.. The determination of species of Crataegus is as great a taxonomic problem to botanists as the determination of the parasitic Hymenoptera is to entomologists. During the first ten years of this century about one thousand species of Crataegus were described in North America. Many of them are now regarded as hybrids and varieties, -and 'a still further reduction of species is in progress. This taxonomic uncertainty makes it impossible in many cases to recognize specific hosts for th# insects that feed on the hawthorns. Crataegus is distributed over most of the temperate parts of the North- ern Hemisphere. The genus is not indigenous in the Southern Hemis- phere except in America, where it follows the unbroken mountain chain through the Tropics and grows in the Andes Mountains. It is found as far north as Newfoundland, Norway, and Sweden, and extends south- ward to the Mediterranean borders of Africa and Asia Minor. The European species have been introduced into Australia and other Europsan colonies in the Southern Hemisphere for cultivation. Most species of hawthorns seem to thrive in any well-drained soil which is not acid and where rainfall is sufficient for the growth of forest trees, while a few species thrive in acid soils also. They are usu- ally long-lived trees, and individuals 0113 hundred years old are not uncommon. Distribution is effected largely by means of birds and mammals, which eat the ripe fruits and carry the seeds in their digestive tracts to other communities. Within the same community, thickets are commonly formed from the new stems which grow from the roots of a single tree. Wherever the roots become exposed to light, as by washing on hillsides, a new stem may grow and a tree be formed from it. ECOLOGICAL SUMMARY The ecological relations of the hawthorns to their insect fauna may be summarized in a general way very briefly. The two basic needs of an insect which it is possible for a host plant to supply are food and shelter. The hawthorns furnish both food and shelter. 1048 Walter H. Wellhouse They furnish food for nearly all of the insects studied. A few excep- tions, such as the snowy tree cricket (Oecanthus niveus) and the damsel fly Lestes viridis, procure their food elsewhere and use the hawthorn branches merely to shelter their eggs from the weather and their enemies. Every part of the tree furnishes food for some species of insect, as may be seen from the following outline: Trunk and branches •. 40 species A. External feeders (scales, aphids, and ethers), 19 B. Internal feeders (borers), 21 Roots (aphids) 1 Thorns (weevils) 1 Leaves 292 A. External feeders (miscellaneous), 235 B. Miners (tineids, weevils, sawflies), 37 C. Gall makers (aphids, mites, cecidomyiids), 20 Flowers (thrips, maggots, caterpillars, beetles, and others) 12 Fruit (caterpillars, bugs, maggots, grubs) 30 The other basic need of insects which a host plant may supply is shelter. Most of the insects included in this paper are sheltered to some extent by the hawthorn, although the completeness of the shelter varies with the habits of each species of insect. Some are protected only by their position on the surface of the tree. Others are partially sheltered in rolled leaves, bark crevices, and the like. Still others are securely housed within the plant tissues. The degree of shelter secured by those species living externally on the surface of the plant varies so greatly and so gradually that no distinct lines of division can be drawn in so general a statement as this. The more distinct groups of internal feeders (borers, leaf miners, and gall makers) are indicated above and are distinguished from the external feeders, which receive less complete shelter. The fact that so many species of insects feed at the expense of the haw- thorns suggests the idea that these trees are in danger of extinction. Such is not the case, however, for the hawthorns when not weakened by drought or flood are very hardy, long-lived trees. Some indications as to why they so successfully withstand the feeding of the insects may be seen from a study of the following data, which are based on statistics given in the last sections of this paper: Approximate Feeding Period of Hawthorn Insects Species Species March 11 August 117 April 54 September 124 May 190 October 80 June ... 232 November 23 July 131 Time of feeding unknown 58 Food Plants of Hawthorn Insects Food plants restricted to Crataegus 57 species Food plants including other related or associated groups 325 species The Insect Fauna of the Genus Crataegus 1049 It will be noticed that there is a direct correspondence between the. time of feeding of the insects and the time of growth of the trees. The greatest number of species feed during May and June, when the trees make their greatest growth. The number decreases slightly during July and August, at the time when droughts frequently check tree growth, and then it increases slightly in September, at the time when fall rains often cause a new growth. This relationship between the period of growth and the time of feeding seems to be one of Nature's adjustments for maint ining balance. The fact that a large majority of the insects feed on other host plants also, lessens the danger of destruction of the hawthorns and is another of Nature's provisions for maintaining balance. There are, of course, many other factors that tend to lessen the insect injury to the trees, such as the interrelations of the insects with their parasites and preye.rs, but so little is known about them that the writer makes no attempt to discuss them. A host of bees, flics, and beetles visit the blossoms in quest of pollen and nectar. The winter buds in some species of hawthorn become coated with a sticky exudation, which attracts insects emerging in late winter, such as the stone flies and the chironomids. These transient members of the Crataegus fauna have been omitted from consideration in this paper. A list of insects that visit the blossoms is given by Knuth (1908). In the preparation of the catalog of hawthorn insects it became noticeable that some of the species which have more than one host plant have chosen only closely related hosts, such as the apple, the pear, or the medlar, while many others have chosen their hosts from plants that grow in the same communities regardless of close botanical relationship. A study of these combinations of hosts and the habitats in which they grow has led the writer to believe that the hawthorns are members of at least five different plant communities, which may be described as follows: 1. Open woods. In woodlands where the growth habit of the taller trees permits sunlight to reach the ground so that an undergrowth may develop, such as that in a forest of oak, hickory, and elm, Crataegus is commonly found along with Corylus, Rhamnus, Carpinus, Prunus spinosa, and the like. 2. Deforested areas. Where a shrubby growth has sprung up after the destruction of a forest, numerous thorny forms such as Crataegus, Rubus, Berberis, and Prunus spinosa are frequently found. 3. Grazing lands. Hillsides or valleys where the soil is uncultivated and cattle are pastured are frequently dotted with Crataegus, Rosa, and crab apple, which because of their thorns can continue to thrive and outgrow the ('anger of being eaten by the cattle. 4. Stream banks. Just back of the willows and alders on moist alluvial soil beside streams, Crataegus grows to its greatest size and is associated with birch, willow, alder, and poplar. 5. Fence rows. Where shrubs are allowed to grow up along the fences, Prunus virginiana, Crataegus, wild plum, and wild cherry are frequently found closely associated. In each of these five communities insects will be found which feed on the various plants of the community. For example, Psylla malt Schmid. 1050 Walter H. Wellhouse feeds on Crataegus, Malus, Sorbus, Quercus, Ulmus, and Corylus, which may all be found in the open-woods community, as may the host plants of the flat-headed apple-tree borer, Chrysobothris femorata Fabr. On the other hand, the leaf beetle, Cryptocephalus bipunctatus Linn., feeds near the streams on such plants as Salix, Betula, Crataegus, and Corylus, and Agrilus vittaticollis Rand, is found along the fence rows on Crataegus, Prunus virginiana, and Amelanchier. No very distinct lines can be drawn between the members of these communities, since many of the plants and insects belong to more than one community. THE RELATION OF CRATAEGUS INSECTS TO APPLE, PEAR, AND QUINCE A more complete knowledge of the insects that feed on Crataegus is of considerable importance as an aid in the control of insect pests of the cultivated commercial fruits. It has for many years, since the days of Walsh and Riley, been recognized by entomologists as the original native host plant of a number of important insect pests which now attack the apple, the pear, and the quince in the northeastern section of the United States. In all probability new pests must be expected to attack the culti- vated fruits in the future as the population of the country increases, since as a consequence less uncultivated land will remain where the insects may feed undisturbed on their natural hosts. The. main commercial fruits of the United States, such as the apple, the pear, the quince, and the cherry, are natives of the Old World and have been imported by man into America. With them were imported a number of foreign insects, such as the codling moth, the bud moth, and the sinuate pear borer, which continued to feed on them in this country. Many of the pests now destructive to these fruits, however, are native to North America and are not found in the Old World. Before the extensive plant- ing of the imported fruits these insects must have fed on native plants. Among the most numerous of the native plants which are similar to the apple, the pear, and the quince are those of the genus Crataegus, and the members of this genus are widely distributed throughout many of our commercial fruit districts. A young orchard which is set in the midst of hawthorns may be ruined in a few years by the insects that migrate to it from the surrounding trees. Well-established orchards may suffer from the attacks of new pests when- ever there is a failure of the crop, of wild haws or a clearing of the land occupied by hawthorns so that their natural guests must seek other hosts. It is commonly known among entomologists that the apple maggot, Rhagoletis pomonella, was originally a hawthorn insect and that after the apple had been cultivated in North America for many years this insect selected the larger, juicier fruit of the apple for its home. It is still found in the haws but is now known as an apple pest. The Insect Fauna of the Genus Crataegus 1051 The apple redbug, Heterocordylus malinus, is another hawthorn insect which has adopted the apple. It was formerly believed that the false apple redbug, Lygidea mendax, was also originally a hawthorn insect, but the observations of Cushman (1916), as well as those of the writer, indicate that L. mendax is a wild-crab insect and does not feed extensively on hawthorns. The quince curculio, Conotrachelus crataegi, is a very common feeder in haws which has occasionally injured quinces seriously and has thus gained its common name. Likewise the lesser apple worm, Laspeyresia prunivora, has gained its common name because of occasional migrations from hawthorn to apple. Baker (1915:10) considers the woolly apple aphis, Eriosoma lanigera, to have been originally an elm-Crataegus feeder which has adopted the apple and traveled around the world with it. The woolly aphis is undoubt- edly common on hawthorns. Numerous other native American insects that feed on apple, pear, or quince are included in the catalog of hawthorn feeders beginning on page 1090. The possibility that foreign hawthorn insects may be imported and become pests in North America should also be considered. When intro- duced into a new environment away from their natural checks, these may become more important here. Recent examples of this are three small moths imported from Europe — the apple and thorn leaf skeletonizer, Simaethis pariana; the hawthorn ermine moth, Yponomeuta padellus; and the lesser bud moth, Recurvaria nanella. These have attracted the attention of economic entomologists in North America as apple and cherry pests, while in Europe they feed commonly on hawthorns. Since the catalog of hawthorn insects included in this memoir lists their food plants and the continents where each species occurs, further examples of foreign hawthorn insects that are now in North America may be found there. biological notes on insects feeding on crataegus, as observed by the writer from 1917 to 1920 2 Acarina Tetranychidae telarius Linn., Tetranychus (Red spider) The leaves of all species of Crataegus observed showed attack by Tetranychus telarius. The European hawthorns, however, seem to be more often severely injured by these mites than the native species. The 2 The insects are grouped according to order and family, and arranged alphabetically by species within the family. 