Bulletin Ni\ 25 New Series. 
 
 U. S. I)K]\\RTiMl{N T Oi^ ACiRiCUiyrURK. 
 DIVISION OF kntomoi.o<;y. 
 
 NOTES 
 
 nf\p 
 
 >>' 
 
 THE MOSQUITOES OF THE UNITED STATES 
 
 GIVING SOME ACCOUNT OF THEIR STRUCTURE AND BIOLOGY, 
 WITH REMARKS ON REMEDIES. 
 
 BY 
 
 L. O. HOWARD, Vw. W 
 
 f-^^^ 
 
 ££^s;t5rH ' 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING- OFFICE. 
 1900. 
 
Bulletin No. 25— New Series. 
 
 U. S. DEPARTMENT OV AC;RICULTURE. 
 
 DIVISION OF KNTOMOLOGY. 
 
 NOTES 
 
 ON 
 
 THE MOSQl]ITOES OF THE UNITED STATES 
 
 GIVING SOME ACCOUNT OF THEIR STRUCTURE AND BIOLOGY. 
 WITH REMARKS ON REMEDIES. 
 
 BY 
 
 L. O. HOWARD, Ph. D. 
 
 Entomologist. 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE. 
 1900. 
 
DIVISION OF EXrOMOLOGY. j 
 
 EutomologlKt: L. O. Howard. * 
 
 7*7 />V Asftistant Entomologist: C. L. Marlatt. : 
 
 Asfiiatant E)itomologi.<its: Th. Pergande, F. II. Chittenden, Frank Benton. ' 
 
 Inveatigntorx: E. A. Sohwarz, 1). W. Coquillett. ■ 
 Amstantx: R. S. Clifton. Nathan Bank^!', F. C I'ratt, Aug. lUiyck, Otto Ileidemann, j 
 
 A. N. Caudell, J. Kotinsky. j 
 
 Artist: Mii<s L. SulHvan. « 
 2 
 
LETTER OF TRANSMITTAL. 
 
 U. S. Department of Agriculture, 
 
 Division of Entomology, 
 Was/iinc/ton, D. C, July ^^, 1900. 
 Sir: I have the honor to transmit herewith manuscript of a bulletm 
 on the mosquitoes of the United States, which gives some account of 
 their structure and biology and indicates the diiferences in all stages 
 of existence between the kinds of mosquitoes which have been shown 
 to transmit malaria and those which do not. It also treats of the sub- 
 ject of remedies in considerable detail. It has been written mainly 
 from the popular standpoint, although scientific details of structure 
 and classification have been inserted for the use of ph3\sicians engaged 
 in studying malaria. I recommend that it be published as Bulletin No. 
 25, New Series. 
 
 Respectfully, L. O. Howard, 
 
 Entomologist. 
 Hon. James Wilson, 
 
 Secretary of Agriculture, 
 
 2 
 
INTROIUKTIOX. 
 
 A number of articles and notes concern i no- mosquitoes have been 
 published in ditt'erent bulletins of this Division. The most extensive 
 was the leading article in Bulletin No. 4, New Series ("The Principal 
 Household Insects of the United States''), and constituted the larger 
 part of chapter!, on ''Mosciuitoes and Fleas." In this treatment of 
 mosquitoes the complete life history of C i ilex pun f /ens was given, based 
 upon original o])servations made in the summer of 1895, and some gen- 
 eral remarks on the subject of other species were brought together. 
 Four pages were devoted to the subject of remedies, and the mosquitoes 
 of the (H)untry at large were tabulated, with such notes on geogi'aphical 
 distriljution as could ))e l)rought together. The earlier notes pub- 
 lished by the Division, including those extracts from correspondence 
 and general notes which had been published in the seven A^olumes of 
 Insect Life, and the writer's two articles on the use of kerosene against 
 mosquito larvae, were all digested in this bulletin, which was published 
 in the summer of 1896. Subsequent brief notes on remedies have been 
 published l)y the writer in miscellaneous bulletins of the Division and 
 in the Scientilic American, and the life history of Anojjheles ([uadrima- 
 culatus was described, in comparison with that of Cale.i' jmiigenH, in a 
 short illustrated article in the Scientitic American for eluh" 7, 1900. 
 
 The writer first became interested in mosquitoes thirty years or 
 more ago, Avhen as a boy he fished and collected insects in the marshes 
 at the head of Cayuga Lake, New York, and as early as 1867 had 
 experimented with the kerosene remedy against mosquito larva? in a 
 horse trough at Ithaca. In 1881 he discussed with Dr. A. F. A. King and 
 the late C. V. Riley the l)earings of the theory, which Dr. King was 
 the first to bring forward in the United States, of the probable rela- 
 tion between mosquitoes and malaria, both Dr. Riley and the writer 
 contending, it must be confessed, that the arguments brought forward 
 h\ Dr. King in conversation were leased upon coincidental observations, 
 and afforded no good proof of cause and effect. 
 
 The writer's practical demonstration in 1894 of the value of the 
 kerosene treatment as a practical large-scale remedy attracted consid- 
 erable attention to the subject of remedies for mosquitoes, and man}^ 
 large-scale experiments were made, some of them being successful to 
 a marked degree, as will be pointed out later in the section on rem- 
 edies. The services of the members of this office force were called 
 
 5 
 
into n'ijuisition on a number of occixsions to (Ictennino acluiil brooding 
 points in niosijuito-infcstod regions, and interest in the subjeet gmd- 
 ually increased until, during the past two or three years, the researches 
 of th<>se medical nu'ii. whose names have since liecome so well known 
 in this ((Mincction, showed hy exact methods that Dr. King's theory 
 nui>t IK) longer b«' considered u theory but a demonstrated fact. It 
 has resulte<l that the attention of the entire civilized world has l>een 
 drawn with vivid interest toward the wh(>le mosquito question. Ever}' 
 fact <(nicerningmos(piitoes becomes now of great potential importunce. 
 The correspoiuh'nce of this office on moscjuitoes. owing largely to its 
 publications, has become greatly increased. The writer has been 
 invit«'(l to address scientific bodies and citizens' improvement associa- 
 tions on the subject of mos(juito extermination, and in the spring of 
 tlu' present year lectured before the annual meeting of the Koyal 
 Society of ( anada and ])efore the section on theory and practice of 
 medicine of the American Medical Association on the subject of the 
 ])iol()gy of the moscjuitoes of the genus Anopheles as contrasted with 
 that of the moscputoes of the genus Culex. The demand for the pub- 
 lications of this Division on mosquito subjects has been so great that 
 it has been deemed desirable to bring together the published and 
 unpublished articles and notes in convenient reference form from the 
 standpoint of the liiited States only, and this has been done in the 
 prt sent bulletin. 
 
 The writtu- is inde))ted to his assistants, Mr. D. W. Coquillett, for 
 determinations of the diti'erent mosquitoes discussed; Mr. F. C. Pratt, 
 for untiring efforts in the collection of material; Mr. August Busck, 
 Mr. K. S. Clifton, and Mr. J. Kotinsky. for assistance in laboratory 
 ex])eriments, and Miss L. Sullivan, for the preparation of the illustra- 
 tions. Information and specimens derived from many correspondents 
 are acknowledged in the pages of the bulletin. 
 
 L. O. H. 
 
CONTENTS. 
 
 Page. 
 
 On mosquitoes in irenoral 9 
 
 Abundance of mosquitoes *> 
 
 Alaskan and other far-northern mosquitoes 10 
 
 Length of Hfe of the adult mosquito 11 
 
 Life history of mosquitoes in general 12 
 
 Food of adult mosquitoes 12 
 
 How far will mosquitoes fly? 13 
 
 Carriage of mosquitoes by railway trains 14 
 
 How long can the larvae live out of water? 15 
 
 The number of species of mosquitoes 17 
 
 Mosquitoes and malaria 17 
 
 Synoptic tables of the North American mosquitoes 18 
 
 Generic synopsis 19 
 
 Genus Culex 19 
 
 (a) Eecognized species 19 
 
 (b) L'nrecognized species 20 
 
 Genus Anopheles 21 
 
 (a) Recognized species 21 
 
 (b) Unrecognized species 21 
 
 Genus Psorophora 22 
 
 Genus ]\Iegarhinus 22 
 
 Genus Aeies 22 
 
 The biology of Culex, with remarks on some of the species 22 
 
 Life history of Culex pungens 22 
 
 Remarks on other species of Culex 28 
 
 The distribution of the species of Culex in the United States 29 
 
 The biology of Anopheles, with general remarks 31 
 
 Life history of Anojjheles quadrimacidatus 32 
 
 The adult 32 
 
 Resting position 33 
 
 Xote of female 34 
 
 The eggs 35 
 
 The larva 36 
 
 The pupa 40 
 
 Natural breeding places of Anopheles 41 
 
 Other species of Anopheles 43 
 
 Distribution of the species of Anopheles in the L'nited States 44 
 
 The genus Psorophora 45 
 
 The genus Megarhinus 47 
 
 The genus Aedes 47 
 
 The natural enemies of mosquitoes 48 
 
 Remedies against mosquitoes 49 
 
 Remedies in houses and iirevention of bites 49 
 
 Remedies for bites 51 
 
8 
 
 Page. 
 
 iV.wtruotion of larvn- ami alM»lition ..f l.rrt>«rm^ jjlaoes 51 
 
 KtTosnn' «in l»n-«Mlin;.' ixuds 51 
 
 I )iaiiiagt* 53 
 
 IVa(ti«al UK' ..f lisli 54 
 
 ArtiJu'ial :i^itati<ni <»t tin* water 54 
 
 I.at<'r us** « tf ktn istMU' 55 
 
 OthtT larvifitlt's 57 
 
 l***riuaiigauatc of i»(4a>;li ... 57 
 
 I'roprit'tary iiiixturi'S 5M 
 
 KxiKTiiiu'iits of (\*Hi ari<l CaHiigraiuli 58 
 
 Tar ami itH toiii|M»iiii<ls 60 
 
 Kiualyi»lusln*»'s 62 
 
 l)niiiiajz«' and «<»iiiiimnity work 63 
 
 A|»|M*inlix 66 
 
 LUSTRATIONS. 
 
 Pagt 
 
 Fi<;. 1. ('nk'X piingen^i: Eggs and vom>«r larva' 
 
 2. CuK'x ]>iingfiis: lli-ad and nioiith jiarts of larva 
 
 .'>. C'ulex jxingt'HH: Full-grown larva and i>uj)a 
 
 4. CuK'X ])ungens: Adults, mak' and ft'iiiah', with structural details 
 
 '). CuK'X ta-niofliynchus: Female 
 
 (>. Anojiludes (juadriinaculatus: Adult male and female 
 
 7. Resting i>ositiuns of Culex and Anopheles eomparetl 
 
 Resting positions of Anopheles on vertical and horizontal walls 
 
 Resting i)ositions of Anopheles an<l Culex, after Waterhouse 
 
 Anoi)heles (piadrimaculatus: Egg mass 
 
 Anoi)heles (juadrimaculatus: Isolated eggs from al)Ove and l^elow 
 
 Anopheles (piadrimaculatus: Newly hatched larva' 
 
 IIalf-gr»»wn larvje of Anopheles (juadrimaculatus contrasteil with same 
 stiige of Culex jmngens 
 
 Feeding jiosition of larva of Anopheles (juadrimaculatus contrasted 
 with that of Culex jiungens 
 
 Anoi>heles (juadrimaculatus: Full-grown larva, showing head from 
 ahove and below 
 
 Anojyheles (juadrimaculatus: Fujta contrasted with that of Culex 
 pungens 
 
 Anopheles punctij)ennis: Head of full-grown larva fr(»m alv)ve 
 
 Anoplieles j)unctii)ennis: Adult female 
 
 Ano]>heles crucians: Adult female 
 
 Psorophora ciliata: Adult female 
 
 Megarhinus rutilus: Adult female 
 
 Aedes sapphirinus: Adult female 
 
 8. 
 
 9. 
 10. 
 11. 
 12. 
 
 i::' 
 
 14. 
 
 ir>. 
 
 k;. 
 
 17. 
 IS. 
 
 19. 
 
 20. 
 
 21. 
 
 23 
 24 
 26 
 27 
 28 
 32 
 33 
 34 
 34 
 35 
 35 
 36 
 
 37 
 
 38 
 
 39 
 
 40 
 41 
 
 4:; 
 
 44 
 45 
 4() 
 47 
 
NOTES ON THE MOSOUITOES ()!• THE UNITlil) 
 
 STATES. 
 
 ON MOSQUITOES IN (iENERAL. 
 
 Ahimdance of rno^quitoe^. — The literaturo of popular cntomolooy is 
 full of iiLstances of the enormous numbers in which mosquitoes occa- 
 sionally occur. Persons interested in this line of curious reading 
 should consult Kirby and Spence's An Introduction to Entomology, 
 Volume 1. pages 112-120, and Frank Cowan's Curious Facts in the 
 History of Insects, pages 278-286. Referring to their occurrence in 
 the far northern regions, Kirby and Spence, for example, say: "In Lap- 
 land their numf)ers are so prodigiou.s as to be compared to a flight of 
 snow when the flakes fall thickest or to the dust of the earth. The 
 natives can not take a mouthful of food or lie down to sleep in their 
 cabins unless the}^ be fumigated almost to sutiocation. In the air you 
 can not draw^ your breath without having your i»outh and nostrils 
 filled with them, and unguents of tar, fish grease, or cream, or nets 
 steeped in fetid birch oil are scarcely sufficient to protect even the case- 
 hardened cuticle of the Laplander from their bite." Elsewhere the 
 same authorities say: ''In the neighborhood of the Crimea the Russian 
 soldiers are obliged to sleep in sacks to defend themselves from the 
 mosquitoes, and even this is not a sufficient security, for several of 
 them die in consequence of mortification produced by the bites of these 
 furious bloodsuckers." Elsewhere: "And Captain Stedman, in Amer- 
 ica, as a proof of the dreadful state to which he and his soldiers were 
 reduced by them, mentions that thev Avere forced to sleep with their 
 heads thrust into holes made in the earth with their bayonets and 
 their necks wrapped round with their hammocks." Humboldt says: 
 "Between the little harbor of Higuerote and the mouth of the Rio 
 Unare the wretched inhabitants are accustomed to stretch themselves 
 on the ground and pass the nights buried in the sand 3 or ^ inches 
 deep, leaving out the head only, w^hich the}^ cover with a handker- 
 chief." Theodoretus saj^s that Sapor, King of Persia, was compelled 
 to raise the siege of Nisibis b}^ a plague of gnats, which attacked his 
 elephants and beasts of burden and so caused the rout of his army. 
 
 In modern times nearly every hunter and fisherman in this country 
 has had experience with mosquitoes which renders easy of belief all 
 of the old-time stories. The instance mentioned in Bulletin No. 4, of 
 
 y 
 
10 
 
 tho ()))S('rvsitions ])y Mr. St'hwiuz, of this office, at Corpus Christi, 
 Tfx., could l)c practicjilly tluplicjitcd ))y uiany persons. He showed 
 that when th«' wind })h)ws from any other direction than south '' hun- 
 dreds of thousands of millions" of moscjuitoes l>h)W in upon the town. 
 Great heids of hundreds of horses i*un hefoi-e the mosipiitoes in order 
 to get to the uatri . W'itli a chanj^t^ of wind, however, the mosquitoes 
 bh^w away. Many rt'oions, especially alon*»' the seacf)ast, have been 
 actually i-ciidcred uiiinlialntahle liy the abundance of mosijuitoes, and 
 they li:i\«' IxMii a serious draw}>ack to the settlement of many other- 
 wis«' ad\ aiita«^cous and fertile localities. 
 
 I)r. Otto Luii'i'er rc})oi'ts, on patres tilO,21T of iiis annual rt'port for 
 18JM) as «'Mtouioloti-ist to the Minnesota State Ag-ricultural Kxperiment 
 Station, an interestinti" sci'ies of ol)s«'rvations to det<'rmine the number 
 of mos(juito('s which may be bred in an ordinary rain barrel. The 
 obsi'iN ations nncic made at St. Anthony Paik. Minnesota. On July 0, 
 181K), the watc'r in one barr»d was filtered and was found to contain 
 17,!i51* egtrs, larva', and pupa'. On July :i'2^ Isi)*;, by a similar proc- 
 ess, lt*,ll(l mosijuitoes were counted. When we consider that at 
 least twelve generations may breed in a summer it is obvious, from 
 Dr. Luggers accoimt, tliat a neighborhood may be well supplied 
 from one neglected rain-water barrel. 
 
 Ahtshui (1 11(1 other f (I r tKN'th^rn in(tsq}i!to<x. — Since the opening up 
 of the gold fields in Alaska and the great influx of miners and traders, 
 knowledge of the abundance and ferocity of the Alaskan mosquitoes 
 has become widespread, and surveying parties from the United States 
 Coast and Oeodetic Survey and the UniUnl States Geological Surve\^ 
 in starting for Alaska for their sunuiier\s work are in the habit of con- 
 sulting this office for the best remedies for mosquito bites. Those 
 who were in Alaska the preceding year always state that they never 
 experienced or even imagined anything in the mosquito line quite equal 
 to those found in our northern territory. Mr. AV. C Henderson, of 
 Philadelphia, who spent some time in Alaska recently, writes: ''They 
 existed in countless millions, driving us to the verge of suicide or 
 insanity." Nothing has as yet been pu))lished regarding the exact 
 species found in Alaska, ))ut Mr. Co({uilleft has determined CuJt-.r cofi- 
 snh?'/ /nts iind Cff/u' ////y>/V/r/' from specimens collected by Prof. Trevor 
 Kincaid on the Ibirriman exi)edition of ISt)}). 0. crmsithi'lnus was 
 collected at Sitka June hi. and Yakutat June 21: and (\ J//tjfi(/rr Vi^BS 
 taken at Sitka June 1(), Vakutat ,June iM, Virgins Hay June 2tK and 
 Popotl" Island July S-U\. 
 
 That the knowledge of the existiMice of moscjuitoes in boreal regions 
 is not new is shown by the (juotation just made from Kirby and Spence, 
 and in Bullet iri No. 4 the writer mentioned some of the instances of 
 record by arctic exploi'ers, citing, for exanqJe, the narrative of C. F. 
 Hair^ second arctic expedition, in which the stiitement is made that 
 
11 
 
 mosquitoes appoarod on tho 7th of July. 1S01>, 'm extraordinary 
 abundanrc. and of Dr. K. Storlint^, of C'l('\(dand, Ohio, who sent us an 
 aeeount of the appeanmee of mosqaitoes ])y thousands in ]Mareli, 1S44, 
 when lie was on a snowshoe trip from Mackinaw to Sault Ste. !Marie. 
 Their extraordinary appearance at that si»ason of the ycMir was remark- 
 able as indicating- a most plentiful hibernation. Mr. II. Stewart, of 
 North Carolina, was also cpioted as noticing, on the north shore of 
 Lake Superior, in 18r»(), in the warm days of ^larch, when the snow^ was 
 several feet deep and the ice on the lake T) feet in thickness, that mos- 
 quitoes appeared in swarms, "literally blackening the banks of snow 
 in the sheltered places." Dr. Otto Lugger was also ipioted as stating 
 that Calex coiisohrhim made its appearance in April, 1896, at St. 
 Anthony Park, Minnesota, in a genuine swarm with a heavy snow-- 
 storm, at a time w^hen all the lakes w^ere covered with ice. 
 
 Dr. Lugger has also called the w riter's attention to the fact that Dr. 
 Emile Bessels, of the Polaris expedition, was obliged to interrupt his 
 w^ork in Davis Straits (latitude 72'-* N.) on account of the multitude of 
 these insects. 
 
 Length of life of the adult mosquito. — A curious and. as yet unex- 
 plained point in regard to a phase of mosquito existence is their extra- 
 ordinary abundance at certain times upon dry prairies miles from water,- 
 which has led to the very generally accepted idea among far Western- 
 ers that all mosquitoes do not need pools of stagnant Avater in which to 
 breed, ])ut that certain of them must have some other breeding habit. 
 This supposition still appears incredil)le to the Avriter, who is much 
 more inclined to attriliute this abundance in drv reo-ions to a o-reater 
 longevity on the part of the adult mosquitoes of certain species than 
 has been proven, thus ena])ling these great swarms to live from one 
 rainy spell to another, no matter how^ widelv separated. The gravid 
 females of most insects seem to be able to live until they have oppor- 
 tunity^ for appropriate oviposition. The writer is frequently asked as 
 to the duration of the adult stage of mosquitoes, but bevond the 
 statement that although adults hibernate, living in this condition from 
 November until April or May in the latitude of Washington, he is 
 obliged to state that thev die rather quickh^ in conlinement in the 
 summer. He has had living specimens of Anopheles quadrimaculatus 
 confined in breeding jars for eight da^^s, all dying, however, at the 
 expiration of that time. Dr. Woldert has kept adults for fifteen days 
 in a wide-mouthed bottle in which was placed a small slice of banana, 
 the gauze with which the bottle w^as covered being sprinkled ever}^ 
 day. Other specimens were kept from fifty to sixty days, but this 
 was in the late fall, and many of them would probabh^ have hiber- 
 nated. Dr. ]Manson states that they ma}^ be kept for wrecks in a glass 
 vessel containing a piece of ripe banana, the banana being renewed 
 everj^ three or four days. 
 
n 
 
 Lit' Jus/urij nf' iiiostjuitiHs in i/« IK /'III. Ill *,'"('iH'l*al U'l'IUs lh<» hiologV 
 of till' Curniilu' -tlio fjiinily to which the tnu' iM(>s<|uitoes In'lontr — 
 may luiflly Im' sninnuHl iij). All j^n'iicral >tat«'iin'iit> luTctoforo have 
 Imm'ii l»asr(l ujmmi tlir life history of oiu' or two sju'cics of thi* ji'iMuis 
 Ciih'x. \v{ it is ccitaiii that such remarks will not only not hold for 
 the whoh' family, hut that, except in a general way. tlicy will not hold 
 foi- all the species of ( 'iih'X. So fa?- as is detinitely known, the larva* 
 of all m<)S(juit(Hvs ar«' aqnati<'. althouji'h they an' tiin' air hreatht'rs; 
 that i- (() say. tlicy iiiii>t <'<>mc to the surface {\i the water to hreathe. 
 Tiny ar;- ra})i(l liiceders and })ass the pupal condition also in water, 
 hut tloatin<^- normally at the surface. They pa>s throujrh several «^en- 
 erations in tin* <ourse of a year and hihernate as adults. Hihernatint( 
 iiios(juitoes juay fieijuenlly ))e found durini,' the winter months in 
 harns and in the cellai's and cold «:arrets of houses. Dr. W. S. 
 Thayer, of Haltimore. informs the wi-iter that he found Antfph^^lex 
 rrnciiins and .1. tjinnlr/ iiKicuhifus hihernatini^ in <'norinous nund>ers in 
 harns near New Orleans, clusterin^^ umU'r the roofs and on the walls. 
 In the exti'eme Southern States many mos«|uitoes are activi' all throu»>"h 
 the winter, and moscjuito hars ar«' almost as necessary at Christnuis 
 time as <lurin*:- the sununer. 
 
 yuitil fif adult innHij^ii'itiHs. — It is a well-known fact that the adult 
 mal(* mosijuito does not necessarily take nourishment and that the 
 adult female does not necessarily rely on the blood of warm-hlooded 
 animals. The mouth parts of the male are so diti'erent from those of 
 the female that it is probable that if it feeds at all it obtains its 
 food in a quite ditienMit manner from the* female. They are often 
 observed sipping- at drops of water, and in one instance a fondness 
 for molasses has been recorded. 
 
 Tln' writer has already placed on record the instance in which his 
 eolleatrue, Mr. E. A. Schwarz, observed a male moscjuito si})ping beer, 
 but \\w most inteii'stini^ instance of alcoholism of the male mosquito 
 which has come to his notice was described in a letter icceived last 
 sprinu- from l)r. St. (b^or^-e Gray, of Castries, St. Lucia, British 
 West Indies. I)r. (iray wrote: 
 
 "The inales, especially (\ pipimtif are very f(»n(l <»1 wine, ami almost every day I 
 can cat<h one (»r two — always males — on the neck of the cltH-anter or in a wineglass 
 that hiLs just l>eeii used. I jmt a few mosquitoes under a 1k?11 jar one day in order to 
 watch them. I j»ut a single drop of port wine under the jar, iis I had heard that 
 mMS(|uitoes could 1k' k«'j>t alive for a lung tinje on wine. When I went to look at 
 them a few luairs later I found them all api>aivntly dea«l, so I put them in a <lry 
 iMjttle, intending to i>in them later. When I went to pin them shortly afterwanls 
 they were all staggering aliout in the most ridiculous manner — they weiv drunk!" 
 