1052 Walter H. Wellhouse injury is severest in warm, dry periods. The leaves at first become grayish, due to the presence of a fine white web and the cast skins of the mites attached to them. Later they turn brown and their margins curl toward the surface on which the mites have fed. The adults hibernate among the fallen leaves and a few were found in bark crevices on the trunk in April. The tiny, round, white eggs are laid on the leaves. The mites breed continually on the leaves from June to October. Eriophyidae Eriophyes sp. No. 1 (Hawthorn serpentine gall of Jarvis) The species of Eriophyes here described produces long, green or red, serpentine galls confined to the space between two of the larger veins and extending from the midrib toward the margin of the leaf (fig. 102). The Fig. 102. leaves of craetaegus punctata showing serpentine galls produced by eriophyes sp. no. 1 gall consists of a wavy projection on the upper side of the leaf and a wavy incision on the lower side. In cross section the leaf appears convoluted, with the galls projecting upward as loops or pockets in which the mites The Insect Fauna of the Genus Crataegus 1053 live (fig. 103). The leaf does not become thickened in these galls. The galls become extremely abundant on some trees, so that almost every leaf is deformed. The mites seem to prefer the shady branches of trees, rather than those in bright sunlight. They become most abundant during August, when the galls are swarming with the microscopic white mites. The galls were found most abundantly on Crata- egus punctata, but they were Fig. 103. cross section of a Crataegus leaf, found also on C. pruinosa through three serpentine galls and other native hawthorns. Eriophyes sp. No. 2 (Hawthorn marginal gall) Galls very similar to those of Eriophyes gonioihorax Nal., which are found on hawthorns in Europe, are produced by Eriophyes sp. No. 2. The margin of the leaf is curled tightly downward for a dis- tance of two centimeters or more (figs. 104 and 105), and the curled margin is paler green than the rest of the leaf. The mites live within the curl. This gall is not very common about Ithaca, but was found in a few cases on Crataegus coccinea. Eriophyes sp. No. 3 (Thorn leaf pouch gall) Many small, pale green pouches, standing on the upper side of the leaf and opening beneath the leaf by a small slit, are caused by microscopic white mites which live within the pouches. The galls vary in size and shape, but are generally about two millimeters high and are rounded on top (figs. 106 and 107). They may be found at any place on the leaf except on the larger veins. They are fairly common on Crataegus punctata but are not so abundant as the serpentine galls. Fig. 104. hawthorn marginal galls sssssssgsss Fig. 105. cross section through curled edge OF LEAF 1054 Walter H. Wellhouse Orthoptera Acridiidae atlanis Riley, Melanoplus bivittatus Say, M. femur-rubrum De Geer, M. The common grasshop- pers Melanoplus atlanis, M. bivittatus, and M. femur-rubrum sometimes leave their herbaceous host plants to feed on the foliage of the lower branches of hawthorn trees. The older nymphs and adults have been observed feeding in August and September. They feed irregularly on the leaves, sometimes eat- ing the entire leaf and sometimes eating only the apex or one side of it. Hemiptera Miridae (Capsidae) communis Knight, Lygus One adult of Lygus communis was taken on June 21 and four were taken on August 2, puncturing the leaves of Crataegus punctata. dislocatus Say, Horcias A few adults of Horcias dislocatus were found feeding on leaves of Cra- taegus punctata in June. They are black, rather stout, and 6 millimeters long. malinus Reuter, Heterocordylus (Dark apple redbug) Nymphs and adults of Het- erocordylus malinus are very common'on native" hawthorns, where their'red color and rapid running over the branches make them very conspicuous. The young nymphs begin to appear about April 15, when Fig. 106. thorn leaf pouch galls Fig. 107. CROSS SECTION THROUGH POUCH GALL A THORN LEAF The Insect Fauna of the Genus Crataegus 1055 the blossom clusters have just begun to separate and before the blossoms show pink. They puncture the leaves and the tender twigs but do not cause any noticeable injury. After the fruit sets they feed on the fruit also and cause very slight dimples where they puncture it. They become adult in late May and early June, and begin ovipositing in the twigs about June 15. The egg is deposited in a small slit mad 3 with the beak at the base of a young twig. Adults were found on the trees until late July. mendax Reuter, Lygidea (Bright apple redbug) A few nymphs of Lygidea mendax were found feeding on the leaves and fruit of Crataegus in late April and in May. They are not so common as Heterocordylus malinus. In the warm laboratory the eggs hatched on March 27 on Crataegus punctata twigs, but no nymphs were found in the field until the blossoms were opening on April 25. Adults were found from June 2 to August 14. One adult in a breeding cage oviposited on June 19 in a twig of Crataegus crus-galli. She chose a year-old twig, drilled a hole through the bark at the base of the twig, and then, turning about, thrust an egg into the cavity. ornatus VanD., Orthotylus A few adults of Orthotylus ornatus were found feeding on the leaves of Crataegus pruinosa in June. They are brownish, spotted, slender, and 5.5 millimeters long. ostryae Knight, Lygus A few adults of Lygus ostryae were taken puncturing the leaves of Crataegus punctata in late June. They are pale yellowish brown, and are otherwise similar in appearance to the tarnished plant bug. pellucida Uhl., Diaphnidia The pale green nymphs of Diaphnidia pellucida are rather numerous on the foliage of Crataegus punctata during late May and early June. They run rapidly over the branches when disturbed, and feed on the leaves and tender twigs. Adults appeared from June 10 to June 15 in rearing cages in the laboratory, and others were found in the field on June 18. They are delicate, slender, pale green, and about 4 millimeters long. pratensis Linn., Lygus Adults of Lygus pratensis which have lived through the winter are some- times found puncturing the buds of Crataegus in April, as soon as the buds show green, and a few were found puncturing the young fruit in late May. univittatus Knight, Lygus Adults of Lygus univittatus are rather common during late May and June, puncturing the leaves and fruit of native hawthorns. They resemble L. communis very closely, but are generally paler. 1056 Walter H. Wellhouse Tingitidae bellula Gibson, Corythucha (Plates LXXII and LXXIII) Although the original description of Corythucha 'bellula was published but recently (Gibson, 1918), the species seems to be fairly common where its host plants occur, and it has probably been confused with C. cydoniae by earlier observers who must have seen it on the hawthorns. It has been found by Drake in Ohio and by Griddle in Manitoba. The host plants include those species of Crataegus that have hairy leaf veins, and also Alnus incana and Ribes oxyacanthoides. The writer has found the insect breeding in abundance on Crataegus neofluvialis and to some extent on C. albicans and C. punctata. The hawthorns with smooth leaves, such as C. pruinosa, C. crus-galli, and C. oxyacantha, even when their branches were intermingled with thos? of trees that were badly infested, revealed no nymphs nor eggs. In a large thicket of C. neofluvialis trees near the Cornell University campus, the leaves were so discolored by the end of July that they attracted attention several hundred yards away. By the middle of August the leaves were falling, and the branches were bare by September 1. No fruit matured on these trees. A few scattered trees of this species in other directions from the city were also badly infested. Individual trees of C. albicans and C. punctata showed an occasional branch badly infested and with leaves discolored. The injury is caused by the nymphs and the adults puncturing the under surface of the leaf and sucking the sap, producing at first a mottled effect due to the pale areas around the feeding punctures, while later the leaf turns brown and falls to the ground. Orna- mental plantings of Crataegus in parks and gardens are rendered unsightly and weakened by this injury. There are two generations annually at Ithaca. The first brood hatches in July from eggs laid in late May and in June, and the nymphs become mature in from twenty to twenty-five days. The second-brood eggs- are laid in late July and in August, and the adults appear in late August and in September. The adults of the second brood hibernate among the fallen leaves and in crevices of the bark. Many of them remain on the leaves on which they were feeding before the leaves fell. They appeared the last of May, and during early June were feeding on the new Crataegus leaves. As a rule only one pair of adults was found on a leaf, and they remained feeding and ovipositing on that same leaf for several days. After emer- gence from the nymphal skin in September, the adults of the second brood continue feeding on the leaves until they fall, in late September or in October. The egg is subelliptical, with the basal end rounded and the apical end bent slightly to one side and capped with a rather broad cylindrical collar Memoir 56 Plate_LXXII CORY1HUCHA BELLULA 1, Adult. 2, Lateral view of hood and carina. 3, Tip of abdomen of female, with ovi- positor at rest. 4, Same with ovipositor exserted ; chitinized parts within body shown by dotted lines. 5, Ovipositor. 6, Tip of abdomen of male, with claspeis at rest. 7, Same with claspeis exserted. 8, Eggs in position among haiis in axil of leaf veins 1057 1058 Walter H. Wellhouse surmounted by a low cone with irregular ridges extending from base to apex. From the apex of this cone there arises in some cases a short, blunt prolongation, but often this is absent. The egg is without waxy covering over the chorion, which is smooth, unsculptured, and of a shining dark- brown color but somewhat lighter toward the base. The cap, or cone, is often whitish. The egg, exclusive of the apical prolongation of the cap, is 0.52 millimeter long, and 0.21 millimeter broad at its greatest width. The eggs are laid on the under surface of the leaf, in the axils formed by the midrib and its lateral branches. Although the female has a well- developed, sawlike, four-valved ovipositor, the eggs are not inserted into the leaf tissue. They are placed among the hairs on the veins and are in some cases glued together with an adhesive material. They are gen- erally laid in small groups, some groups containing as many as eighteen or twenty eggs; but occasionally they are laid singly. In counting the number of eggs on one hundred infested leaves the writer found an average of forty-nine eggs to a leaf. Occasionally a leaf had seventy- five or eighty eggs on it. The egg-laying period extends over several weeks, so that eggs, nymphs, and adults may be found at the same time in July and August. Eggs laid on June 2 hatched on July 9 and 10, while the eggs of the second brood, laid on July 29 and 30, hatched on August 15 and 16. This indicates an incubation period of about thirty-seven days in the cooler temperature of June, and eighteen days in July and August when the average temperature was higher. The conical egg cap is pushed up by the nymph as it begins to emerge from the egg still inclosed in the embryonic membranous sac. When about halfway out of the eggshell the nymph splits the membranous sac and slips it off over the head, leaving it with the egg cap on the outer end hanging out from the empty eggshell. After emerging and drying, the nymphs begin to feed at once in colonies near the eggshells. They molt five times, feeding from three to six days between molts, the earlier stages requiring three or four days while the later ones require five or six days. In molting, the cuticula breaks along the median dorsal line from the front of the head to about the second abdominal segment. The insect on emerging is limp, and is almost color- less except for the eye facets which are bright red. The body color soon darkens and the eyes a few hours later become black. During the fifth stage the nymph wanders about more freely over the leaf and in some cases goes to adjoining leaves. Descriptions of the nymphal stages follow. First stage. — ■ Length 0.5 mm., greatest width 0.15 mm. General shape an elongate ellipse, somewhat broader cephalad than caudad and more elongate than in the later stages. At first almost colorless but soon becoming dark brown. Beak 4-segmented and extending back to sixth abdominal segment. Antenna 3-segmented, the basal two segments being shorter than the third segment; basal segment without spines or hairs, second segment with Memoir 56 Plate LXX1II 7 YOUNG STAGES OF CORYTHUCHA BELLULA 1, Egg. 2, Egg after hatching. 3, First-stage nymph. 4, Second-stage nymph. .">, Third stage nymph. 6, Fourth-stage nymph. 7, Fifth-stage nymph 1059 1060 Walter H. Wellhouse a few short hairs, third segment with numerous long spines and hairs, some with rounded tip and conical base, others with pointed tip. Head with five prominent dorsal tubercles, two slightly separated just above base of beak, each bearing a round-tipped spine; one tubercle back of these on median line bearing two spines; two tubercles near posterior margin, widely separated and each bearing two spines. Pro- and mesothorax having lateral tubercles with a spine on each, and mesothorax having a pair of dorsal tubercles with one spine on each. Metathorax and first abdominal segment without spines. Legs armed with short, pointed hairs and two bent, sharp, terminal claws. Nine abdominal ssgments visible above, each of these except the first bearing on each lateral margin a tubercle surmounted by a round- tipped spine; two dorsal tubercles on second, fifth, sixth, and eighth abdominal segments, those on second and eighth segments bearing one round-tipped spine each, and those on fifth and sixth segments bearing two spines each; tenth abdominal segment visible from a lateral or ventral view, this segment bearing no spines nor hairs; minute awl-shaped spinules over dorsal surface, especially on large tubercles of fifth and sixth abdominal segments and on thorax. (Plate LXXIII, 3.) Second stage. — Length 0.68 mm., greatest width 0.27 mm. Body broader in proportion to its length than in first stage; dark brown in color, with numerous minute spinules over dorsal surface, covering it much more completely than in first stage. Additional small spines on both dorsal and lateral tubercles, and the round-tipped spines present before having a slightly longer conical base in this stage. (Plate LXXIII, 4.) Third stage. — Length 0.82 mm., greatest width 0.44 mm. Antenna with four segments. Round-tipped spines arising from a base longer than the spines, and a few additional small spines on tubercles. Pro- and mesothorax beginning to increase in prominence. (Plate LXXIII, 5.) Fourth stage. — Length 1.2 mm., greatest width 0.7 mm. Wing pads of mesothorax extend- ing back over metathorax and first abdominal segment at sides. Prothorax more prominent than in earlier stages. Bases of round-tipped spines several times as long as the spines. A few new spines present on lateral margins of pro- and mesothorax and of abdomen. Color dark brown, except in an irregular band across abdomen just caudad of wing pads and on lateral thirds of prothorax, where it is yellowish. Minute spinules covering entire dorsum, light-colored on the yellowish parts and dark on the brown parts ; these spinules present also on bases of round-tipped spines. (Plate LXXIII, 6.) Fifth stage. — Length 1.6 mm., greatest width 0.96 mm. Wing pads now extending back to fourth abdominal segment at sides, and prothorax still more prominent. A few more spines on tubercles; many of the sharp-pointed spines of the earlier stages now round-tipped; spines present in the earlier stages on lateral margins of segments covered by wing pads have disappeared. Yellowish parts of prothorax increased in size, and distal part of wing pads yellowish, giving the body the appearance of having two light bands across it. Entire dorsal surface covered with minute spinules as in earlier stages. (Plate LXXIII, 7.) In all stages of the nymphs the larger spines correspond exactly in position and shape with those so excellently described by Morrill (1903) for the oak lace bug, Corythucha arcuata. The only distinguishing char- acters between the nymphs of the two species which the writer has been able to observe are the size and the prevalence of minute awl-shaped spinules on the dorsal surface. Nymphs of C. bellula are smaller, and possess more spinules, than those of C. arcuata. The larger spines of both species which- are mounted on elongate bases seem to have an eversible sac on the tip which gives them a trumpet shape when it is drawn in and a round tip when it is extended. The natural enemies of these spiny creatures seem to be few. Only the immature stages of several spiders were seen to prey upon them. The Insect Fauna of the Genus Crataegus 1061 The webs of these spiders sometimes cover the infested leaves of a tree and entangle whole colonies of the lace bugs. The adults that survive the winter are comparatively few, so that the first brood of C. bellula does little injury. Cicadellidae ( Jassidae) clitellarius Say, Thamnotettix The adults of Thamnotettix clitellarius are of medium size, 5 millimeters long. They are yellow, with black wings which have a prominent yellow spot. A few specimens were found on June 11. coccinea Forst., Graphocephala The adults of Graphocephala coccinea are 8 millimeters long, are slender, with a pointed head, and have the wings striped with alternate red and green. They are found on native hawthorns in July and August, but are not common. curtisii Fb., Euscelis The adults of Eased is curtisii are small, 4 millimeters long, with many narrow yellow and black stripes'. Specimens were found on June 23, but were not common. fitch i YanD., Icliocerus (Black apple leaf hopper) The adult of Idiocerus fitchi is 6 millimeters long, is brown or grayish with oblique white marks, and is found on native hawthorns in July and August. The black nymphs were reared on Crataegus punctata leaves from June 14 to July 2. The species winters in the egg stage. lachrymalis Fb., Icliocerus The adults of Icliocerus lachrymalis are 8 millimeters long, and are brownish or grayish mottled, with dark venation. They occur on native hawthorns in June and July. They are not common. lineatus Linn., Philaenus The adults of Philaenus lineatus are (i millimeters long, brownish yellow, stout with a pointed head, and with a small black spot near the apex on the inner margin of the wing. They are found on native hawthorns from July 1 to July 15, but are not common. mali LeB., Empoasca (Apple leaf hopper) The adults of Empoasca mali are 3| millimeters long, slender, pale green. They are found rarely on Crataegus in late June. obliqua Say, Erythroneura The adults of Erythroneura obliqua are 2| millimeters long, with the wings striped red and white. They are very abundant on the leaves of native 1()(>2 Walter H. Wellhouse hawthorns. They hibernate among the fallen leaves under the trees, and hundreds of them were present under Crataegus punctata trees in March, 1919. During warm days in winter they hop about over the leaves. Some individuals have pale pink stripes, and others reddish brown. Adults are found feeding on the trees in June and October. pallidus Fb., Idiocerus A single adult of Idiocerus pallidus was taken on June 23, on Crataegus punctata. It was 6 millimeters long, and was similar in size and shape to /. fitchi but was almost white. provancheri VanD., Idiocerus The adults of Idiocerus provancheri are 5| millimeters long, and are brown or blackish with an elongate yellow spot on the base of the inner margin of the wing. They are common on the leaves of native hawthorns during June and July. Nymphs in the rearing cages hatched from eggs in Crataegus punctata twigs just as the buds were expanding in April. They became adult in three weeks. querci Fitch, Empoa The small, whitish leaf hoppers known as Empoa querci are very abundant on both native and imported hawthorns. The nymphs may be found on the under side of the leaves in late June and July, and again in September. The adults likewise occur on the under side of the foliage in June, August, and late September or early October. They hibernate among the fallen leaves and become active on warm winter days. They are 3 millimeters long, and are pale yellowish white in color. seminudus Say, Eutettix The adults of Eutettix seminudus are 4| millimeters long, rather stout, and white with a light brown band across the middle of the wings. They are rather common on Crataegus punctata and C. tomentosa foliage from mid-July to September. suturalis Fb., Idiocerus The adults of Idiocerus suturalis are 5| millimeters long, and are pallid except for the black inner margin of the wings. They are found on native Crataegus in June and July, but are rare. vanduzei Gill., Eupteryx The adults of Eupteryx vanduzei are 2| millimeters long, and are slender with a pointed head. The head, the thorax, and the apical part of the wings are brown, and the central part of the body and of the wings is greenish yellow. One