 The female moscjuitoes ar«' normally without nmch doubt plant 
 feeders. Why they should draw blood at all is a (|uestion which has 
 not been sohed. It lias l»een >urmised that a >ui)ply <d' hiirhly nutri- 
 
18 
 
 tivo tluid is nr/oss;iiT tor tlic foiination of the cj^'^r^, Imt lliis sn])|)()si- 
 tioii is at once (Miiphatically iiouativcd by tiio fact that mosfjiiitocs 
 a})Oiuul in reg-ions into which wanii-hjoodcd animals ncvci- ])cnctrato. 
 The statement which the writiM- has (Mscwlicic made, tliat not one in a 
 million ever oots the opportunity to taste tlic blood of a warm-blooded 
 animal, is unipiestionably an un(lerestimat(\ There are in this counti-y 
 enormous tracts of marshy hind into whidi warm-])lo()(l('(l animals 
 never tind their way and in which mos(piitoes are breedino- in count- 
 less numbers, and when we ovt within the Arctic Circle^ and other 
 uninhabit(Ml regions the point is emphasized. Scattered through the 
 seven volumes of Insect Life are records of the observation of the 
 vegetarian habit, one writer stating that he has seen mosquitoes with 
 their beaks inserted in boiled potatoes and another that he has seen 
 waternudon rinds with man}' mosquitoes settled upon them busily 
 engaged in sucking the juice. That they may and occasionally do 
 feed upon other than warm-blooded animals, however, is evidenced 
 by an observation by the late Dr. IT. A. Hagen, who mentions taking 
 a species of mosquito in the Northwest which was engaged in feeding 
 upon the chrysalis of a butterfly , while there are several instances on 
 record where they have been observed puncturing the heads of young 
 fish and killing them. 
 
 IIov) few v:lll rnosquitocs JJy? — The cpiestion is often asked: "How 
 far will mosquitoes fly from their breeding places, or how far can the}^ 
 be driven l)v the wind i '' In some instances this becomes a matter of 
 practical importance, since, if mosquitoes fly great distances, extermi- 
 native work on the lireeding places near a house or comnumity will be 
 of comparatively slight avail. There exists on this point a difl'erence 
 of opinion. In a discussion at the meeting of the Association of Eco- 
 nomic Entomologists at Boston, in August, 1808, Dr. John B. Smith 
 stated, in referring to the possibility of mosqidtoes l)eing carried In^ 
 strong winds to considerable distances, that he had noticed that they 
 would not rise or take flight when a brisk breeze was blowing, and 
 that even a comparative!}" slight breeze will keep them from upper 
 stories in houses. He, therefore, doubted the wide distribution of 
 mosquitoes by high winds. Dr. H. T. ^ernald stated that at Cold 
 Spring Harbor, Long Island, with a north breeze there are no mos- 
 quitoes. With a south breeze, on the other hand, they are often very 
 troublesome, especially after a prolonged gentle wind of five or more 
 hours' duration. There are no pools in the center of the island, and 
 the mosquitoes are supposed to have been carried from the south shore, 
 a distance of some 15 miles. This question became a very practical 
 one to the members of the Richmond County Country Club on Staten 
 Island, in their operations against the breeding places of mosquitoes 
 on the island, since, if a new supply could be carried over hy the 
 winds from the New Jersey coast near by, a large portion of their 
 
14 
 
 labor would be wasted. Mr. ^\'. ( '. Korr, the orij^iiiator of the mos- 
 quito work at that placo. and an cxcclhMit ohscM'vcr. is dcc-idodly of 
 the opinion that uioscjuitocs aro not })routrht over from New Jersey. 
 
 Ahnost cNcrvoin' must liave noticed the hal)it of mos(|uitoes of 
 elin»rintr to luanches of trees ajid j^i-jisses durinir a hii^-h wind, swarni- 
 in»r out in tliLdit as the wind subsides. ])ut tliere must he instances 
 when they aic LTcatly aided in spreadinj^ by such gentle winds as 
 those mentioned a))ove by Dr. Fernald. 
 
 In this connection an o})servation made Ijv Mr. \i. M. Keese in 
 Baltimore is siifniticant. He found that by ti-eatinjr the privy vault 
 in his l>ackyai(l with kerosene, the su])})ly of moscjuitoes to the house 
 was LTeatly re(hiced. althou<jjh there were many otlier brecdinjr places 
 ordy a litth' farther removed. 
 
 Another siifnificant instance was mentioned )>y Prof. H«M*bert 
 ()s))orn at th(^ Boston meeting of the Association of Economic Ento- 
 mologists. He said that in dry seasons the small pools w ithin a quar- 
 tei- to a half a mile fi'om the college })uildings at Ames, Iowa, dry up 
 and tlie mosquitoes disappear, in spite of the fact that within about a 
 mile there are large pools which never lu'come dry. 
 
 On this point Mrs. (\ 1^. Aaron writes very sensibly as follows 
 (Dragon Flies 7'.s'. Mostpiitoes — The Lam))orn Essays, Aj^ph^ton & Co., 
 1.S90. pp. 8.5-86): 
 
 Tlu' inigratiun of mosquitoes h'dfi ])een tlie source of imuli luisiipurehengioii (m the 
 ])art of the i>ul)lir. The idea jirevak'nt at <mr seasi(U' resorts that a hind breeze ]»rinp< 
 the swarms of mos(}uitoes fmm far inland is based on the sui»positioii that it is capable 
 of l<)nj;-siistaine(l flijrht and a certain amount of hattHn*;a<rainst the win<l. This is an 
 error. Mos<piitoes are frail of wing; alijzht puff of breath will ilbL-^trate this by hurling 
 the helpless creature away, and it will not venture on the wing again for 8ome time after 
 finding a safe harbor. The prevalence of niosquitoe.s during a land ])reeze is easily 
 explained. It is usually only during the lulls in the wind at such times that Culex can 
 fly. Generally on ourcoast a sea breeze means astiff breeze, and during the.seeven the 
 Odonata, and often the ro])ust and ventursome Tabanid;e, will be f(»un(l hovering on 
 the leeward side of the houses, sand dunes, and thick foliage. In the meadows south 
 of Atlantic City, N. J., large swarms of Culex are sheltered in the dense gra.<s or 
 wind-battered tree tops on the off side of the sand dunes. Here, in common with all 
 localities so exposed to searching w ind, the trees and hirge bushes are much stunted 
 in growth and battered down to ^ flat top and common level by the wind. In these 
 matted branches, dense with the close-clustered foliage, the mos(]uitoes may be dis- 
 covered in such numbers as to bring despair to the heart of the student who is plot- 
 ting their final extermination. While the strong ])reezes la.«t Culex will stick close 
 t4) the.>^' friendly shelters, though a clustiT of houses may be but a few rods off, filUnl 
 with unsusix'cting mortals who imagine their tormentors :\rc far inland over the salt 
 mea<lows. But if the wind dies down, as it usually does when veering, out come 
 swarms upon swarms of the females intent upon satisfying their depraved taste for 
 blood. This explains why they appear on the field of action almost immediately 
 after the cessiition in the strong breeze; on the supposition that they were blown far 
 inland, this sudden reappearance would l)e unaccountable. 
 
 Can^uHjc of ijiosfjuitoes hy ranimty traim. — The State of New^ Jersey 
 has an unfortunate reputation in connection with mosquitoes. While 
 
15 
 
 it is uiKl()ul)t(Hlly true that inosciuitocs an* Ncrv abimdaiit in most |)ai-ts 
 of tho State, tliat fact doos not iiicaii to the w i-itrr tliat in the (greater 
 part of the State there are any more hreedino- spaces or that moscpd- 
 toes are an}^ more prolilie within the State borders thjm elsewhere. 
 It does, however, seem to him that ther(^ is constant carriaj^-e irdand 
 from the marshy seacoast of ver}' many mosquitoes, but ])y this \\v. 
 does not int(Mid to convey the idea that they are carried by wind or 
 that they tly to any great distance inhmd. There arc other means of 
 conveyance, and of these railway trains seem to be very important. 
 All through the summer evenings many trains are started inland from 
 Weehawken, Hoboken, Jersey City, South Amboy, Long Branch, 
 Atlantic City, Ocean City, and Cape May, N. ,]. Many of the cars, as 
 the writer knows from experience, contain mosquitoes by the hun- 
 dreds. In this way unlimited quantities of mosquitoes are carried 
 unlimited distances, and, emerging from the cars, will start to breed 
 even in localities where mosquitoes are ordinarily rare, or would be 
 rare under ordinary conditions. In this wa}^ even mountain resorts 
 will get their supply of lowland mosquitoes, and with the improve- 
 ment of railway service and the increase in number of through cars 
 the danger is constantly increasing. The writer knows of one instance 
 in the Catskill Mountains in New York where the infestation of a pre- 
 viousl}^ uninfested place (;ould have been brought about in no other 
 Avay. Through parlor and through baggage cars now run from Jersey 
 City and Weehawken into the heart of the Catskills and through trains 
 from Boston into the White Mountains. 
 
 In the same way through cars run from Baltimore into the Blue 
 Ridge, and thus a constant source of supply may be, and undoubtedly 
 is, kept up. 
 
 How long can the larvoi live out of water? -^Kt the meeting of the 
 Association of Economic Entomologists above referred to. Dr. Smith 
 asked if it were possible for mosquitoes to breed in mud, and sug- 
 gested that there was no reason to believe that the actual presence of 
 water was necessary for all mosquito species. The writer has seen a 
 statement from some Californian, which he is unable to place at the 
 present time, to the effect that there is a prevalent belief in some parts 
 of the United States that when a surface pool dries up half -grown 
 larvae may exist in the drying mud for some time, reviving with a 
 fresh rain. Mr. C. x\. Sperry, of Chicago, wrote us early in 1899 
 and advanced the same theory. He said that experiments made in 
 small vessels had always been ver}" unsatisfactory to him, and that he 
 abandoned that method and sought the natural breeding places for 
 investigation and experiment. Earl}' in July he found a wet-weather 
 pond with mosquito larvae in it, the pond being nearly dry. In a few 
 days the water was all gone. He examined closel}^ and discovered no 
 dead larvae. In about a week it rained, and as soon as the rain 
 
>t(»|i|M(| lie went to llir i)l:u»' and found tlh' mosquito lar\a':iil throuji^h 
 tlu" watrr as li\rly us cvtT. and they iK'j^jin to issiio- jis adults about :i 
 \v<M'k l'i-om that tiiuc Aj^siin he discoNc^n'd ji place whciv. the water 
 had ncaily diicd up. and hundreds of inoscpiito hir\ii' were seen }»y 
 hiiii on the \v««t »^round. Three days hit<'r it raiiiod, and ho found the 
 laiNJi' in the watei'us Ii\<dy as e\-er. In the same way Mr. Benjamin 
 S. I^l^<•hall. of Newlield. N. d.. has communieated to us o})servations 
 of iii>^ own whi<h indicate t<> tiiin a possibility that mosciuitoes umy 
 lueed in iiiass o|- iuoi<t eailh. 
 
 lv\p«'i-iments made at lhi> ollice on a small scale in j^hiss vessels 
 lia\e >hown that the lai\a' <d' ( "ulex will exist for some little time in 
 wet nmd, atui s<»me of them will succi'ssfully tiansform after water 
 ha> heen added. In no case, however, were we ahle to revive larva* 
 in mu<l fi-om which the water had h<'en drawn off for more than forty- 
 eieht hours, and aftei- twenty-four houis ordy a small proportion of 
 the lai"\ a' rexived. An interest iii}^' pool has heen under ohservation 
 (hiririL: lhe])re>ent month. The pool containinl a surface area of about 
 L'l ><|uai-e f(M't. and was fed entii'tdy ])y rain water and surface drain- 
 ai:'e. reaching- a depth when full of about 1 foot. All through the sum- 
 mer tliis ])o()l is w(dl st()cke(l with mos(juito lar\ie. After a somewhat 
 Ioul:' <lrouL:ht tlie watei* was observed on ffuly IS to have eva})orat<Hl 
 almost entirely, a small puddle in the center of the cavity, containing 
 oidy .") or 4 cubic inches of water, remaining-. It was dark in color, 
 owinji' to the drainage from a manure pile near by. and to the casual 
 o})se!M'r showed no signs of life. The water in this little puddle was 
 vvvy shallow. On di])pin<^ in a c()tlee strainer, however, it was found 
 to be literally massed with nearly full-orown mosquito larv;v, many 
 hundrc'ds of which htid been lirouoht together into this restricted 
 place. The (IryinL! (oiUimied until there was almost no water left. 
 ()!i the nieht of the '3H\\ came a heavy rain, followed with a still 
 hea\ i«'r one on the morning of the '2'M. On the :^.'>d the pool was 
 found to be entirely fidl of watei" and to contain its usual stock of 
 mos(piito larva'. 
 
 This may }>e safely said to indicate the usual habit of mosquito 
 lar\a' in e\aporating ])ools. As the water gradually recedes toward 
 the deepest portion (d' the (wcavation, the lar\a' reccMle with it, con- 
 centrating thems(dve< at the deepcv^t point, i. e.. at the ])oint where 
 the moisture remains longest. Knowing as we do. then, that even 
 in the a)>sence of any free wat«M- tlu^ laiva' will remain ali\c in moist 
 mud for from twenty-four to forty-eight hours, it is e\ ident that 
 such a |)o(d as tin' one dcvscribed gradually drying would give the 
 api)earance of liaxing l)een pi-actically .dried u}) for sonic days before 
 the last <ul>ic inch of free water has entirely disappt^ared. The con- 
 centration of many lar\a' at this point in the manner which has been 
 descrilx'd could not fail to give rise to the )>elief that mosipiito larv^ai 
 
17 
 
 will exist in the absence of free water for a iniieh lon<^er period than 
 is reall}^ the ease. In the opinion of the writer, where th(i nuid dries 
 up entirely the nioscpiito larva* are necessarily killed, but that they 
 may exist in very wet nuid for a longer or shorter time is true. 
 