nymph was taken on Crataegus punctata foliage, and the adult emerged on August 15. The species is rarely found. The Insect Fauna of the Genus Crataegus 1063 vulgaris Fb., Lamenia The adults of Lamenia vulgaris are 4 millimeters long, bluish gray, and rather stout. They are abundant on native hawthorns during the last half of June. Membracidae crataegi Fitch, Glossonotus (Hawthorn tree hopper) The adults of Glossonotus crataegi are fairly common on the branches of native hawthorns during July and early August . flavicephala Coding, Ophiderma The adults of Ophiderma flavicephala are 8 millimeters long, are brown with a yellowish white stripe on each side and across the rear end of the prothorax, and are without a hump. They are rarely found on the branches of Crataegus punctata and C. tomentosa during June. taurina Fitch, Ceresa The adults of Ceresa taurina are 8 millimeters long, are pale green, and have the prothorax prolonged into a horn on each side of the head. They are found occasionally on the branches of Crataegus punctata and C. neofluvialis in late July and August. No nymphs were reared to the adult stage on Crataegus, but several nymphs answering the description of this species as given by Hodgkiss (1910) hatched on April 20 and lived through three in- stars on Crataegus punctata, foliage. Aphididae corrugatans Sir., Pemphigus (Woolly thorn aphis) A few colonics of the flocculent greenish aphids of the species Pem- phigus corrugatans were found in early June on Crataegus punctata. They live on the under side of the leaves and curl the leaf margins downward. crataegi Monell, Macrosiphum The apterous females of Macrosi- phum crataegi may be found from late May until October on the native haw- thorns at Ithaca, and during July and August the species may become so abundant as to seriously injure the Fig. 108. macrosiphum grataeci 1064 Walter H. Wellhouse trees. During the summer of 1919 the writer saw a small Crataegus prui- nosa tree killed and a very large C. 'punctata tree almost entirely defo- liated due to the sucking of sap by myriads of these aphids. They are rather large, yellowish green aphids, with long cornicles, and their most easily recognizable character is the presence of four dark green spots arranged in a rectangle on the dorsal side of the abdomen (fig. 108). The entire life history is passed on Crataegus trees. The black winter eggs are placed on the twigs and the smaller branches. They begin to hatch in May, after the leaves are well opened. The young aphids move to the lower surface of the leaves, and their feeding, as the colony increases, causes the leaves to curl downward. In late June an alate brood appears and migrates to near-by branches or trees to start new colonies. It is after this brood appears that the species becomes so injurious. crataegifoliae Fitch, Aphis In early May, 1918, the Crataegus coccinea trees at Ithaca began to show the terminal rosettes of curled leaves caused by Aphis crataegifoliae. The rosettes turned red, and the aphids within them also were red. The infested branches remained de- formed and somewhat stunted throughout the season, although the aphids departed from the trees about May 20 to seek leguminous hosts. No aphids of this species were observed the next year. lanigera Hausm., Erio- soma (Woolly aphis) The woolly aphids first become noticeable in early June as small white spots on the tender twigs of Crataegus. In a favor- able season such as the summer of 1918, they be- come very conspicuous and cover entire branches by late summer (fig. 109). The writer has not found the roots of Crataegus Fig. 109. f.riosoma lanigera on hawthorn infested. The Insect Fauna of the Genus Crataegus 1085 pomi De Geer, Aphis (Green apple aphis) During June and July the succulent sprouts of European and native hawthorns are badly infested by green apple aphids. Whenever the weather becomes unfavorable for their enemies they increase rapidly and infest entire trees or hedges, but fair weather checks them again. prunifoliae Fitch, Rhopalosiphum (Apple bud aphis) The dark green stem mothers of the species Rhopalosiphum prunifoliae begin to appear on the buds of native hawthorns as soon as the bud scales have separated enough to show the green leaves within. The colonies increase during April and early May, doing some damage to the young leaves and buds, but before June they migrate from the trees to grasses and are not often found on the trees between early June and late autumn. The winter eggs are laid on hawthorn twigs and buds. Coccidae corni Bouche, Lecanium (European fruit lecanium) The species Lecanium corni is often very abundant on the lower side of branches of native hawthorns, and occasionally a branch is found to be almost entirely covered with these scales. Lower or inner branches that receive a scanty supply of light appear to be killed by them. The young, flat scales are sometimes very plentiful on the leaves in late summer. furfura Fitch, Chionaspis (Scurfy scale) The flat, whitish scale known as Chionaspis furfura is very common and noticeable on the bark of all Crataegus species which the writer has observed. The small, elongate, white, male scales are often very abundant on the leaves and bark of Crataegus punctata. The injury caused by these scales is not noticeable. perniciosus Comst., Aspidiotus (San Jose scale) Although the San Jose scale is fairly common on all species at Ithaca, it does not seem to increase rapidly enough to become injurious. It is more commonly found on the smooth bark of young trees than on old, rough-barked trees. ulmi Linn., Lepidosaphes (Oyster-shell scale) The oyster-shell scale is common on the bark of native and European hawthorns, and a few badly infested branches have been found. Gen- erally, however, this species seems to be unimportant as a pest of Crataegus. vitis Linn., Pulvinaria (Cottony scale) The species Pulvinaria vitis is occasionally found on the twigs and branches of native hawthorns, but is not very abundant. 1066 Walter H. Wellhouse Thysanoptera Thrvpidae tritici Fitch, Euthrips Nymphs and adults of Euthrips tritici are very common in flowers and flower buds of native hawthorns in April and May. Many flower buds fail to open, and inside of them are found from one to a dozen or more of these thrips. They were exceedingly abundant in the Cornell University arboretum in 1918, and very few hawthorns there bore fruit that year. COLEOPTERA Elateridae dubitans Lee, Limonius The beetles of the species Limonius diibitans occasionally are found eating leaves of native hawthorns in late May and early June. On May 31, 1919, one of these click beetles was found on a Crataegus pruinosa leaf where it had been feeding, and was attacked by an adult pentatomid, Apeteticus modestus Dallas. The latter had its beak inserted into the beetle, which died while being carried to the laboratory. pubescefis Melsh., Agriotes The beetles of Agriotes pubescens were eating the leaves of Crataegus punctata on May 23. The species is not common. Mela not us sp. The beetles of Melanotus sp. were eating the leaves of Crataegus punctata on June 6 and June 8. The species is not common. Buprestidae aerosus Melsh., Brachys The beetles of Brachys aerosus were found feeding on Crataegus punctata leaves in warm sunlight from May 30 to June 20. There were commonly two or three to a leaf, feeding on the upper surface and cutting small holes through the leaf. As many as fift} r of the beetles were found on one tree, while neighboring trees had none. They are from 4 to 5 millimeters long, and are brown and gold in color. Scarabaeidae elongata Fabr., Dichelonycha The beetles of Dichelonycha elongata were found feeding on Crataegus punctata foliage, six being seen on One tree on May 31. A seventh beetle was killed by three adult pentatomids of the species Apeteticus modestus, which were feeding on its body. The Insect Fauna of the Genus Crataegus 10G7 testacea Kirby, Dichelonycha The beetles of Dichelonycha testacea were found on Crataegus tomentosa foliage on May 29 and July 1. They cut irregular patches from the edge of the leaf. The species is not common. Chrysomelidae borealis Shev., Dibolia The green flea beetles of the species Dibolia borealis are 2\ millimeters long. They feed on native hawthorn foliage in May, as soon as it is expanded. They hibernate beneath bark scales on the trunk and the branches, and when warmed in the hand in February they very soon become active. carinata Germ., Haltica The metallic violet or green flea beetles of the species Haltica carinata are 4 millimeters long. They feed on foliage of native hawthorns in June. They are not common. cucumeris Harris, Epitrix Tiny shining bluish beetles less than 2 millimeters long, of the species Epitrix cucumeris, were found feeding on Crataegus punctata foliage in June. The species is not common. helxines Linn., Crepidodera The shining greenish flea beetles of the species Crepidodera helxines are 3 millimeters long. They feed on the foliage of native hawthorns and are frequently so numerous as to cause considerable injury. They are found feeding in May, June, July, and August, but are most abundant in late May and in June. The beetles hibernate under bark scales on the trunk and the larger branches, where many of them die from the attack of a white fungous growth before spring. marginalis 111., Systena Yellowish brown, slender flea beetles 4 millimeters long, of the species Systena marginalis, were found in August and early September eating holes in leaves of native hawthorns. The species is fairly common. villosula Melsh., Xanthoma The stout brownish or black beetles of the species Xanthoma villosula are 4 millimeters long. They were found feeding on the leaves of Crataegus punctata from late June to early August. Occasionally they are so abundant as to completely riddle the foliage of a tree with the holes they cut in feeding (Wellhouse, 1919). Feeding punctures are shown in figure 110, on the following page. 1068 Walter H. WellhoDse Curculionidae crataegi Walsh, Conotra- chelus (Quince cur- culio) The square-shouldered brown beetles of Cono- trachelus era taegi were found puncturing the fruit of Crataegus for feeding and oviposition in July and August, 1918, and in late May and June, 1919. The early months of 1919 were much warmer than those of 1918 at Ithaca, and this probably is the cause of the great variation in the time of their appearance. The larvae develop within the haws, feeding on the pulp surrounding the large, stony seeds. A larva commonly eats about one-half of the en- tire pulp of the fruit before emerging in the autumn, when it leaves the fruit by a large, round, exit hole. It then burrows down two or three inches in the soil and spends the winter as a larva curled in a smooth- walled earthen cell. In June, 1918, the writer found ninety-six larvae in the soil beneath one Crataegus punctata tree. Some of them pupated in June and others in July. They are very common on all the native hawthorns. nebulosus Lee, Anthonomus (Hawthorn blossom weevil) One of the most interesting and injurious of the insects found on the hawthorns is Anthonomus nebulosus, a member of a very destructive genus of blossom weevils. Its mode of life resembles in a general way that of the Mexican cotton boll weevil, A. grandis, and is almost identical with that of the European apple-blossom weevil, A. pomorum (Theobald, 1909: 104-110). The original description of A . nebulosus is to be found in the Proceedings of the American Philosophical Society (Leconte, 1876), and a more com- plete description is given by Dietz (1891). In the present account it is FlG. 110. FEEDING PUNCTURES OF XANTHONIA VILLOSULA IN LEAVES OF CRATAEGUS PUNCTATA The Insect Fauna of the Genus Crataegus 1069 sufficient to say that A. nebulosus is a brown or grayish oval beetle, from 3.75 to 4.25 millimeters long, generally with a whitish, V-shaped mark on the fore part of the elytra, with a long, slender, curved beak, and the front femur having two teeth on its apical part, one large and the other small (Plate LXXIV, page 1070). The species has been found in New York, New Jersey, Michigan, Indiana, Missouri, Arkansas, and Louisiana, and therefore it seems probable that it is present wherever its hosts are found east of the Rocky Mountains. Although Dietz considers this species to be more charac- teristic of the European fauna than of our own, no record can be found of its occurrence in Europe or elsewhere outside of this country. Its hosts include a number of the larger-flowered species of hawthorns, such as Crataegus punctata, C. brainerdi, C. pruinosa, and C. mollis. The smaller-flowered species, such as C. oxyacantha, are not selected by the beetles for oviposition, probably because there is not space enough for the full development of the larva within the bud. The injury caused by the hawthorn blossom weevil is most apparent while the trees are in full bloom. At that time the infested blossoms are brown and remain closed. On badly infested trees fully fifty per cent of the blossoms may be in this condition and the trees present a scorched appearance. As the young fruit begins to set, the infested blossoms com- monly fall to the ground, but they may sometimes be seen on the trees even after the beetles have emerged in June. The beetles come out of hibernation and appear on the branches of the hosts about mid- April, feeding ravenously on the buds, which are showing green. It is not uncommon to see a beetle with feet braced and beak inserted up to the eyes in a bud while it hurriedly eats the tender leaves within. As soon as all the food within reach of the entrance hole is eaten, the beetle seeks another bud on the twig and repeats the process. The puncture in the bud is round, is 0.3 millimeter in diameter, and turns dark as soon as the beak is withdrawn. The presence of the beetles may be detected by these dark round holes in the buds before the egg-laying period arrives. The beetles continue to feed on the buds during suitable weather until the clusters have separated enough for oviposition in the blossoms. During cool weather the beetles remain inactive, generally in the axils of the twigs with their heads down. A few observations on the relation of temperature to their activities were made, and these indicate that the beetles remain inactive while the temperature is below 50° F. The optimum temperature is from 60° to 70°, and when it is raised to 78° the beetles rush about like mad, attempting to oviposit in every bud. Under most conditions they seem reluctant to fly, but when placed on distasteful food they fly away. They continue their activities on cloudy or rainy days and at night if the temperature is sufficiently high. Memoir 56 Plate LXXIV ANTHONOMUS NEBULOSUS 1, Feeding punctures of beetles in hawthorn fruit. 2, Egg in blossom[pud. 3,f Female ovipositing in blossom bud. 4, Flower with petals removed to show full-grown larva in its natural position. 5, Adult beetle. 6, Three flower buds containing larvae, and one normal blossom. 7, Flower with petals removed to show pupa in its natural position 1070 The Insect Fauna of the Genus Crataegus 1071 The period between the opening of the blossom clusters and the opening of the blossoms themselves is the time of oviposition, and the length of this period probably influences the amount of injury to a considerable extent. If it is prolonged by cool, cloudy weather, then eggs may be placed in more of the blossoms before they open. In central New York the oviposition period is about May 15. After selecting a suitable blossom bud, the female makes a hole in the side of the calyx with her beak. Then, turning around, she thrusts the egg into the hole with her ovipositor, and moves to another bud to repeat the process. A clear liquid fills the hole where the egg is thrust in, which soon hardens and seals the opening completely. The act of oviposition requires about ten minutes when the temperature is 68° or 70°, but it requires an hour at 54°. The egg is pearly white, 0.6 millimeter long, 0.36 millimeter wide, elliptical, generally the same size at both ends but when tucked in tightly between the anthers it may be narrower at one end to conform to the space it fills. It is of almost the same size and color as the anthers and is difficult to distinguish from them. The corium is smooth, unsculp- tured, and delicate, drying and collapsing when exposed to the air for one hour. After about a week the young, white, curved, legless larva is found within the bud. It feeds on the anthers, and, as it grows, consumes all the internal parts of the flower but leaves intact the wall of the receptacle and the closed petals which form the roof of its house. The petals become stiff as if they were starched, and do not shrink away as they turn brown. After feeding for a couple of weeks the larva is dirty white, is from 6 to 8 millimeters long, is still legless, has a small brown head, and lies in a curved position. At about this time it molts and changes to a white, free pupa 6 millimeters long, with a dark caudal spine, two dark promi- nent spines on the apex of the head, and several smaller spines farther back on the head. After pupating during a week or a little longer, the beetle makes a hole in the top or the side of its house with its beak, and emerges. It begins to feed a few minutes after emergence, choosing for its food the first young thorn or fruit in its pathway as it wanders along the branch. The thorns of the current season's growth seem to be a very attractive food. A hole is drilled near the base of the thorn, and the beetle spends hours with its beak inserted in the hole completely up to its eyes, prying and straining to enlarge the cavity within the thorn. The round hole at the base of a thorn does not heal during the season's growth, and the presence of such holes will indicate at any time of the year the presence of the blossom weevils. The beetles attack the fruit also and make several round holes in a single fruit before seeking another. The holes become brown almost immediately. The writer has never found 1072 Walter H. Wellhouse the beetles eating leaves or tender twigs, but they sometimes feed on the succulent globular leaf galls of cecidomyiid larvae. They will puncture and feed on young apples in the cages when fresh haws are not to be had, but the writer has found none feeding on apples in the field. After feeding for a week or ten days the beetles may be found in copula- tion on the branches, and a week or so later, as warm July weather comes, they disappear from the trees. Those kept in breeding cages remained hidden in fallen curled leaves and hollow twigs on the ground all summer and winter without feeding until the next spring. A search for their hiding places in the field revealed a score of the beetles inclosed in curled, dried leaves on the ground beneath their host trees. The life cycle may be summarized as follows: The immature stages (egg, larva, and pupa) are completed within the closed blossom in from twenty-seven to thirty-five days, and the remainder of the year is passed in the adult stage. The adults feed on thorns and fruit for two or three weeks after emerging from the blossoms, and then remain quiescent among fallen leaves on the ground until the next spring, when they feed for about a month on the buds before ovipositing. Soon after oviposition the beetles die. In New York the eggs are laid about mid-May and the beetles emerge from the blossoms in June. W. D. Pierce, in a letter to the writer, says the beetles emerge in late March and early April in Lou- isiana. The time of their development in different latitudes is dependent on the opening of the hawthorn blossoms in those latitudes. A number of natural enemies of the blossom weevil have been observed. Various birds, especially sparrows, pick open the brown blossoms to eat the larvae and the pupae. Pierce (1912:77) found the weevils to be para- sitized by Catolaccus hunteri and Sigalphus sp. The writer has bred another chalcid, Habrocytus piercei Cwfd., from the larva of the weevil, the adult parasites emerging on June 16 and 17. quadrigibbus Say, Tachypterus (Apple curculio) The four-humped brownish beetles of the species Tachypterus quadri- gibbus were found occasionally feeding on the fruit of native hawthorns in June. Fruits of Crataegus punctata were put into rearing cages on June 25, and from these fruits five adults of this species emerged on July 15 and July 18. Lepidoptera Papilionidae turnus Linn., Papilio (Tiger swallowtail) The green larvae of Papilio turnus, with their peculiar eye spots, were found feeding on the foliage of native hawthorns from June 20 to August 2. The species is not very common. The Insect Fauna of the Genus Crataegus 1073 Saturniidae io Fabr., Automeris The eggs of Automeris io are not uncommon on the under side of haw- thorn leaves in late June and in July. They are very characteristic and conspicuous. A cluster of eggs may consist of a dozen or more, each large and creamy white with a dark blue dot on the distal end. The larvae feed in colonies on the foliage during July, August, and September. They are at first dark, then green, and are always covered with a mass of dark, stinging spines. Arctiidae caryae Harris, Halisidota (Hickory tussock moth) The black-and-white-tufted caterpillars of the species Halisidota caryae are fairly common on native hawthorns during August. tesselaris A. and S., Halisidota The caterpillars of Halisidota tesselaris are similar to those of H. caryae and are found occasionally on the foliage with them, but are not so common. textor Harris, Hyphantria (Fall webworm) A single colony of larvae of Hyphantria textor was feeding on Crataegus pruinosa on July 31, 1918. An egg cluster which was probably of this species hatched on June 19, and the young larvae fed on C. punctata leaves for a few days and then died. Noctuidae americana Harris, Acronycta The larvae of Acronycta americana are green, with an abundant covering of yellowish white hairs and a few long pencils of black hairs. They were found feeding on the leaves of native hawthorns in late June and July. The species is not common. dactylina Grote, Acronycta The larvae of Acronycta dactylina are entirely covered with yellowish white hairs and have three long pencils of black hairs. They were feeding on the foliage of Crataegus punctata from August 15 to September. The species is not common. luteicoma G. and R., Acronycta The larvae of Acronycta luteicoma are black, with tufts of white hairs on segments 3 to 6 and tufts of black hairs on the other segments. They were found feeding on Crataegus punctata leaves from June 23 to July 22. The species is not common. 