 An interesting observation ))earinj^- upon this i)oint has ])een made 
 by Dr. St. George Gray, of Castries, St. Liuda, Rritisli AVest Indies, 
 and reported in the Journal of Tropieal Medicine, London, May 15, 
 1900. He says that on Februarv 7, 1900, he examined a spot where he 
 had obtained larvte of Anopheles a few months before. The pool had. 
 ])cen dry for three weeks, hardly any rain having fallen during that 
 time. The surface of the mud at the bottom was cracked and dry, 
 although soft enough under the crust. He put the mud into a clean 
 pickle bottle and put about 3 inches of filtered water over it, but there 
 was no result. He also took some grass from the sides of the pool and 
 put that grass into another pickle bottle, adding 3 inches of filtered 
 water. On the following morning he found a few minute larvae 
 wriggling about in this bottle. These rapidly grew in size, and he 
 soon had a half dozen healthy looking larvae in his bottle. On the 21st, 
 a fortnight after he had taken the grass from the sides of the pool, he 
 reared the imago of Culex tceniatus. From this observation he argues 
 that some species of Culex, at any rate, do not always lay their eggs 
 on the surface of the water, but where they will be washed into the 
 pool by the first heavy rain. Other similar experiments were failures. 
 This record is a very interesting one, but, like all isolated observations, 
 needs verification.^ It may here be mentioned that Drs. J. W. W. 
 Stephens and S. E,. Christophers, in their article on ''The distribution 
 of Anopheles in Sierra Leone," published in the reports of the malarial 
 committee to the Royal Society (London, July 6, 1900), stated that 
 they w^ere unable to hatch the eggs of Anopheles after desiccation on 
 blotting paper for more than forty-eight hours, although they hatched 
 after twenty-four and forty-eight hours' drying, respectively. 
 
 The nuniber of species of mosquitoes. — As regards the different kinds 
 of mosquitoes, about 250 species are known, of which only about 30 
 have been found in the United States. These are divided into 5 differ- 
 ent genera, each of which will receive consideration in the following 
 pages. Of the malarial genus Anopheles, Mr. F. V. Theobald writes 
 us there are 27 species in the British Museum collection. 
 
 MOSQUITOES AND MALARIA. 
 
 This is not the place to discuss at length the history of the discover- 
 ies which have brought about the very perfect proof that mosquitoes 
 may and do transfer the malaria germ from a malaria patient and 
 
 ^Dr. Walter Reed, U. S. A., tells me that Dr. Lazear has just made a similar 
 observation in Cuba. 
 
 3949^—2 
 
18 
 
 deposit ii ill tlir hlood ot a hcaltliy i)er.son. Those interested are 
 li't'ciiM'd lo llir :i(liiiii-:i})l«» })aj)<'r entitled ''On the role of insects, 
 Aiachnids and M\ liapods, as i-arriers in the spread of Imeterial and 
 j)arasitie dis<»ases <»!' man and animals; a critieal and historical study," 
 })y (ie()rw-(> II. Xuttall, M. D., Ph. D.. puldished in Volume VIII (►f 
 the Johns Hopkins Hos|)ital Ue})oits. and to latei- American sununaries, 
 amonjr whi<li may Ix- mentioned that hy I)|-. W. N. Berkeley in the 
 New York Medical Record for l)ecemi>er i>:), 1S1»0, ])y Dr. Alhert 
 Woldert in the Jouifial of the American Medical Association for Fid)- 
 ruary 1<». I'.mmi.' and l»y Dr. William Hritt lUirns in the Memphis Medi- 
 cal Monthly for March. \\H){). One of the most thorou*,^! of the recent 
 reviews will )>e found in Xaturt* for Mai'ch '2\K l'.*0(», paj^es 522-5:^7, 
 entitled ''Malaiia and moscpiitoes," a lecture delivered at the Royal 
 Institution of (Jreat Britain on March '2, ])y Maj. Ronald Ross, D. P. H., 
 M. R. ('. S.. lecturer in tropical medicme, University Collei^e, Liver- 
 pool, himsidf OIK* of the Avorkers whose results contributed most 
 materially to the establishment of detinite proof. Another recent 
 account will be found in the Popular Science Monthly for ,Iuly, lUOO, 
 l)y Dr. Patrick Manson, entitled *' Malaria and the malarial parasite." 
 It should be stated here, howeviM'. that only the mos<juitoes of the 
 genus Anopheles have ])een found to contain the human blood para- 
 sites, alth()Utj;h it (lo(\^ not appear from the published accounts which 
 have met the writer's eye that any other genera than Anopheles and 
 Culex have been studied in this connection. 
 
 The Italian observers have found that all three species of the human 
 HaMuamoebida^ are cultivable in Afioj)/te/fS cJaru/rr and not only in 
 this })ut in other Italian species of Anopheles, while the}^ together 
 with Ross and other observers, have failed to cultivate the parasites 
 in ( 'ulex. The same fact is upheld by the extended observations made 
 in AVest Africa and in this country so far as observations have been 
 made as yet. The writer, however, wishes to emphasize the point 
 which he made before the Ameiican Medical Association on June 6, 
 IJHiO. that American physicians, (vspecially those in the Southern States, 
 should not d(day the invv'stigation of the very large moscpiitoes of the 
 genus Psor()i)hora and Megarhinus f. om the malarial standpoint. Both 
 of these genera ha\'e been ligured and descrilied in succeeding pages. 
 
 SYNOPTIC TABLES OF THE NORTH AMERICAN MOSQUITOES. 
 
 In order to iMiable the ready determination of our different mos- 
 (juitoes the writer ])ublished in Circular -iO, second series, of this office, 
 in Fehruar}' of the present year, a series of tables, drawn up at his 
 request by Mr. D. W. Ccxjuillett, of the office force, comprising (1) a 
 
 ^ Dr. Woldert's article contains a good account of the internal anatomy of mosqui- 
 toes and describes his methods of dissection. 
 
10 
 
 S3'nopsis of the Hvo j4"iM'*''''* iiiidci- w liicli Ihc I(»nu ))«';ik(Ml. hlocxl-suck 
 iiig spei'ios known to occiii- in Noilli America wcic dixidcd; (2) ji 
 synoptic considci-ation of the sp(H'ics of (he ncniis Cidcx. divided into 
 (a) ta])le of the iHM'oiiiii/cd species, s])C(inieiis of which occur in the 
 National Miiseuni coUection, and (/>) an account of the unrecognized 
 species, whicli are known oidy from tlie literature; {?>) a synoptic con- 
 sideration of tlu> s])ecies of the o-enus Anopheles. (li\ided into (//) 
 recoo-nized forms, and (/») unrcH'ooni/ed forms; (4) a ))rief description 
 of the only valid known species of the o(muis Psorophora; (;">) a synop- 
 tic table of the three known species of the genus Megarhinus; and (()) 
 a svnoptic consideration of the two known species of the genus Aedes. 
 Mr. Coquillett's tables are here reprinted with slight changes: 
 
 I. — Generic Synotsis. 
 
 The following table contains all tlie genera of the long-beake<l mosquitoes known 
 to occur in North America. The males are readily recognized ])y the antennte being 
 densely covered with long hairs; in the females the hairs of the antenna? are short 
 and very sparse: 
 
 1. Palpi in the male at least nearly as long as the proboscis; in the female less than 
 
 one-half as long : 2. 
 
 Palpi in both sexes at least almost as long as the proboscis Anopheles. 
 
 Palpi in both sexes less than one half as long as the proboscis Aedes. 
 
 2. Proboscis straight or nearly so, colors of body brown and yellowish 3. 
 
 Proboscis strongly curving downward toward the tip, colors bluish or greenish. 
 
 .Megarhinus. 
 
 3. Legs bearing many nearly erect scales Psorophora. 
 
 Legs destitute of such scales Culex. 
 
 JI.— (texcs ('ulex. 
 
 («) KECOGXiZEI) SPECIES. 
 
 Malex. 
 
 1. Front tarsal claws bearing a distinct tooth ii(>ar the middle of the underside of 
 
 each 3. 
 
 Front tarsal claws bearing two teeth on the underside of one claw, and one on 
 underside of the other, proboscis destitute of a whitish band near the mid- 
 dle 2. 
 
 Front tarsal claws with one tooth on underside of one of the claws, none on the 
 other, bases of tarsal joints white, proboscis destitute of a whitish band near 
 the middle fasciatus Fabr. 
 
 2. Tarsi distinctly white at bases of the joints exritans Walk. 
 
 Tarsi not white at bases of the joints (Wisobrinns Desv. 
 
 3. Proboscis destitute of a whitish ring near the middle 4. 
 
 Proboscis with such a ring, ends of tarsal joints white tarsalis Coq. 
 
 4. Bases of tarsal joints not white 5. 
 
 Bases of tarsal joints white stimulans Walk. 
 
 5. Petiole of submarginal cell less than one-third of the length of that cell. 
 
 pungens Wied. 
 Petiole of submarginal cell at least one-half of the length of that cell. 
 
 impiger Walk. 
 Females. 
 
 1. Front tarsal claws bearing a distinct tooth near middle of iindersideof each.. 2. 
 Front tarsal claws destitute of teeth , 7. 
 
20 
 
 2. l*n>lM)(*cis (IcHtimto «»f a white riii>; lu-ar the middle 3. 
 
 Pruho.'ii-iH iiiarketl with .^ach a rinj:, ha.<<'S of tarsal joints white. 
 
 l:niiorln/nehits Wied. 
 
 'A. liiUH^H of tarsal joints distinctly white 4. 
 
 Iias«'s of tarsal joints never white 5. 
 
 A. Mrsonotmn inarkrd with fonr stripes of silvery scales fcusciatua Fabr. 
 
 Mesonotuni (h'stitiite of such strijK's: 
 
 Kiftii joint of hind tarsi white ixnlfffus Wit'tl. 
 
 Fifth joint, except its extreme base, dark brown ftimnltniA Walk. 
 
 T). I^ist two joints of hind tarsi never white (i. 
 
 l^ist two joints of hind tarsi snow white pontiaiiuH Wied. 
 
 (». Alwlt.nn'n marked witii a cross l)and of whitish scales at l^ase of each segment. 
 
 un}n(j(r Walk. 
 AlMlomcn nev»'r marke<l in this manner, but with a cluster of whitish scules at 
 
 front anodes of some of the sej^Miients irixcnatris Say. 
 
 7. Tidboscis marked with a distinct whitish rin^ near the middle, tai-si white at 
 
 sutures of the joints 8. 
 
 Proboscis <lestitute of a whitish rin^ near the nnddle 9. 
 
 S. Tarsal joints white at bases only peiiurhdns Walk.' 
 
 Tarsal joints white at both ends tarmllx Coq. 
 
 \K Tarsi white at bases of joint« 10. 
 
 Tarsi never white at bases of the joints 12. 
 
 10. Mesonotum never marked with stripes (»f silvery scales 11. 
 
 Mesonotum marke<l with four striju's of silvery scales, first tarsal joint never 
 
 marked with a whitish rin«; near the middle sifjui/er Coq. 
 
 1 1. First tarsal joint niarke<l with a whitish rin^' near middle of each. 
 
 rxcTuriariH W^alk. 
 
 Fii-st tarsal joint destitute of such a rin^ rrriUma Walk. 
 
 IL*. Petiole of submar^inal cell less than one-third of the len<:tli of that cell. 
 
 jiungenx Wie<l. 
 Petiole of submarginal cell at least almost one-half of the length of that cell. 
 
 consobrinus Desv. 
 
 {})) rNKKCO(iNlZKI) Sl'KClHX. 
 
 <in)iiil(tfns Schrank. This Furopean species was credited to our fauna by Osten 
 Sacken. The description a<rrees fairly wi'll with spi'cimens which I have identiHerl 
 •Afi rrcif a IIS, Walker, e.xcei)t that in the latter there is no white ring on the femora 
 toward their apices. 
 
 hosrii Desv. Proba])ly a rnb])e<l sjH'cimen of -jiiinfjnu. 
 
 iii(jrijus Zett. Black, the legs of the male <lark yellow, hairs of ])leura of female 
 gray, a band of white scales at base of each segment of her abdomen. 
 
 ndiiiliiH Desv. The description was api)arently founded on a rubbed specimen of 
 P.siiiojilioni ciliato. 
 