1074 Walter H. Wellhouse occidentalis G. and R., Acronycta The larva of Acronycta occidentalis is hairy, with a dark head and dorsal stripes. The remainder of the body is at first whitish but in later stages is reddish. Larvae of this species were feeding on Crataegus punctata foliage from August 13 to September. The species is not common. pyramidoides Guen., Amphipyra The larva of Amphipyra pyramidoides is green, with a white dorsal and two yellow lateral stripes, and is found feeding on native hawthorn leaves in May. One larva constructed a silken cocoon among dead leaves on the ground on June 2 and the moth emerged on July 18. The species is not common. radclijrfei Harv., Acronycta The larva of Acronycta radcliffei is greenish or black, has a dorsal line of green or brown with faint yellow and red lines, has a hump on segment 12, and is sparsely hairy. It feeds on the leaves of Crataegus punctata from June 29 to July 22. The species is not common. superans Guen., Acronycta The larva of Acronycta superans is green, with a black dorsal line widened into a spot on several abdominal segments and with the last segment angularly elevated. There are few hairs on the body. It was feeding on Crataegus punctata leaves from June 9 to July 1, and pupated in a silken cocoon among leaves and decayed wood on the ground. The moth emerged on July 23. Only one larva was found. Notodontidae concinna A. and S., Schizura (Red-humped apple caterpillar) The brownish, red-humped larvae of Schizura concinna feed on leaves of native hawthorns during July, August, and early September. Occa- sionally they defoliate several branches of a tree, but they are not generally injurious as is Datana ministra. They seem to prefer apple to hawthorn. On July 27, 1918, a count was made of the infested trees in several thickets where seedling apples and hawthorns were growing together. Although the hawthorns were much more numerous than the apples, the latter had forty-six infested trees while the former had only three. manteo Doub., Heterocampa The larva of Heterocampa manteo is bright green marked with red. It was found feeding on the foliage of native hawthorns in late June and in July. The species is not very common. One larva taken from a Crataegus punctata tree on August 15 continued to feed in the cage until September 2, when it wandered away to find a suitable place for spinning its cocoon. The Insect Fauna of the Genus Crataegus 1075 ministra Dru., Datana (Yellow-necked apple caterpillar) One of the most destructive species to both native and European haw- thorns during the past few years has been Datana ministra. Very few trees have escaped without at least one colony of these yellow-necked, black-bodied, gray-haired caterpillars feeding on a branch in July and August. Many trees have had an entire branch stripped bare of leaves, and occasionally a whole tree has been defoliated. The light brown moths appeared and were found ovipositing during June and July. The clusters of white eggs, each cluster containing from 25 to 100, were deposited on the lower side of the leaves and were a common sight in July. The larvae of a colony begin to feed at the tip of a branch and migrate toward its base as they grow, leaving the bare branch behind them. As they become larger they scatter to adjacent branches and feed singly or by twos and threes. They become full-grown and enter the soil in September. Several observations were made to determine whether the larvae pre- fer hawthorn to apple. When confined in cages they eat one as readily as the other. In the natural uncultivated areas where hawthorn, apple, and pear grow wild, however, it was noticed that the colonies of larvae were commoner on hawthorn than on the other trees. In one field con- taining 50 hawthorn, 39 apple, and 17 pear trees, 79 colonies of larvae were counted. Of these colonies 56 were on hawthorn, 15 on apple, and 8 on pear. Lymantriidae leucostigma A. and S., Hemerocampa (White-marked tussock caterpillar) The larva of Hemerocampa leucostigma, with its bright red head, its red tubercles on segments 6 and 7 of the abdomen, its four white tussocks, and its three long, black pencils of hairs, is a common sight on both native and European hawthorns. It feeds on the foliage during June and July, and the hairy cocoons are common on the branches in winter. Lasiocampidae americana Harris, Epicnaptera The large larva of Epicnaptera americana is gray with white spots and two red bands above, and orange with a row of lateral diamond-shaped black spots below. It feeds at night on Crataegus punctata foliage in July and August. The species is not common. americana Fabr., Malacosoma (Apple tent caterpillar) During the years 1917 to 1920, only the old egg masses of Malacosoma americana were found on the twigs of hawthorns about Ithaca. Only two colonies of larvae were seen on the favorite host, wild cherry, and only one colony on apple. 1076 Walter H. Wellhouse Qeometridae cognataria Guen., Lycia The larva of Lycia cognataria is green and is 4| centimsters long. It has two pairs of prolegs. On its head are blunt horns, and it bears a prominent red tubercle on the next to the last segment. It feeds on Crataegus punctata and C. pruinosa foliage in July. It is not a common species. magnarius G uen . , Ennomos A moth of Ennomos magnarius emerged from a brown silken cocoon on a twig of Crataegus pruinosa on September 30. Eggs were found on a C. punctata twig on November 12. The brownish larvae, 5 centimeters long, were found occasionally in May and June. pometeria Peck, Alsophila (Fall canker worm) The small greenish or brownish larvae of Alsophila pometeria are fairly common on native hawthorns in May. subsignarius Hub., Ennomos The white moths of Ennomos subsignarius emerged on July 6 and July 18 from pale yellowish pupae which were found tied with silk between the leaves of Crataegus punctata. A few of the brown and red larvae were found feeding on the foliage of native hawthorns in May. tiliaria Harris, Erranis (Lime-tree spanworm) The yellow-and-black-striped larvae of Erranis tiliaria are common on native hawthorn foliage in May and June. titea Cram., Phigalia Two larvae of Phigalia titea were found feeding on Crataegus punctata leaves on June 2 and June 5. vernata Peck, Paleacrita (Spring cankerworm) The larvae of Paleacrita vernata are common on foliage of native and European hawthorns in May and early June. Sesiidae (Aegeriidae) scitula Harris, Sesia A single Crataegus punctata tree about eight years old and 5 feet high was killed by the larvae of Sesia scitula. The 'trunk was entirely girdled by four larvae which tunneled beneath the bark two inches above the soil. The sapwood was only slightly indented by their burrows around it. They pupated during June in silken cocoons covered with frass within the burrows, and the moths emerged from July 18 to July 24, In emerg- The Insect Fauna of the Genus Crataegus 1077 ing, the moth pushes through one end of the cocoon, and then sheds the pupal skin while protruding about two-thirds of its length beyond the cocoon. The black, clear-winged moth has a broad and a narrow band of yellow across the abdomen. Pyralidae indigenella Zell., Mineola (Leaf crumpler) The cornucopia-like winter cases of Mineola indigenella, a leaf crumpler, are easily seen on almost any hawthorn tree during the winter, attached firmly to the twigs and the branches and often with partly eaten leaves attached. The larvae carry the cases with them and feed on the leaves in April and May. They pupate within the same cases attached to twigs in June, and at Ithaca the moths emerge in late June. Tortricidae argyrospila Walk., Archips (Fruit-tree leaf roller) The greenish larvae of Archips argyrospila, with their black heads and shields, are fairly abundant on the foliage of native hawthorns during May and are found occasionally in June. They tie together a cluster of leaves and feed on a leaf within the cluster. Moths emerged from the larval nests in late June and early July. chionosema Zell., Oleihreutes The pale green larvae of Oleihreutes chionosema fold the leaves of native hawthorns and feed on the upper surface of the leaves within the fold. Each larva folds a single leaf at a time. They are fairly common on the hawthorns and apple trees about Ithaca during May. The moths fly during June after pupating within the folded leaf. A few moths taken on August 14 and 15 seem to indicate a second brood. The moth (fig. Ill) is brownish, with a large white spot on the costal edge of the fore wing, and has a wing expanse of from 15 to 16 millimeters. Fig. 111. olethreutes chionosema nubeculana Clem., Ancylis The greenish larvae of Ancylis nubeculana were found in late summer in rolled leaves of Crataegus punctata. They pupated in May and the moths emerged from June 8 to June 18. The species is not very common. 1078 Walter H. Wellhouse ocellana Fabr., Tmetocera (Bud moth) The brownish larvae of Tmetocera ocellana are commonly found in the partly opened leaf buds in April and May, on both native and European hawthorns. The moths emerge from the larval nests in June and early July. prunivora Walsh, Laspeyresia (Lesser apple worm) The small white caterpillars of Laspeyresia prunivora are very common in the fruit of many native hawthorns in late summer. They eat most of the pulp from one side of the fruit, causing the skin to sink in there. The larvae of the second generation sometimes remain in the fruit all winter, living within a mixture of silk and pellets of frass. Others spin silken hibernacula under the bark of the trunk very similar to those of the codling- moth larvae but smaller. They pupate within the hibernacula in the spring and the moths emerge in May and June. In the laboratory they emerged in March. Moths of the first generation were taken in the field from August 15 to August 30. quadrifasciana Fern , Eulia The yellowish larvae of Eulia quadrifasciana tie together with silk the leaves of terminal clusters on Crataegus punctata in May. They pupate within the larval nests and the moths emerge in early June. The moth is yellow and orange, with darker oblique bands on the fore wings. The species is not very common. rosaceana Harris, Cacoecia (Oblique-banded leaf roller) Clusters of leaves tied together by the larvae of Cacoecia rosaceana are fairly common on all native hawthorns in May and July. The green- striped larva, with its brown head and shield, is generally found on a single leaf under a slight web, feeding on one side of the leaf only. When full- grown the larva ties a cluster of leaves together to pupate within. Moths emerged from these nests from May 26 to June 30, and a second brood emerged from August 1 to August 15. Yponomeutidae oreasella Clem., Argyresthia The small, green, black-headed larva of Argyresthia oreasella bores through a terminal leaf bud down into the twig and makes a hole in the side of the twig about h inch from the tip, through which the frass is cast out of the burrow. When disturbed the larva runs quickly out of either the hole in the twig or the hole in the bud, to escape. Infested twigs wilt soon after the larva has left the burrow, and then become brown and dry, giving the tree a fire-blighted appearance (fig. 112). Larvae of this species were found in many native hawthorn twigs in May. They leave the The Insect Fauna of the Genus Crataegus 1079 twigs when full-grown, and spin a parchment-like white cocoon surrounded by an open layer of lacework attached to the surface of a leaf. The moths emerged from June 15 to June 30. A few moths taken in the field on August 16 seem to indicate a second brood. The moth is slender, and is white with ob- lique gold bands on the fore wings while the hind wings are dark gray. Its wing ex- panse is about 13 millimeters. It has a peculiar habit of ^ f / standing on its head when at rest on the leaves or the bark. Elachistidae fletcherella Fern., Coleophora (Cigar case-bearer) The brown, cigar-shaped cases of the larvae of Coleo- phora fletcherella are common on all the hawthorns through- FlG m TERMINAL OF hawthorn twig destroyed out the growing season. They B y larva of argyresthia oreasella have been specially abundant and injurious on trees and hedges of Crataegus oxyacantha, the European hawthorn, during the years 1918 and 1919. The moths emerged from the cases in late June and July. malivorella Riley, Coleophora (Pistol case-bearer) The curved cases of the larvae of Coleophora malivorella are fairly common on hawthorns but not so abundant as those of C. fletcherella. splendoriferella Clem., Coptodisca (Resplendent shield-bearer) The small, yellowish brown, winter shields of Coptodisca splendoriferella are rather commonly found attached to the bark and swinging in the wind on the branches of native hawthorns, and their blotch mines in the leaves are not uncommon. Lyonetiidae . pomifolieUa Clem., Bucculatrix (Ribbed-cocoon-maker of apple) The elongate,' white, ribbed cocoons of Bucculatrix pomifolieUa are common on native hawthorns and are rather noticeable in winter, when the trees are leafless. The moths emerge in late May. 1080 Walter H. Wellhouse Cosmopterygidae curvilineella Chamb., Blastodacna (Hawthorn fruit miner) The larvae of Blastodacna curvilineella are very commonly found tunneling in the fruit of native hawthorns in late summer. They become full-grown in September and October, when they leave the fruit and burrow into the ends of dead twigs or other decaying wood to hibernate. The hibernation cavity is lined with silk, and in the early spring pupation takes place there. The moths emerge in May and June. They are gray, with two or three indistinct dusky longitudinal short streaks on the wings, and have a wing expanse of 1 centimeter. The larva is from 9 to 10 millimeters long. In color it is yellowish white, with a brown head and thoracic legs, red spots near the spiracles, more or less blackish among the setae on the dorsum of each segment but especially noticeable on the prothorax and the anal segment, and many patches of black setae arranged as shown in figure 113. It feeds on the pulp of the fruit and leaves many brown pellets of excrement in the bur- row behind it. Often one whole side Fig. 113. larva of blastodacna r r •, • - i n , i „ • „ __i„. curvilineella of a f rmt 1S mined out, leaving only the skin to cover it. The moths have been bred from larvae in Crataegus pruinosa, C. neo- fluvialis, and C. macracantha, and the larvae have been found in a number of other native hawthorns. The moth has been reported by Chambers from Kentucky (1872) and from Canada (1875), and therefore it probably occurs throughout the Eastern States. A closely related European species, B. hellerella Dup., feeds in the fruit of hawthorns and also bores into young apple shoots (page 1116). DlPTERA Cecidomyiidae (Itonididae) absobrina Felt, Rhizomyia crataegifolia Felt, Lestodiplosis (Hawthorn f ringed-cup gall) Adults of both Rhizomyia absobrina and Lestodiplosis crataegifolia have been reared by Dr. Felt from larvae in the galls. The galls are green and cup-shaped, and are covered externally with round-tipped spines 4 or 5 millimeters in diameter and about the same in height (figs. 114 and 115). They occur on the larger veins and petioles of leaves and on the ends of young twigs of Crataegus pruinosa and C. macracantha. Several galls are commonly found in a group on the same or adjoining leaves. Those on the leaves are on the upper side, but extend through the leaves to form a smooth, semi-globular swelling on the lower side. The Insect Fauna of the Genus Crataegus 1081 Fig. 114. hawthorn fringed-cup galls Fig. 115. cross section through a hawthorn fringed-cup gall 1082 Walter H. Wellhouse White larvae, 3.5 millimeters long and with a distinct brown breast-bone, were found, one in each gall, in June. crataegifolia Felt , H ormomyia (Thorn cockscomb gall) Green or red cockscomb-like galls (figs. 116 and 117) produced by Hormomyia crataegifolia are found on the upper or the lower side of leaves of Crataegus pru- inosa, C. macrosperma, and C. coccinea. They are often in groups on a leaf or a cluster of leaves, and each gall includes a vein. The gall is from 8 to 12 millimeters long and 5 millimeters high, and is open to the outside by a long, narrow slit on the opposite side of the leaf. These galls are found in August. venae Felt, Lobopteromyia (Thorn Fig. 116. thorn cockscomb gall vein gall) Round or oval, thick-walled, green galls (figs. 118 and 119) from 5 to 8 millimeters long, produced by Lobopteromyia venae, are found on either the upper or the lower surface of leaves of Crataegus punctata. The gall opens on the opposite side of the leaf by a narrow slit which extends the entire length of the gall in the direction of. the vein. It always includes one of the larger veins. The galls are fairly abundant in June, when several may be found on one leaf and all the leaves in a cluster are deformed. Cecidomyia sp. (a. 1840 Felt) (Thorn spindle gall) Red or green, elongate spindle-shaped galls (figs. 120 and 121) 2 millimeters wide and from 5 to 10 millimeters long, produced by Cecidomyia . sp., are found on either side SSSSSSSSS^ 1 . 1917. bedeguar Walsh, Cecidomyia (Tufted thorn gall) Fam. Cecidomyiidae Host — Crataegus. Injury — Larvae deform leaves with filamentous subglobular vein galls, 1 cm. long, generally found on the midveins. Distribution — North America. References — Walsh, B. D. Can. ent, 1 : 79. 1869. Felt, E. P. New York State Mus. Bui. 200: 138. 1918. a ra si 'folia Felt, Mycodiplosis Fam. Cecidomyiidat Hosts — Prunus virginiana, Crataegus. Injury — Larvae live in galls on hawthorn fruit caused by Gymnosporangitun clavipes, and feed on the rust spores. Distribution — North America. References — Felt, E. P. New York State Mus. Bui. 200: 152. 1918. Wellhouse, W. H. Ent. news 30: 144. 1919. circumdata Winn., Perrisia Fam. Cecidomyiidae Host — Crataegus oxyacantha. Injury — Larva lives in leaf gall. Distribution — Germany. References — Kaltenbach, J. H. Pflanzenfeinde. p. 212. 1872. Kieffer, J. J. Genera insectorum, fasc. 152, p. 75. 1913. crataegi Winn., Perrisia Fam. Cecidomyiidae Host — Crataegus oxyacantha. Injury — Colonies of larvae cause rosettes of deformed sessile leaves, which make trees and hedges unsightly. Distribution — Europe. References — Kaltenbach, J. H. Pflanzenfeinde. p. 212. 1872. Connold, E. T. British vegetable galls, p. 190. 1902. crataegifolia Felt, Hormomyia (Thorn cockscomb gall) Fam. Cecidomyiidae Host — Crataegus. Injury — Larva deforms leaf with a green or red gall 1 cm. long, shaped like a cockscomb. Distribution — United States. References — Felt, E. P. Journ. econ. ent, 1 : 20. 1908. Felt, E. P. New York State Mus. Bui. 200: 136. 1918. (Figs. 116 and 117, pa ? e 1052.) 1130 DlPTERA crataegifolia Felt, Lestodiplosis (Hawthorn fringed-cup gall) Fam. Cecidomyiidae Host — Crataegus. Injury — Larva causes a gall on leaf or twig. Distribution — United States. References — Felt, E. P. New York State Mus. Bui. 124:408. 1908. Felt, E. P. New York State Mus. Bui. 200:138. 1918. (Figs. 114 and 115, page 1081.) excavata Felt, Lasioptera (Purple leaf blotch) Fam. Cecidomyiidae Host — Crataegus. Injury — Larvae deform leaves with green or reddish, blister-like mines, about 8 mm. in diameter. Distribution — United States. Reference — Felt, E. P. New York State Mus. Bui. 200:138. 1918. hirta Felt, Rhizomyia Fam. Cecidomyiidae Host — Crataegus. Injury — ■ Species probably inquiline in blister mine made by Lasioptera excavata. Distribution — United States. Reference — Felt, E. P. New York State Mus. Bui. 200: 138. 1918. hudsonici Felt, Winnertzii Fam. Cecidomyiidae Host — Crataegus. Injury — Larva deforms leaf with stout, cup-shaped, fimbriate, unicellular gall. Distribution — United States. Reference — Felt, E. P. New York State Mus. Bui. 200: 138. 1918. pomonella Walsh, Rhagoletis (Apple maggot) Fam. Trypetidae Hosts — -Crataegus, Malus, Vaccinium, Symphoricarpos. Injury — ■ Larva tunnels in fruit. Distribution — ■ Eastern North America. References — Walsh, B. D. First annual report on noxious insects of Illinois, p. 30. 1868. O'Kane, W. C! New Hampshire Agr. Exp. Sta. Bui. 171. 1914. Severin, H. H. P. State Comm. Hort. California. Mo. bul. 7:430. 1918. venae Felt, Lobopleromyia (Thorn vein gall) Fam. Cecidomyiidae Host — Crataegus. Injury — ■ Larva causes oval, smooth, fleshy gall, 5 to 8 mm. long, on leaf vein. Distribution — United States. Reference — Felt, E. P. New York State Mus. Bul. 200 : 138. 1918. (Figs. 118 and 119, page K)S3.) venitalis Felt, Dicrodiplosis Fam. Cecidomyiidae Host — ■ Crataegus. Injury — Larva found in same gall with Lobopteromyia venae. Distribution — United States. Reference — Felt, E. P. New York State Mus. Bul. 200 : 138. 1918. Cecidomyia sp. (a. 2727 Felt) Fam. Cecidomyiidae Host — Crataegus. Injury — Larvae cause subglobose, greenish, sometimes confluent, frequently pointed, polythalamous vein galls, the under side reddish, diameter 3 mm. Distribution — United States. Reference — Felt, E. P. New York State Mus. Bul. 200 : 138. 1918. Cecidomyia sp. (a. 1840 Felt) (Thorn spindle gall) Fan. Cecidomyiidae Host — Crataegus. Diptera — Hymenoptera 1 131 Injury — Larva causes a spindle-shaped thickened gall on leaf vein, green or reddish, length 1 cm., diameter 2 mm. Distribution — Eastern United States. Reference — Felt, E. P. New York State Mus. Bui. 200:138. 1918. (Figs. 120 and 121, page 1084.) Hymenoptera betuleti Klg., Trichiosoma Fam. Tenthredinidae Synonyms — Cimbex crataegi Wd., Trichiosoma tibialis Steph. Host — Crataegus. Injury — Larva eats foliage. Distribution — Europe. efer nces — Kaltenbach, J. H. Pflanzenfeinde, p. 211. 1872. Andre, Ed. Species des Hymenopteres d' Europe, 1:27. 1879. cerasi Linn., Caliroa (Pear and cherry slug) Fam. Tenthredinidae Hosts — Prunus, Crataegus, Pyrus. and other species. Injury — Larvae skeletonize leaves. Distribution — Europe, North America, Australia. References — Slingerland, M. V., and Crosby, C. R. Manual of fruit insects, p. 214. 1914. MacGillivray, A. D. Hymenoptera of Connecticut, p. 79. 1916. cotlaris MacG., Profenusa (Cherry and hawthorn sawfly leaf miner) . . Fam. Tenthredinidae Hosts — Crataegus, Prunus cerasus. Injury — Larva mines in leaf, causing brown blister which may cover from a quarter to the whole of the upper surface of the leaf. Distribution — Massachusetts, New York. Reference — Parrott, P. J., and Fulton, B. B. New York (Geneva) Agr. Exp. Sta. Bui. 411. 1915. druparum Boh., Syntomaspis (Apple seed chalcid) Fam. Chalcididae Hosts — Malus, Pyrus, Sorbus, Crataegus. Injury — Oviposition punctures cause dimples in fruit, and larvae destroy seeds. Distribution — Europe, North America. References — Schlechtendall, D. von. Ztschr. Naturwiss. Halle 61 : 41.5. 1888. Cushman, R. A. Journ. agr. res. 7:487. 1916. Woodruffe-Peacock, E. A. Naturalist (London), no. 753, p. 329. 1919. flaviventris Retz., Lyda Fam. Tenthredinidae Synonym — Lyda clypeata Klg. Hosts — Crataegus, Pyrus. Injury — Larvae defoliate branches, feeding in colonies. Distribution — Europe. References — Kaltenbach, J. H. Pflanzenfeinde, p. 206. 1872. Andre, Ed. Species des Hymenopteres d'Europe, 1 : 516. 