 (i'Kidrnis V. d. Wulp. Is probably a somewhat injured example of mtifdthriuns. 
 
 iiiridnis Thomson. Is evidently a synonym of hnpigir Walker. 
 
 hiffofi Bellanli. Accordiui: to ti:e figure and descri])tion, the bands of black scalofs 
 are at the /^a.sv.sof the abdominal segments; in the recognized sp(»cies thesi' ])an<ls are 
 always at the apices of the segments. In other resjjccts this species nmst greatly 
 resemble jniiif/riix. 
 
 ciihnisls Bigot. Apparently founded on a l)adly rublx?<l six'cimen of pnngens. 
 
 fi'dUr Desv. This name was jiroposed for the ('nli\r fiiifcldlu.s of Wiedemann, under 
 the impression that this is not the same s|)ecies as the one describe*! by Fabriiius 
 un«ler the same nanie. It seems quite certain, however, that the word "proboscis" 
 in Kabricius' <lescription was simply a lapsus for "i)alpi," and with this emendation 
 the two descriptions agree very well. 
 
 incxirtimi Bellardi. Is evidently a synonym of postimtns. 
 
 prororniis Walker. Is probably a synonym of stiiiiKhuis. In some specimens of 
 this speciis the light color at the bases* of tlie tarsal joints is very indistinct. 
 
 Urritunx Walker. Is apparently a syuonyui of punyciis. 
 
 'Mr. F. V. Theobald, after ptudying Walker's type of perlurbans, writes us that it 
 has toothed claws in the female. 
 
Our rooop:nizo(l sju'cic^- 
 svnonviMS iiidciitiMl: 
 
 >f ( 'ulcx anil t lu'ir sviiomn 
 
 l)f list('(| :is I'ollows, til 
 
 coiisohriii Ufi I )esv . 
 
 ? arini(lim(inus \. d. A\'iili> (Ano- 
 pheles). 
 
 impdtlciis Walker. 
 
 inonuttii.^ Williston. 
 
 ])in(jiiis Walker. 
 
 pnnrtor Kirhy. 
 
 ? tt'stdcnis V. (I. AN'ulp. 
 e.rcitdiu Walker. 
 
 ? (iiniit/dtiis Osteii Sacken {nee 
 'Mei.treu, etc.). 
 exmtrkdis Walker. 
 J'mriddts Vnhv. 
 
 f rater Desv. 
 
 iiiffstjiiito Desv, 
 iaeniatns Wied. 
 impiyer Walker. 
 
 implarahlllx Walker. 
 
 incident Thomson. 
 
 ? quinquefasciatus Say. 
 
 jxrliirlxniti Walker. 
 j)(},slic(ihis Wied. 
 
 ? iiiexiadiKs l>ellardi. 
 
 Ill 1 1 sit- lis Say. 
 piiiK/i'iis Wied. 
 
 ? hoscil Desv. 
 
 ? riihenxis Jii<j;()t. 
 
 ? farilans Walker. 
 ngnifer Coqiiillett. 
 stiimddiiH Walker. 
 
 ? prorocdiis Walker. 
 iaenior/it/iicliiis \\'ied. 
 
 ilaiiniosns Say. 
 
 ml/iciUm.H AV'alker. 
 tarmlis Coquillett. 
 Inseriatus Say. 
 
 III. — Genus Anopheles. 
 
 (a) KECO(iNIZEI) SPECIES. 
 
 With a yellowish white spot near three-fourths of the length of the front margin 
 of the wing; scales of last vein white, those at each end black, pundipennu Say. 
 
 Without such a spot 2. 
 
 Scales of last vein wholly black, palpi wholly black quadrimaculatus Say. 
 
 Scales of last vein white, marked with three black spots, palpi marked with while 
 at bases of last four joints crucians AVied. 
 
 (h) TTNRECOGNIZED SPECIES. 
 
 The following species which have been credited to our country have not been 
 recognized with certainty; some of them probably do not belong to the present 
 genus, while a few were evidently founded on badly rul)bed specimens in which the 
 distinctive characters were therefore wanting: 
 
 annulimamis v. d. Wulp. I strongly suspect that this does not belong to the present 
 genus; the description applies fairly well to the male of Chdex consohr'mns Desv. 
 
 ferruglnoms AVied. This author proposes this name for the species previously 
 described by Say under the name of Culex quinquefasciatus, but the descripti(^n which 
 he gives differs so decidedly from the one published by Say as to give the impression 
 that it is founded on a different species. I strongly suspect that the type of ferni- 
 ginosusis a rubbed example oi Anopheles crucians, which was described from the same 
 locality. Say's description of his Culex quinquefasciatus agrees very well with the 
 species which I have identified as Ctdex imjnger Walker. 
 
 macidipennis Meigen. I strongly suspect that this European form is identical with 
 our Anopheles quadrimaculatns Say, but this point can not be settled definitely at 
 present, owing to the lack of any iEuroi)ean specimens for comparison with ours. 
 
 nigripes Staeger. This European species should be readily re{!Ognized by its 
 unspotted wings. 
 
 a.lbimanus Wied. Differs from our other species by the snow-white apices of the 
 tarsi. 
 
 Anopheles pictus Loew is evidently a synonym of A. crucians AVied. 
 
 Our recognized species of Anopheles and their synonyms may therefore be listed 
 as follows, the synonyms indented: 
 
 crucians AVied. - pundipennis Say. 
 
 pictus Loew. hiemalis Fitch. 
 
 1 ferruginosus AVied. quadrimaculatus Say. 
 
 ? maculipennis Meigen. 
 
I \ .--« ii:\l V I'-.iiioIMlORA. 
 
 < Mil -iiiLiK -jMi M ~ 1- ... a yrllowish color, usually varicil with brown, tlie l>a>«eH ot 
 tlu' tarsiil juiiitM white. It is coiisidfiiihly larger than any uf uur other s|)eeie« of 
 yellowish or hrowii iintsi|iiitoeK: 
 
 filitittm Fahr. 
 
 fimlti'iuiis Walker. 
 till titxt IIS NN'ieW. 
 
 ? iilbitln,^ Pesv . 
 
 y. (lENlS "Mi:<iAHMINrs. 
 
 ( Mil three ^ju'iies ai»' aiiioii;j the largest in this family, and are imt kn(»wii to ueeiir 
 north ol the histriet of ( 'oliiniitia. They may he separated as fulhtus: 
 
 All tarsi marked with white ruiilius Coq. 
 
 I lind tar.-i alone marki-d w ith wliite p</ilorirewtiif Roeder. 
 
 None (if the tarsi marked with whitt . Im iiioi'rhoi(]<ifij< F'dltr. 
 
 \'l. < iK.M s AkI)1>. 
 
 *»iii iNM. ^|H^l^- o. .iiiM.i.u the smallest of our mosquitoes, an<l havt^ a jtale 
 hmwuish ground color. They may Ik- «listinguished as follows: 
 
 Thorax marked with a njedian violet hlue striiu' sapphirinuit O. S. 
 
 Thorax destitute of such a strij.e fnxrus O. S. 
 
 THI. 1U(U,<»(;^ OF CILK.X. WITH liK.MAKKS I fON S< )M K <)l" THK SPKCIES. 
 
 h is toh'iahly (('i-tiiiii th:it the life found of nil of the species of the 
 o-eiiii> (iih'x is juactirailv the sumo. They will differ more or less in 
 the cliaraeter of tlie water in wJiich they ])referahly ]>reed. and dift'er- 
 ino- in this re.^pect. they will ditfer also in some degree in their pre- 
 ferred food, which consists of all sorts of aciiiatic mieTo-orgaiiisms. 
 Down to the tiin«' when the writer puhlished his account of Cultx 
 jHimjtus^ in l^ulletin No. 4. New Series, of this otfic(», there was not 
 in any puhlished work a thoroughly satisfactory figure of a well- 
 determined species of moscpiito from the Unitx^d States, or of its 
 earlier stages. The statements (juoted in the text-hooks and maimals 
 dated })ack in general to the time of Keaiunur- more than one hun- 
 dred and fifty years ago. Reaumur's observations were made in the 
 month of May upon a species {( 'hIcv jhjh^'hs) which does not occur in 
 North America, and the observations were all made at Paris, so that 
 statements a-; to tlii' duration of the insect in any stage woidd be 
 incorrect cNcn for the same sj)ecies in a warmer or colder locality. 
 The following accoiuit of the life history of Cdh.r puiKjins (tig. 1) is 
 (|iiot»'(l from the writer's bulletin aboxe cited: 
 
 L'ifi li'isinrij i>f ('i(/r.i' j>uji(/rths.--V\\v operation of i')i)f laying was 
 not obseiAM'd, but it probably tak(\s place in the very early morning 
 lioiiis. \\\v eggs are laid in the usual boat-shaped mass, just as those 
 of r//A./'yy/y>//7/.v. as described by l^eaumur. We say boat -shai^'d mass, 
 becaus*' that is the ordinary expn^ssion. As a matter of fact, however, 
 the egg masses are of all sorts of shapes. The most common one is 
 
 ^ 
 
28 
 
 tla' ])()iiit(Hl ellipse, convex Ix'Ionn and coiieuN «« above, all llie e«^*^*s per- 
 peiulieiilar, in <> to \'^ lono'itiulinal rows, with iVoiii IJ or 1 to 4< ) eoo-.s in 
 a row. I'he mnnherot' eo-L;-s in each l>alcli \aries i'l-oni 200 to 400. As 
 seen from ahoNC tlie eii'Ll' mass is i4rav hi'owii: t'l'om helow, silverv 
 Nvliite. the latter appearanc«' heiny' due (o (hr aii" lilm. It seems 
 im})ossil)le to wel thes(» coo- masscvs. 'Phey may he j)iishe(l under 
 water, but hob up ap})arently as dry as ever. TIh^ ego- mass separates 
 rathei- reoularlv, and the eo'sis ar(^ not stuck tooether very firmlv. 
 After they have hatched the mass ^\iil disinteorato in a few days, even 
 in perfectly still Avater. 
 
 The individual ejiiis are o.T mm. in lenoth and 0.16mm. in diameter 
 at the base. They are slender, broader and blunt at bottom, slenderer 
 and somewhat pointed at tip. The tip is always dark grayish brown in 
 
 Fig. 1. — C'ulex panyeas: Egg mass, with euglarged eggs at left and young larvae below — enlarged 
 
 (original) . 
 
 color, while the rest of the egg is dirty white. Repeated observations 
 ■show that the eggs hatch, under advantageous conditions, certainly 
 as soon as sixteen hours. Water buckets containing no Qgg masses, 
 placed out at night, were found to contain Qgg masses at 8 o'clock in 
 the morning, which, as above stated, were probably laid in the early 
 morning, before daylight. These eggs, the third week in May, began 
 to hatch quite regularly at 2 o'clock in the afternoon of the same da}^ 
 on Avarm days. In cooler weather they sometimes remained unhatched 
 until the second day. If we apply the evidence of European observers 
 to this species, the period of the ^gg state may be under twelve hours; 
 but there is a possibilit}- that they are laid earlier in the night, which 
 accounts for the fact that sixteen hours is the shortest period which we 
 can definitely mention. 
 
24 
 
 Tlu' hirvji' issue fioiii tlir undt'isich* of the og^ mjissos. siiid are 
 extreiiu'ly ju-tivr at iMrth. AVhcii lirst olhserved it is oasy to fall into 
 an error n'trardinir the lent^th of time which they can remain under 
 water, or i-ather without coming U> i\w surface to breathe, since, in 
 strivinij;- to come to thi' surface for air, many of them will strike the 
 undei*sid*' of the egg mass and remain there for many minntes. It is 
 altogetlier likely, however, that they get air at this point through the 
 ej^j^s or through the air film l>v which the Oirir niass is surrounded, and 
 that they are as readily drowned hy contiruions inmn'ision as are the 
 older ones, as will )>c shown latei-. 
 
 One of th(^ first peculiarities whicii stiikes one on oriserving these 
 ncNsly-hatclird l;ir\a' under thr lens is tliat tin- tufts of filaments which 
 aie conspicuous at th«' mouth arc in a)»so]utcly <'onstaiit \ i))ration. This 
 j)eculiarity. and the wriggling of the lar\a' through the water, and 
 
 M ' 
 
 I 
 
 ' iikx piinycns: Ilead of larva from helow at k'ft; saiiu* fnnn a]M)\«.» at rifjht— greatly enlarged 
 
 (original"!. 
 
 their great activity, render thcin interesting objects of study. In gen- 
 eral the larva', passing through :4)j)arently three different stages, reach 
 maturity and transform to pupa* in a minimum of seven days. When 
 nearly full grown, their movements were studied with more care, as 
 they were casitM' to o])serve than when newly hatched. At this time 
 the larva remains near the surface of the water, with its respiratory 
 siphon at the exact surface and its mouth filaments in constant vil)ra- 
 tion, directing food into the mouth cavity. Occasionally thi^ larva 
 descends to the ))ottom, l)ut, though repeatedly timed, a healthy indi- 
 vidual was ne\ cr seen to remain voluntarily below the surface more 
 than a minut(\ Tn ascending it comes up with an eti'ort, with a series 
 of jeiks and wrigglings with its tail. It descends without eti'ort, Imt 
 ascends with difficulty: in oth(M- words, its specific gravity seems to Ije 
 greater than liiat of tlu' watei-. As soon, however, as the respiratory 
 
25 
 
 siphon vciU'lu^s tho siirfjico, frcsli air flows iiilo its trjichcu', juul the, pliys- 
 ical prop(»rti(\s of tlio so-calliul surface iiliii of the Avatcr assist it in 
 inaintiiining its position. 
 
 The respiratory tii))e takes its origin from the tip of the eighth ab- 
 dominal seo-meiit, and the very larye trachea* can ))e seen extending to 
 its extremity, Avhere they have a double oritice. The nintli segment of 
 th(» abdomcMi is armed at the tip with four flaps and six liaii's, as shown 
 in lig. 8. These flaps ar(* gill-liki^ in appearance, though they are prol)- 
 ably simply locomotory in function. With so remarkably dcn^elopedan 
 apparatus for dii-(M't air breathing there is no necessity for gill struct- 
 ures. Haschke * and Hurst'- consider that tin* larva breathes both b}^ 
 the anus and by these gill flaps, as well as by the large tracheae which 
 open at the tip of the respirator}^ tube. Kaschke considers that these 
 tracheae are so unnecessaril}^ large that they possess a hydrostatic 
 function. The writer is inclined to believe that the gill flaps may be 
 functional as branchial structures in the young larva, but that they 
 largely lose this ofiice in later life. 
 
 After seven or eight da^-s, at a minimum, as just stated, the larva 
 transforms to pupa. The pupa, as has been repeatedly pointed out 
 with other species, differs most pronouncedly from the larva in the 
 great swelling of the thoracic segments. In this stage the insect is 
 lighter than w'ater. It remains motionless at the surface, and when 
 disturbed does not sink without effort, as does the larva, but is onl}^ 
 able to descend by a violent muscular action. It wriggles and swims 
 as actively as does the larva, and soon reaches the bottom of the jar 
 or breeding place. As soon as it ceases to exert itself, however, it 
 floats gradually up to the surface of the water again. The fact, how- 
 ever, that the larva, after it is once below^ the surface of the w^ater, sinks 
 rather than rises, accounts for the death of many individuals. If they 
 become sick or weak, or for any reason are unable to exert sufficient 
 muscular force to wriggle to the surface at frequent intervals, they will 
 actually drown, and the writer has seen many of them die in this v^ay. 
 It seems almost like a contradiction in terms to speak of an aquatic 
 insect drowning, but this is a frequent cause of mortality among wrig- 
 glers. This fact also explains the efficacy of the remedial treatment 
 w hich causes the surface of the water to become covered with a film of 
 oil of any kind. Aside from the actual insecticide effect of the oil, the 
 larvae drown from not being able to reach the air. The sti'ucture of the 
 pupa differs in no material respect from that of corresponding stages 
 of European species, as so admirably figured and described by the older 
 writers, notably Reaumur and Swammerdam^ and needs no description 
 
 ^Raschke, Die Larve von Culex nemorosus, Berlin, 1887. 
 2 Hurst, the Pupal Stage of Culex, Manchester, 1890. 
 
 ^Even Bonanni, in 1691, gave very fair figures of the larva and pupa of a European 
 species. Micrographia Curiosa, Rome, MDCXCI, Pars. II, Tab. I. 
 
^>c, 
 
 III \ H-NN <»l llirraM willi wllirli liic ii^ui»> ;i( (« »iii) >:iii \ i ii<;^ llii> :illi 
 
 lm\<' Im'cii draw II. Tln' air tuln's mo lontroi- optn at llir anal end of the 
 ))o(lv, hut tlir<»iiiili two t!'iiiiip('t-sha}H'(l sch'rit4's on tin* thorax, from 
 wliiih it roiihs that tlu' ])iipa iM'inalns uprjirht at thf surfac*', iiistciicl 
 of w ith the ht jul (h»u ii\\ar(l. I'hrrc is a \rr\ appariMil oliject in this 
 rr\ri-^al mT the p(»^ition of the Imkiv, siiR't*. tht' adult ins(»rt issues from 
 th«' thorax and immmI- th«' tloatiiiL'' >kin to sup])ort it^tdf whih' its wings 
 art' <'Xpandiiitj-. 
 
 In LjriM'ral. thr adult ins«M*ts issu«' from the pupM- that art' two days 
 
 
 Fi«i. :i. — Cult X till iKjt lis: Fiiil-giDwu larva at Ifft, |>u|ja al fIkIiI — cularKt'd (itrig^inal). 
 
 old. This iii\('s what is ])rohai>ly the mininiuin oiMU'ration for this 
 species as t<ii (hiys, namely, sixteen to twenty-four hours for the egg, 
 seven days for the larva, and two days foi- tiie ])upa. The individuals 
 emerging on the lirst day were invariably males. On the second day 
 the great majority w ere males, l>ut there were also a few females. The 
 ]ir(^})onderan('«' of males continued to hold for thriM^ days; later the 
 females wci-e in the majority. In <-ontinement the maley died quickly; 
 se\«ral li\ cd for four days. l)ut none for more than that period. The 
 femalo. however. li\ed for a much longeitime. Some were kept alive 
 
I 
 
 27 
 
 without food, ill :i conliiuMl spacc^ of not more than 4 iiiclics (h'cp l)y 6 
 across, for three AV(M»ks. lint one cii^* mass was (l(»]){)sil('(l in conlinc- 
 nuMit. This v,as(l('[)()sil(Ml on tiir nioriiino- of June )I0 hy a tVniaic w hich 
 issued from the pii[)a flune '21. No furtiier ohser\atioiis wen^ made 
 upon the time elapsino- ])etween the emerocnee of th«^ fennde and the 
 hiyinvj' of (he (\Lt<:s, hut in no ease. j)roha))ly. does it exceed a lew daNS. 
 The h'niith of time which (da|)ses for a i^"enei"ation, wliich we have 
 just mentioiuHl, is almost inch^tinitely enlaro-ed if the weather he cool. 
 As a matter of fact, a h)no- .spell of cool weather followed the issuing 
 
 Fig. 4. — Culex pungena : Female above, male below — enlarged (original). 
 
 of the adults just mentioned. Larvae were watched for twenty days, 
 during which time they did not reach full growth. 
 
 The extreme shortness of this June o-eneration is sio-nificant. It 
 accounts for the fact that swarms of mosquitoes may develop upon 
 occasion in surface pools of rain water, which may dry up entireh^ in 
 the course of two weeks, or in a chance bucket of water left undis- 
 turbed for that length of time. Further, the shortness of this genera- 
 tion was, while not unexpected, not at all in accordance with any 
 
28 
 
 pul)lislu'(l statrnionts as to tho length of life of an}' immaturo mos- ■ 
 (juito of any sju'cics. But thcso pii})lisln'd statements, as jncvioiisly | 
 shown, were nearly all })ase(l uj)()n o))servations made in a eolder 
 climate and in tlie month of May. 
 
 lirmtirls on otluv sjfecies (tf Vulex. — The writer is inclined to ]>elieve 
 that (uh^x Uvnhn'hynchux (tig. .5) is more or less specifically the sea- 
 coast mosquito of the Atlantic seaboard; that is to say, it is the 
 mos(juito in this j)art of tlie country wliicii is ai»le to breed and prefers 
 to bleed in the luackisli swamps wliicli are occasionally overflowed at 
 hi«rh tide, it has been found by Mr. ('. W. Johnson at Avalon, 
 Ant^desea, and At iantic City, N. J.; by the writer at Far Kockawav. 
 Ameriranx'tl. and <>ii liie b(':i<li at Staten Island. New "^'ork : bv Mr. 
 
 ^' 
 
 Fig. 5. — Cuhjc l:iiiii>rh!/iichu.s : Female, showing the sliort palpi which 
 distinguish Ciilrx from Aitt>itfiili.<: {t>^\Xh^^^\ front tarsjil claw at right — 
 enlarged (original). 
 
 Barber at Chesapeake Beach, Md.. and a^fain l)v Mr. Johnson at St. 
 Aut^ustine and Charlotte Harbor, Fla Other species, like i'ulcx pim- 
 ge}if<^ are seen at seaside resoits. but it is probable that these breed 
 back of the coast in fre.sh water. This ditierence in breeding habit is 
 very mark(»d on thi* east coast of Staten Island. The people there 
 distinguish ])etween the browndegged mo.scjuitoes and the ring legged 
 mo.scpiitoes, the former being (\ pu?ige?is, which breeds in the hilly 
 ponds and swamps })ack of the bluffs, and the latter being ('. t(Siu<t- 
 rJn/ncas^ which breeds in the brackish marshes below the blulTs. Dr. 
 A. 1). Hoi)kins .states (Bulletin 17, new series, Div. Entom., Dept. 
 Agric.) that what is j)roba]>ly this spinies apj)arently l)reeds in West 
 
29 
 
 Virginia in pools and small streams fed from coal-iiiiiic draiimuc tlii^ 
 water of which contains a laro^i* ]icrccntati(* of sulphate of iron. 
 
 Cfflc.r 'nnphjer has ])con found hy Mr. Pratt, of this ofKcc, brecdinc^ 
 in privy vaults in Alexandria, Va., and this species is likely to be the 
 one found usually in such places where the water is fouhnl with decom- 
 posing or excreted animal matter. 
 
 CuleiP taeiilatus is said by Dr. Veazie, of New Orleans, to be the 
 so-called ''day mosquito" of New Orleans; that is, the form which 
 flies and bites in the daytime. This stattMuent is corro])orated to a 
 certain extent ))y Dr. St. George Gra}', of St. Lucia, British West 
 Indies, who writes, under date of August 12 last: 
 
 I have made some observations on the hours at which the different species are 
 most industrious, and find that most mosquitoes have regular feeding times. For 
 instance, C. ixniatus is very vigorous and troublesome in the early afternoon (between 
 noon and 3 p. m). Then she usually takes a rest, and renews her attacks at 9 or 
 10 p. m. During the morning it can be found resting on walls and clothing, particu- 
 larly dark-colored clothing, and is easily caught. 
 
 The distribution of the species of Culex in the United States. — In 
 preparing Bulletin No. 4 the writer was at pains to borrow all of the 
 mosquitoes from the collections of such entomologists as he supposed 
 had saved specimens in this family and placed them in the hands of 
 Mr. Coquillett for stud3\ The material received was not large, since 
 mosquitoes are difficult to preserve satisfactorih^ in a collection, and it is 
 an inexplicable fact that as a rule collectors do not save such extremely 
 common things as mosquitoes. Yet he was able from Mr. Coquillett's 
 work on the specimens received and on those already contained in the 
 national collection at Washington to show several interesting points. 
 As is the case with man}^ other species of Diptera, most of the differ- 
 ent forms were found to be ver}^ widespread. The whole group has 
 little or no faunistic value; that is to say, different climatic conditions 
 and other environmental factors do not limit the range of the species 
 as they do with those of other groups. It was thus found that some 
 of the commoner forms, like O. co?isohri7ius, C. excitans^ C. pet'turbans^ 
 and C. p)ostlcatus, and C. pungens, were found almost all over the 
 country, from New England to Texas and even to southern California, 
 so that in almost an}^ given locality in the United States one would be 
 able to find all of these common species of Culex, with two or three 
 species of other genera and possibly two oT three other species of 
 Culex. Since the publication of the bulletin (No. 4), other localities 
 of distribution have been ascertained, and the following list indicates 
 such actual localities as have come to our notice. Persons interested 
 will observe several points worth noticing' in the list which follows. 
 Certain species seem to be rare, while others are very common, in 
 addition to being widespread. It seems from the list that Cidex con- 
 sohrimts is a more northern form; that is, it comes nearer being 
 restricted to a boreal habitat than an}^ of the other species. It is one 
 
30 
 
 ol' tlu' two >|M(ir> wliicli wo li:i\<' iioiii Alaska. T\io othcM' Alaskan 
 loiiii wliicli lias Im'cm (ii'tonniiMMl. iiaiii('l\ . ( '. ////y^/V///. oxtonds south 
 to New Mexico. ( leoi-cria. and the island of Jamaica. 
 
 ('n/t.r fiinnitns, accoidiriii* to Ml'. Tlicohald, has a wide tropical and 
 subtropical dist i-il)ution. occuriin*:^ in \N'cst Africa. Indui. South 
 Europe, and Kast and West Indies, hut never in the north or south 
 cold temperate /ones. 
 
 Cri.KX CONSOHKIM S I )('>\ . 
 