1879. humeralis Fourc, Cimbex Fam. Tenthredinidae Synonym — Cimbex axillaris Pz. Hosts — Crataegus, Prunus padus. Injury — Larva feeds on foliage. Distribution — Europe. References — Kaltenbach. J. H. Pflanzenfeinde, p. 212. 1872. Andre, Ed. Species des Hymenopteres d'Europe, 1:24. 1879. 1132 Hymenoptera padi Linn., Priophorus Fam. Tenthredinidae Hosts — Crataegus, Pyrus, Prunus, Malus, Sorbus, and other species. Injury — Larva skeletonizes leaves. Distribution — Europe. References — Andre, Ed. Species des Hymc'nnpteres d'Europe, 1:84. 1S7'.). Collinge, W. E. Manual of injurious insects, p. 219. 1912. punctum-album Linn., Macrophya Fam. Tenthredinidae Hosts — Fraxinus, Ligustrum, Crataegus. Injury — Larva feeds on foliage. Distribution — Europe. Reference — Andre, Ed. Species des Hymenopt ?res d'Europe, 1 : 359. 1879. Four species of unidentified sawflies (pages 1086 and 1087.) INDEX OF GENERA AND SPECIES (Synonyms are in italics) A PAGE Acalla oontaminana 1113 holmiana 1 1 IB Acrobasis nebviella 1117 Acronycta americana 10 '3. 1109 dactylina LO/3, 1114 euphorbiae 1115 luteicoma 1073, 1 1 19 occidentalis.. . 1074, 1120 j. si . 1123 radcliffei 1074, 1124 strigosa 1 126 superans 1074, 1127 tridens 1127 Aegeria pyri 1 124 Agrilus politus 1 106 sinuatus 1 108 vittaticollis 1050, 1 108 Agriotes pubescens 1066, 1107 Alsophila pometeria 1076, 1 122 Alticopus galeazii 1 107 Amphidasis betularia 1111 Amphipyra pyramidea 1123 pyramidoides 1074, 1123 Ancylis nubeculana 1077, 1120 selenana 1 12.5 tineana 1127 Anisopteryx aescularia 1109 Anthaxia quercata 1 107 Anthonomopsis mixtus 1105 Anthonomus decipiens 1 103 flavicornis 1 104 nebulosus 106S, 1105 pomorum 1 106 profundus 1 106 Aphis tivenae (Amer. authors) 109S avenae Fabr • 1097 bakeri 1092 brevis 1092 crataegi Buck 1094 crataegi Kalt 1093 crataegi Koch 1093 crataegiella 1094 crataegifoliae 1064, 1094 crataegus-coccinea 1094 edentula.. 1095 Mchii 109S mali L098 malifoliae 1099 marutae 1096 oxyacanthae Koch 1097 oxyacanthae Schr 1098 padi 1097 pomi 1065, 1098 pyri 1093 ranunculi 1093 rumicis 1099 sorbi 1099 Apion pomonae 1 106 Aporia crataegi 1113 Archips argyrospila 1077, 1110 Argvreithia ephippella 1 115 nitidella 1120 oreasella 1078, 1121 PAGE Argyresthia pruniella . . . .1115 Argyroploce pruniana. . . . 1123 Aspidiotus hederae . 1095 nerii 1095 ostreiformis 1097 oxyacinth le , 1097 perniciosus 1065, 1098 piri . .... 1098 Asteroscopus cassinii . 1126 Automeris io 1073, 11 17 B Basilarchia arthemis 1110 astyanax 1110 Blastodacna curvilineella. . . 1080, 1114 hellerella 1116 Bracliionycha sphinx 1126 Brachys aerosus 1066, 1101 Bucculatrix crataegi . . 1113 pomifoliella 1079, 1122 Byturus tomentosus 1 108 C Cacoecia crataegana 1113 rosaceana 1078, 1 12.5 rosana 1125 Caliroa cerasi 1086, 1131 Calligrapha multipunctata .■ 1105 Calymnia trapezina 1127 Capsus medius 1097 Capua angustiorana 1 109 Catocala blandula 1111 crataegi 1113 fulminea - 1115 paranympha 1115 polygama 1122 Cecidomyia bedeguar 1129 sp. (a. 1840 Felt) 10S2, 1130 sp. (a. 2727 Felt) 1130 Cemiostoma scitella 1 125 Ceratocapsus pumilus 1099 ( !eresa bubalis 1092 taurina... 1063, 1 100 Ceroplastes rusci 1099 Chalepus dorsalis 1103 Chariptera viridana 1 128 Cheimatobia brumata 1111 Chermes quercus 1094 Chionaspis furfura, 1065, 1095 Choragus scheppatftli 1 107 Chrysobothris feinBrata 1050, ] 103 Cilex glaucatus 1116 Cimbex axillaris 1131 crataegi 1131 humeralis 1 131 Onephasia nubilana 1120 Coleophora anatipennella 1109 fletcherella 1079, 1 115 hemerobiella 1116 malivorella 1079, 1119 tiliella 1109 Conotrachelus crataegi 1051, 1068, 1103 1133 1134; Index PAGE Conotrachelus naso 1105 nenuphar 1 105 posticatus 1 106 Contarina anthobia 1129 Coptodisca splendoriferella 1079, 1126 Corythucha arcuata 1095 bellula 1056, 1092 brunnea 1092 crataegi 1095 cydoniae 1095 Crambus oxyacanthae 1115 Crepidodera helxines 1067, 1101 Cryptocephalus bipunctatus 1050, 1101 Cydia pomonella 1 122 D Dasychira pudibunda Ill3 Datana integerrima 1117 ministra , .. 1075, 1119 Deraeocoris olivaceus 1097 Diaphnidia pellucida 1055, 1098 Diaspis piri 1092 Dibolia borealis 1067, 1 102 Dichelia grotiana 1116 Dichelonycha elongata 1066, 1103 testacea 1067, 1108 Dicrodiplosis venitalis 1130 Diloba coeruleocephala 1112 Diphucephala colaspidoides 1102 E Eecoptogaster pruni 1106 rugulosus 1107 Empoa querci 1062, 1099 rosae 1099 Empoasca mali 1061, 1096 Ennomos magnarius 1076, 1119 subsignarius 1076, 1127 Epetrimerus armatus 1090 Epiblema biscutana 1111 Epicnaptera americana 1075, 1109 Epidiaspis betulae 1092 leperi 1092 piricola 1092 Epigraphia steinkelneriana 1126 Epitrix cucumeris 1067, 1103 Erineum clandestinum 1090 oxyacanthae 1090 Eriogaster catax 1111 lanestris 1117 Eriophyes calycobius 1090 crataegi 1090 crataegi-vermiculus 1090 goniothorax 1053, 1090 pyracanthae .j 1090 . pyri M 1090 sp. No. 1 '. 1052, 1091 sp. No. 2 1053 sp. No. 3 1053 Eriosoma crataegi 1096 lanigera 1051, 1064, 1096 Erranis tiliaria 1076, 1127 Erythroneura obliqua 1061, 1097 Eulecanium pyri 1093 Eulia quadrifasciana 1078, 1124 Euproctis chrysorrhea 1112 Eupteryx vanduzei 1062, 1100 Euscelis curtisii 1061, 1094 Eutettix seminudus 1062, 1099 Euthrips tritici 1066, 1100 Exapate congelatella 1112 G PAGE Gastropacha quercifolia 1124 Gelechia spurcella 1 126 vulgella 1 1^8 Glossonotus crataegi 1063, 1093 Gonodontis bidentata 1111 Graphocephala coccinea 1061, 1093 Grapholitha janthinana 1117 kroesmanniana 1 125 H Halisidota caryae 1073, 1111 tesselaris 1073, 1127 Haltica carinata 1067, 1102 foliacea 1 104 Hemaris thysbe 1 127 Hemerocampa leucostigma 1075, 1118 vetusta 1128 Hemithea strigata 1 126 Hercyna palliolalis 1 1 14 Heterocampa manteo 1074, 1 1 19 Heterocordylus malinus 1051, 1054, 1096 Hibernia aurantiaria 1110 bajaria 1110 defoliaria 1114 leucophaearia 11 18 marginaria 1 1 19 Holcophora fasciellus 1115 Horcias dislocatus 1051, 1095 Hormomyia crataegifolia 1082, 1129 Hyphantria textor 1073, 1127 Hyponomeuta padella 1121 I Idiocerus crataegi 1094 fitchi 1061, 1095 lachrymalis 1061, 1095 rnaculipennis 1095 pallidus 1062, 1098 provancheri 1062, 1098 suturalis 1062, 1100 Idiostet hus tubulatus 1 108 L Lamenia vulgaris 1063, 1100 Lasiocampa quercus 1124 Lasioptera excavata 1130 Laspeyresia prunivora 1051, 1078, 1123 Lecanium bituberculatum 1092 capreae 1093 corni 1065, 1093 coryli 1093 nigrof asciatum 1097 pruinosum 1098 Lepidosaphes ulmi 1065, 1 100 Lestes viridis 1048, 1091 Lestodiplosis crataegifolia 1080, 1130 Limnobaris calva 1102 Limonius dubitans 1066, 1103 Liparis auriflua 1 125 Lithocolletis betulae 1110 cerisolella 1112 concomitella 1112 corylifoliella 1113 crataegella 1113 malimalifoliella 1119 oxyacanthae 1121 pomifoliella 1112 prunivorella 1116 Lobopteromyia venae 1082, 1130 I Lophopteryx cuculla. . : 1114 JttLyeia cognataria 1076, 1112 Index 1135 PAGE Lyda clypeala 1131 flaviventris 1131 Lygidea mendax 1051, 1055, 1096 Lygus communis 1054, 1093 ostryae 1055, 1097 pratensis 1055, 1098 univittatus 1055, 1100 Lymantria dispar 1114 Lyonetia clerkella 1112 M Macrodactylus subspinosus 1108 Macrophya punctum-album 1132 Macrosiphum crataegarium 1093 crataegi 1063, 1094 Magdalis aenescens 1 101 barbicornis 1101 cerasi 1 102 nitidipennis 1 105 pruni 1 106 Malacosoma americana 1075, 1 109 disstria 1114 neustria 1 120 , Melanoplus atlanis 1054, 1091 bivittatus 1054, 1091 femur-rubrum 1054, 1091 Melanotus sp 1066, 1108 Melinna pumila 1099 Mesoleuca lacustrata 1117 Mineola indigenella 1077, 1117 Miselia oxyacanthae. 1121 Mycodiplosis cerasifolia 1129 Mytilaspis pomoram 1100 Myzus oxyacanthae 1097 N Naeophora quernaria 1124 Nematocampa filamentaria 1118 limbata 1 1 18 Nemoria aestivaria 1126 porrinata 1 122 viridata 1128 Nepticula aterrima 1110 atricollis 1110 crataegifoliella 1114 gratiosella 1116 ignobilella 1117 nitidella 1120 oxyacanthella 1 121 prunetorum 1 123 pygmaeella 1 1 23 regiella 1124 scintillans 1 125 Nola cucullatella 11 14 Notocelia suffusana 1 127 Notodonta ciicidlina 1 1 14 Notolophus antiqua 1110 O Oecanthus niveus 1048, 1091 Olethreutes achatana 1109 chionosema 1077, 1112 variegana 1128 Ophiderma flavicephala 1063, 1095 Ophiusa tirrhaea 1127 Opisthograptis luteolata 1119 Orchestes rufus 1 107 Urnix anglicella 1 109 crataegifoliella 1 114 geminatella 1116 PAGE Ornix inusitatumella 1117 Orthotylus ornatus 1055, 1097 Otiorrhynchus caudatus. . . . 1102 crataegi .1 103 Ovatus mespili 1096 P Paleacrita vernata 1076, 1128 Pamene rhediella 1124 spiniana 1126 Pandemis heparana .1116 ribeana 1 125 Paonias myops 1 1 19 Papilio podalirius 1122 turnus 1072, 1128 Parlatoria oleae 1097 Pemphigus corrugatans 10! 3, 1093 Penthina robrana 1113 Perrisia circumdata 1129 crataegi. 1129 Phenacoccus aceris 1091 betheli 1095 dearnessi 1095 Phigalia pedaria 1121 titea 1076. 1127 Philaenus lineatus 1061, 1096 Phycita nebulo 1117 Phyllobius maculicornis 1104 oblongus 1 105 Physatocheila dumetorum 1095 Pineapple gall (maker unknown) 1085 Platysamia cecropia 1111 Poecilocampa populi 1122 Polydrusus impressifrons 1104 pterygomalis 1107 sericeus 1107 Porthesia similis 1125 Priophorus padi 1132 Prociphilus crataegi 1094 pyri 1099 Prodenia praefica 1122 Profenusa collaris 1 . 1131 Psallus ambiguus 1091 Pseudanthonomus crataegi 1103 Pseudophia tirhaca 1 127 Psylla costalis 1093 crataegi Schr 1094 crataegi Forst 1096 crataegicola Flor 1098 crataegicola Forst 1096 mali 1049, 1096 melanoneura 1096 peregrina 1098 saliceti 1099 Pulvinaria betulae 1100 innumerabilis 1100 oxyacanthae 1100 vitis. . 1065, 1100 Pyrausta purpuralis 1 123 R Ramphus flavicornis 1 104 oxyacanthae 1 104 Recurvaria r.rataegella 1120 leucatella 1118 nanella . .. 1051, 1120 Rhagoletis pomonella 1059, 1085, 1130 Rhizomyia absob.ina 1080, 1129 hirta 1130 Rhodophaea advenella 1 109 Rhopalosiphum pad:. 1097 1136 Index PAGE Rhopalosiphum prunifoliae 1065, 1098 Rhopobota naevana 1 120 Rhynchites aeneovirens var. punetatus 1100 aequatus 1101 auratus 1101 bacchus Linn 1 101 bacchua Oliv 1101 coeruleocephalus 1 102 comntus 1 105 ronicus 1 1 04 cyanicolor 1107 giganteus 1 104 icosandriae 1 104 olivaceus 1 105 ophthalmicus 1 10S pauxillus 1 105 pubescens 1 107 sericeus 1 108 Rosalia alpina 1 101 Uumia crataegata 1119 s Saperda bivittata 11C2 Candida 1102 cretata 1 103 favi 1103 Sawfly No. 1 1086, 1132 Saw-fly No. 2 1086, 1132 Sawfly No. 3 1086, 1132 Sawfly No. 4 1087, 1 132 Schizoneura americana 1096 Sehizura concinna 1074, 1112 unicornis 1 128 Scythropia crataegella 1113 Selenia lunaria 1118 Sesia pyri 1 124 scitula 1076, 1125 Sibine stimulea 1126 Simaethis fabriciana 1115 pariana 1051, 1121 Sphecodina abbotti 1108 Steganoptycha signatana 1125 Strymon calanus 1111 liparops 1118 melinus 1119 Swammerdamia lutarea 1118 oxyar.anthelln 1118 Syneta albida 1 101 PACE Syntomaspis druparum 1131 Systena marginalia 1067, 1105 T Tachypterus quadrigibbus 1072, 1107 Taeniocampa gothica 1116 incerta 1 1 17 instabilis 1117 Telea polyphemus 1 122 Tephroclystia vulgata 1 128 Tetraneura ulmi 1100 Tetranyehus pilosus 1090 telarius: 1051, 1091 Thamnotettix clitellarius 1061, 1092 Thecla /filacer 1111 Thyridoptoryx ephemeraef ormis 1115 Tinea oxyac.nnthella 1115 Tischeria malifoliella 1 1 19 Tmetoeera ocellana 1078, 1120 Tortrix incisana 1 1 17 laevigana 1 125 Trichiosonia betuleti 1131 tibialis 1 131 Trichiura crataegi 1114 Trichosea ludifica 1118 Trioza urticae 1 1 00 Triphosa dubitata 11 15 Trochilium myopiforme 1119 Typhlocyba crataegi 1094 Tymnes metasternalis 1 105 V Valeria oleagina 1121 W Winnertzia hudsoniei 1130 X Xanthoma villosula 1067, 1108 Xylotrechus convergeus 1102 Y Yponomeuta cognatellus 1112 padellus 1051, 1121 Z Zeuzera aesculi 1124 pyrina 1124