 Ihihitat: Whit«' Mc.uiituiii.s, X. II.; lU-verly, Mius^., SeptemlM-r L'8 (Nat. MiiB.) 
 Catpkill Mniiiitaiiis, (Jreeiie (^mIlty, N. Y., 2,5(X) feet (Howard); Illinois, 
 March *JI, .Vpril L't>, May <>, OctolnT 1« (Xa«on); St. Anthony Park, Minn., 
 April, May, on snow (Lu^er ); Saskatchewan Uiver, British America; Sqjith 
 I)ak«ita ( Xat. Mus. ); Lincohi, Xe))r., May, Septeniln'r (Brnner); Colorado 
 (Xat. Mas.); Los Angeles, Cal., Fehrnary ( C'cxinillett ); Ar^'ns Mountains, 
 Cal., April (Nat. >rus.); Santa Fc, X. Mcx., July (Cockerell); Xew Orleanp, 
 I^., Xoveniher (Thayer); Ottawa, Canada, May i ITnwMrdi; Suniniit, X. J. 
 (Holmes); Trenton, Ontario, May 24 (Fletcher). 
 
 C'ULKX KXciT.ws Walk. 
 
 Habitat: New Redfdnl, Mass. (Jolmsoii); Lincoln, Xehr., May (Bniner); Santa 
 Fe, N. Me.x., July (Cockerell i; La^^'an, British Columbia (Wirkham). 
 
 Cri.EX KX( KCciANs Walk. 
 
 Habitat: Ithaca, N. Y., July U (Comstock). 
 
 (.n.K.x FAsciATCs Fa))r. 
 
 IIal)itat: (ieorjria, .Xugust (Coquillett); Natchitoches, 1^., October 6 (Johnson); 
 Isle of Pines, West Indies (Scudder); Kingston, Jamaica, July 13 (Johnson )j 
 New Orleans, La., November (Thayer); ea.stern Texaj* (Woldert); Cuba 
 (I.^zear). 
 
 CULEX IMPIOER Walk. 
 
 Habitat: White Mountains, N. IL; Beverly, Mass., May 24, June 2 (Nat. Mus.); 
 Tthaca, N. Y., July l» and 17, August 2S; Wilmuth, N. Y., June 10 (Comstock); 
 Saskatchewan River, British America ( Nat.Mus. ) ; Minnesota( Lugger ) ; Loudoun 
 County, Va., August 26 (Pratt): Tyrone, Ky., July 14 ((iarman); Georgia 
 (Nat. Mus. ) ; Mesilla, N. Mex. (Cockerell) ; Isle of Pines, West Indies (Scudder) ; 
 Portland, Jamaica (Johnson); District of Columl)ia, Septeml)er 12 (Barlx^r); 
 Alexandria, Va. (Pratt); Ogdensburg, N. Y., Jiiiie M (Howard); Middletown, 
 Conn., June (Davis); Ottawa, Canada, May .SI (Howard); Chats liapids, Que- 
 I)ec, May 24 (Fletcher); Buckeye, Wash. (Nat. Mus.); Stikine River, British 
 Columbia ( Wickham). 
 
 CULEX rEKTCRBANS Walk. 
 
 Habitat: lakeland, Md., August 8 (Pratt); Virginia, August 17 (Pergande); Tick 
 Island, Fla., May 12 (Johnson); Texas (Nat.Mus.); Bay anion, Porto Rico 
 January (Busck); District of Columbia, September 1-5 (Barber); St, Elmo,Va.| 
 June, July (Pratt); Cu))a (Lazear). 
 Cri.EX posTicATCs Wicd. 
 
 HaV»itat: M(»ntgomery County, Pa., July 17 (Johnson); Texas (Nat.Mus.); 
 Loud«»nn County, Va., .Vugust (Pratt); Roanoke, Va., October (Thayer); Dis- 
 trict of C?>lumbia, June 10 (Bar}>er). 
 Ci i.i;\ iTNOE.xs Wie<l. 
 
 Habitat: White Mountains, N. IL; Beverly, Ma.«is., Sep em er 5; Cambridge, 
 Ma.»<s,, September Ifi to November o; Boston, Ma.«s. ; Baltimore, Md., Novem- 
 >)er5 (Nat. Mus.), Novend>er 26 (Lugger); Charlton Heights, Md., December 1 
 (Pratt); District <»f Columl)ia, January .SO, March 5, May 6 and 15, June 2%, 
 July 11, August, OctoWr 10, 15, 25, and 31, November 4, 8, 13, 16, and 23, 
 
31 
 
 Docemlier 2S (rVrjjando'); Itliaca, N. V., INFay I't), July 17, Anjuinf L'S (Coin- 
 stock); Illinois (Nason); ^Minnesota (Ln^r^rn); Lincoln, Nehr., Scplcinln'r 20 
 (Bruner); lj(.\xinu:t()n, Ky., NommuIut 10 ( ( iannaii ); New Orleans, La., Decem- 
 ber 17 (Howard); San Antonio, Tex., May '> (Marlatt); (Jeor^'ia, An^Mist 
 (Coquillett) ; Portland, Jamaica, (Johnson); Mexico City (Rarrett); District 
 of Cohnnbia, Anjrnst 22, 28, Sej>tember 1 (Barber); Jackson, Va., October 
 (Thayer); Woodstock, Va., June (TVatt); Newport News, \'a., October 
 (Thayer); Stillwater, Okla., June (Botrue); Philadelphia, Pa., (Woldert); New 
 (Orleans, La., Jnne (Veazie); eastern Texas (Woldert); Snnnnit, N. J., ]May 
 (La Rue Holmes); ^Nliddletown, Comi., June (Davis); Cuba (Lazear). 
 
 CULEX SIGNIFER Co(]. 
 
 Habitat: District of Columbia, June (Coquillett), jNIay, August (Barber); St. 
 Elmo', Va., June 4 (Pratt). 
 
 CULEX STIMULANS Walk. 
 
 Habitat: White ^Mountains, N. H.; Beverly, IVIass., June 2, July 9; Cambridj^e, 
 Mass., May; Jamaica Plain, Mass., August 25 (Nat. Mus.); Baltimore, Md. 
 (Lugger); Illinois, August 1, September 15, October 5 (Nason); Agricultural 
 College, Mich. (Gillette); Saskatchewan River, British America (Nat. ]\[us. ); 
 Lmcoln, Nebr. (Bruner); Colorado (Nat. Mus.); Ithaca, N. Y., June LS, 18, 29, 
 July 14, August 28; Wilmuth, N. Y., June 10 (Comstock) ; Georgia (Nat. Mus. ) ; 
 Bladensburg,Md.,May 27 (Barber); St. Elmo, Va., June 5 (Pratt); District of 
 Columbia, September (Barber), June 10 (Miss L.Sullivan); Ottawa, Canada, 
 June 1 (Howard); Ogdensburg, N. Y., June 3 (Howard); Rochester, N. Y. 
 June (Ewers); Summit, N. J., May (La Rue Holmes); Middletown, Conn., 
 June (Davis); Mesilla, N. Mex., October 26 (Cockerell); Tacna, Ariz., April 13 
 (Hubbard); Juarez, Mexico, May 12 (Cockerell); Summit, N. J. (Holmes). 
 CuLEx T^xiATus Wied. 
 
 Habitat: New Orleans, July (Veazie); Cuba (Lazear). 
 
 CULEX T.ENIORHYNCHUS Wied. 
 
 (Not the Cidex txniorhynchus Wied. of Arribalzaga.) 
 Habitat: Maine, August; Beverly, Mass., June, September 15 (Nat. Mus.); 
 Avalon, Anglesea, and Atlantic City, N. J., July 10 to. 29 (Johnson); Far 
 Rocka way. Long Island, N. Y., August 30* (Howard); District of Columbia 
 (Pergande); Georgia (Nat. Mus.); St, Augustine and Charlotte Harbor, Fla., 
 July; Portland, Jamaica (Johnson); Chesapeake Beach, ]\Id. (Barber); Balti- 
 more, Md. (Thayer); Plymouth, N. C. (Thayer); Galapagos Islands, February 
 1—4 (Snodgrass). 
 
 CULEX TARSALIS Coq. 
 
 Habitat: Argus Mountains, Cal., April; Folsom, Cal., July 3 (Nat. Mus.). 
 CuLEX TRisEEiATus Say, 
 
 Habitat: White Mountains, N. PI, (Nat, Mus,); Delaware County, Pa,, June 12 
 (Johnson); Washington, D, C, May 5 and June 10; Loudoun County, Va, 
 (Pratt); Near Baltimore, Md. (Thayer);- Roanoke, Va,, October (Thayer); 
 Middletown, Conn,, June (Davis); New Jersey (Woldert). 
 
 THE BIOLOGY OF ANOPHELES, WITH GENERAL EEMARKS. 
 
 So far as the writer can ascertain, no detailed illustrated account of 
 the early stages of any species of Anopheles had been published before 
 his paper in the Scientific American, above referred to.^ He con- 
 ceived it to be nearly as important that the ma'arial-bearing mosquitoes 
 should be readily recognized in their early stages as in their adult con- 
 dition. He was very fortunate in April of the present year in being 
 
 ^ See appendix. 
 
82 
 
 a})lr to socuro a l:ii'^'"o iiuiiiIht of t^ravid fiMiialos of AiutjthiliH tpiadri- 
 imiriihittis Say tliroutifh the almiulaiici'. of this species near the home of 
 one of liis assistants. Mi. Pratt, in Virj^inia, a few niiU's from Wash- 
 in<,^ton. Mr. Pratt was enthusiastic and assichioiis in coUectin*^ living 
 a(hdt>. and th.'se were kept in eontinement and their offspring reared 
 in hirge water jars (hiring April and May, llMHj. It may he mentioned 
 here that this species is without (loul)t identical with the European 
 Aitnjthihs iiHiridijh nnls Meigen, a fact which Mr. ('(xjuillett has always 
 strongly suspected, although he had no P^uropean material with which 
 to c()mi)are our American specimens. Dr. W. S. Thayer saw A. macu- 
 lijh tuus in (Jrassi's laboratoi'v in Italy, and on his return to this coun- 
 
 Fn.. < .— .\ii<>iiliilis i/iKiiiriiKtii iilntii.-: A<llilt. ii'.hIc jit Irlt, f( 
 
 tilt riirlit— tiiljirmd lorigiiial). 
 
 try tokl tlie writer that he thought the two forms identical. The 
 (juestion has now ])een definitely settled by Mr. F. V. Theobald, of 
 Kngland. who is monographing the mos(juitoes of the world for the 
 British Museum, and who writes us under date of May 28, lOUO, that 
 he has studied a large series of A. (jvadrivtnculatius received from 
 Canada and that *'they (^xactly tally with ^1. 7/uiculi'pe7i7iis,''^ 
 
 I, IKK HISTORY OF AXOPHEI.HS tH'ADRIMACULATUS. 
 
 TnK ADiLT. — The acc()m})anving dlustrations (figs. T), 7. S) will show 
 vciv wrll the gjMKMai api)earance of the adult insect. It is a rather 
 
33 
 
 lai'sio in()S(|iiit<) and is vorv r)l()()(l-lliirsty. It Is attracted to the house 
 in iiuiidHMs. 'VUv dillcrciu'cs Ix'twccn the mah's and t'cmah's arc well 
 brought out in the iUustratioiis, and the strik*m»;- feathciT Jinteniui' and 
 palpi of the male ivudcr it very conspicuous. The winj^- niarkinos arid 
 the color t)l' tlie pal})! ditrcrciitiate this s})ecies from our other s})ccies of 
 Anopheles, and the lonj>- pjilpi of the female at once distinguish it from 
 all species of Culex. 
 
 Fig 
 
 -Resting positions of Culex (at left) and Anopheles (at right), enlarged (redraAvn from a rough 
 sketch published in the British Medical Journal). 
 
 nesting/ position. — Owing to the publication of a field sketch made 
 at Sierra Leone by a member of the Ross expedition, and which is 
 here reproduced, the writer has been much interested in watching the 
 resting positions of the adult insects. He finds that when resting upon 
 a horizontal surface — such as the ceiling of a room or the covering of 
 the breeding jars — the insect clings with its four anterior legs in a 
 nearly perpendicular position, its beak thrust forward toward the sur- 
 face to which it clings. The hind legs are frequently in motion, but 
 as a rule hang downward with more or less of a bend at the knee joint 
 (femero-tibial articulation). When resting upon a perpendicular sur- 
 face, however — such as the side wall of a room or the side of a breeding 
 jar — the body is held only at a comparatively slight angle from the 
 surface. Sometimes it is nearly parallel with the surface. At other 
 times it assumes an angle of 10^ to 20^ (occasionally even as great 
 an angle as 30° to 40°), the proboscis being held nearly in a line with 
 the body. Here again the insect supports itself by the four anterior 
 legs, the hind legs dangling down with more or less of a bend at the 
 3949 3 
 
84 
 
 knee. This j>ositi(Mi is coininon t<> hotli iiuilcs and fonialos. and is illiis- 
 tnited at rii,'. s. When tho body is held parallel it will generally l)e 
 found that one of the middle or hind legs has been broken off. The}^ 
 Hre verv delieate and reatlilv break. 
 
 Fi«;. S. — Aftiial resting f»f)sltioiis i.i" A. 'jint'irimnailatiis on a horizoiiLHl reiling^ and on aside wall, 
 drawn from life — enlarged (original). 
 
 The writer has taken the li))erty of having fig. engraved from a 
 drawing sent him l)y Mr. C. O. Waterhouso of the British Museum. 
 Mr. Waterhouse made the drawing himself and wrote: "Whatever 
 
 ^'H'. 0.— Anopheles at left, Cnlox at right— enlarged (drawn by C. O. Waterhouse). 
 
 Miay be the attitude of Anopheles, it is all in one line. Culex is angu- 
 lar, humi)ba(ked.*' 
 
 Xoteaffomd,. — The peculiar hum of the mosquito is well-known. 
 There is a distinct difference l>etween the hum of Anopheltii quadrlma- 
 
35 
 
 oiJafiis and that of i\\v, comnioii .s])(M'ios of C'lilcx in that the foi-iiior is 
 noticeably lower in tone. The note of Culex as it approaches the ear 
 
 Fig. 10. — Anopheles quadrimaculatus: Group of 4-1 eggs deposited by a single female as 
 tliej- appear resting naturally on the surface of the water— enlarged (original). 
 
 is high in pitch ; that of Anopheles is certainly several tones lower 
 and of not so clear a character. In quality it is something between the 
 buzzing of a house fly and the note of Culex. Mr. Pratt states that he 
 can at once distinguish the two genera in 
 this way as he is sitting reading in the 
 house, and the writer feels quite sure after 
 listening to them in breeding jars that the 
 statement is correct. 
 
 These observations have been made with 
 an abundance of material, nearly 100 adults 
 having been under observation. 
 
 The eggs. — The well-known and often- 
 mentioned boat-shaped masses of eggs of 
 Culex are not even remotely resembled by 
 the Anopheles ovipositions, and the indi- 
 vidual eggs are equally dissimilar. In the 
 accompanying illustration (fig. 10) the egg 
 mass of Anopheles is illustrated for com- 
 parison with fig. 1. In Culex from 200 to 
 100 eggs are laid in a mass ordinarily shaped like a pointed ellipse, con- 
 vex below and concave above, all the eggs perpendicular, and stuck 
 
 Fig. 11.— Anopheles quadrimaculatus: 
 Egg from below at left, from above 
 at right — greatly enlarged (origi- 
 nal). 
 
8(> 
 
 cloiicly tojift'thiT at the .sides )»y hoiiie <riiiniiiy sec- rot ion, and arranged 
 ill rows. 'I'lie. mass with Anopheles, however, is laid loosely upon the 
 siirfaee of the water, each v^rg lyinj^ upon its side instead of being 
 plaeed iij)on its end as in tln^ ej;«r mass of C'ulex. They are not attaelied 
 togetlu'r except that they naturally Hoat elose to each other and there 
 are from 40 to U)() ej^jrs in each lot. In ('ulex 'jyiuajrixH the individual 
 e^ir is n.7 mm. loiii^- and (>. 10 mm. in diameter at the base. It is 
 slender, luoadri-. and blunt at the ]>ottom, slenderer and more pointed 
 at the tip. Tiie tip is always dark t^-rayish Ijrown in color, while the 
 rest is dirty white. Th(», ejrir of Anopheles when seen from above is 
 of II rather re»,'-ular elliptical outline, the two ends having practically 
 the same shape; seen from the side, it is strongly convex below and 
 nearly i)laiu' al)ove; seen from below, it is dark in color and when 
 examined with a hi<rh power is seen to be covered with a reticulate 
 hexa«4()nal sculpturing. At the sides,-in the middle, there appears a 
 clasping nuinbrane with many strong transverse wrinkles. Seen from 
 above, the v^^'^^ is l)lack except for a clasping membrane which nearly 
 
 Fiti. V2.—Annphcks qiuulrimacidatuf: Newly liulched larvH— greatly enlarged (original). 
 
 meets on the middle line in the middle third of the ])ody, but retires to 
 the extreme sides for the anterior and posterior thirds. At each end 
 the color is lighter, with a group of from 5 to 7 minute dark circular 
 spots. It is O.oT mm. long. Eggs laid April 2*) hatched April 30. 
 Others laid .May lo and U hatched :\lay Kl and 17. 
 
 The I.ARVA. — The lar\ais cpiite as unlike that of .Culeo' j}u?i(/e}is »s 
 is the i'^f<f. It differs in structure, in its food hal)its. and in its cus- 
 tomary position so markedl}' that it can at once be distinguished with 
 the utmost ease. The larva of Culex, it will be remembered, comes 
 to the surface of the wtitcu* to ])reathe, thrustini^ its breathing tube 
 throui^h the surface laver and holding its l)odv at an angle of about 
 45 degrees with the surface of the w^ater. While in this position iti» 
 mouth parts arc in motion and it is taking into its alimentary canal 
 such minute ])articU\s as may be in the water at that depth, l)ut these 
 are naturally few in iunn])er and the larva descends at frequent inter- 
 vals toward the liottom to feed. The want of oxygen, however, causes 
 it to wriggle up again to the surface at very frequent intervals. Its 
 
37 
 
 specific gravity soonis crroatcM- tluin tluit of water, so that it roaches the 
 surface only ))y an eH'ort, and th(^ writci- lias already pointed out in the 
 case of (\ j>un(/<'ns tliat when the lar\a l)cconl(^s (MifcM'hh'd and is not 
 strong enough to wriggle up to the surface it drowns. Feeding" as it 
 does at the bottom upon t!M> heavier })artich*s which sink, its specific 
 gravity is explained. 'V\\v lar\a of Anophrhs quddrinHicuJdf^i.s^how- 
 ^^WidV^ habitually remains at the sui'face of the water. Its l>reathing 
 tube is very nuich shorter than that of Cuh^x and its Ixxly is held not 
 at an angle at the surface, but practically parallel with the suifaee juid 
 immediately below the* surface lilm. so that portions of its head, as 
 well as its breathing tii))e, are practically out of the water. Its head 
 rotates upon its neck in a most extraordinar}- way, so that the larva 
 
 Fig. 13. — Anopheles quadrimaculatiis and Culex imngens: Half-grown larva at left and in center, in 
 comparison with half-grown larva of Culex pungens at right (figure at left has been cleared) — 
 greatly enlarged (original). 
 
 can turn it completely around with the utmost ease and feeds habitu- 
 all}^ with the under side of the head toward the surface of the water, 
 whereas the upper side of the body is toward the surface. In this cus- 
 tomary resting position the mouth parts are working violently, the 
 long fringes of the mouth parts caiLsinga constant current toward the 
 mouth of particles floating on the surface of the water in the neigh 
 borhood, which thus gradually converge to this miniature maelstrom 
 and enter the alimentar}^ canal. The spores of algji?, bits of dust, 
 minute sticks, bits of cast larval skins, ever^^thing in fact which floats, 
 follov/ this course, and, watching the larva under the microscope, the}^ 
 can plainh^ be seen to pass through the head into the thorax until they 
 
38 
 
 aro ohscurod ])y tlic dnvk color < f the inscM-t's ))j\(k. Orcjisioiially too 
 lar«r«' Ji fra*ruHMit to Ik'- swallowed with case cloofs the iiiouth. Some- 
 tiiiirs it i'nt«Ts the iiKuith and sticks. In such cases the head of the 
 hirva revolves witii lij^htniiii^-likc iiipidity and the fragment is nearly 
 alwa\-^ dis*;ort»'cd. althoiij^h sometimes it is swallowed with an evident 
 ctioit. Since the Aiioplielcs lar\a t'ct'ds only iH)on these li»i"ht tloatin^r 
 particles, its specitic t^ravity is nearly that of the wat<'r itself arid it 
 suppoits this JMnizontal position just heneath the surface tilin with 
 comi)arative eas<'. and in fact without eti'ort, the tension of the surface 
 — Him itself being 
 
 hardly needed to 
 h(dd it. It requires 
 an etlort in fact for 
 the Anopheles larva 
 to descend (which it 
 apparently n e v e r 
 does up to the period 
 of the final larval 
 stage, except when 
 alarmed), while it 
 requires an etiort 
 for the Culex larva 
 to ascend. 
 
 Structurally the 
 ditferences between 
 the h a 1 f - g r o w n 
 larva? of Culex and 
 Anopheles are well 
 shown at tigs. 18, 14, 
 and 15. The great 
 size of the head of 
 Culex, as conti-asted 
 with the small head 
 of Anopheles is a 
 most striking differ- 
 
 Fio. H.— Figxireat lop. half grown larva of Anopheles in feeding posi. 
 lion, jusl biMuatli surface lilni. Figuri" at bolt«>m, half grown larva euce 
 of CnK'x in hrt-athing jjosilion— greatly enlarged (original). i 
 
 r h e y (» r y 
 respiratory 
 
 siphon (as Miail calls it) of Culex contnists markedly with the short 
 one of Anoi)heles. Tlie arrangement of the hairs is entirely diti'erent, 
 \hv ))ranching of the hairs of Anopheles, as contrasted with the simple 
 hairs of Culex and the little paired stur-shaped (apparently branchial) 
 tufts on the dorsum of Anopheles are entirely al)sent with Ciil(\\. The 
 flaps at the tail end of the body are similar in number, but are held in 
 asomewiiat ditb'rent position. 
 
39 
 
 The larvae first studied — thost^ wliicli luitclicd from the cj^^os on 
 April 30 — grow very slowly for a nuinbor of da3's. 'I'll is was partly 
 owing" to cool woathor in the early part of May, and partly, I believe, 
 to the absence of proixM- food. They were reared in ghiss jars of water, 
 with sand at the bottom and a willow twig rooting in the sand. As 
 above noted, they 
 swallowed every 
 small particle floating 
 on the surface of the 
 water, and the dark 
 coloration shown in 
 tig. 14 was largely- 
 due to the fact tha 
 most of these fooc 
 particles were dark 
 colored. About the 
 10th of May, the 
 larvae having passed 
 through two molts, 
 a small quantity of 
 the green alga? grow- 
 ing on the lily ponds 
 on the Department 
 grounds w^as placed 
 in the jar. ^ The larvae 
 commence to thrive 
 much better, grew 
 rapidly, and the gen- 
 eral color of the body 
 changed to green. 
 The description of 
 the habits given 
 above held well until 
 after the last molt 
 preceding the change 
 to pup^e. In this final 
 larval stage, as shown 
 in fig. 15, the diameter fig 
 of the thorax became 
 much greater in com- 
 parison with the rest of the body. The larva was less marked, more 
 inconspicuous, and altered its feeding habits to some extent. After 
 
 ^ These algae were studied by Mr. A. F. Woods, of the Division of Vegetable Phys- 
 iology and Pathology, who informed me that the larger part belong to a species of 
 the genus QEdogonium, but that there was also quite a large amount of a species of 
 Cladophora, with some Spirogyra. There was also some of the blue green Oscilaria. 
 
 15.— Anopheles qaadrimacalatus: Full grown larva in feeding 
 position, seen from above (head reversed, in feeding position); 
 dorsal side of head above at right— greatly enlarged (original). 
 
40 
 
 ronmiiiin^at tho surface of tho wjitor, feeding, as before, upon floating 
 particles for some Hme, it would wriggle violently and descend to the 
 hottoni, where it would remain frecpiently as long as two minutes 
 before reaseending to the top. Its appetite was evidently so great 
 that it was not satisfied with the floating particles, and when it descended 
 to the }M)tt<)in it mouthed the jKirticles of sand, evidently swallowing 
 the slime on tiie little stones and frequently even picking up (juite a 
 a large s:md pehl>le and th«Mi droj)))ing it again. In this stiige the indi- 
 \i(lual which grew most ra})i(lly remained only four days, and trans- 
 formed to ])U})a on the morning of the 1 7th. after a lar\al exist4»nce of 
 sixteen days. The accompanying iigures of the larva' have been dniwn 
 witii such caic that detailed desciiption will ])e unnecessary. They 
 w«'re drawn from life under the compound microscope. Some of the 
 stiuctures are puzzling, notably the organs occuring on the dorsum of 
 the a)>dominal segments, shown most plaiidy in tig. 15, and w hich look 
 as though they might ]ye spiracles until they are examined under a high 
 power in the cast skin. The writer d(K's not care to risk an expression 
 of opiidon as to their function, although possildy it is known, and they 
 possibly occur in other acjuatic dipterous larva\ In the early stages of 
 the larva' they resend)le minute hranchial tufts, lait no tracheal con- 
 nection has been found. 
 
 1 UK I'UPA. — The accompanying figure (tig. 16) well represents the 
 
 Fig. 16. — I'upu (if Ciilr.r jni)ii;t IIS at U-ft: juipji of Annpfirirs qumlrimaculalus &t risiht — prn^atly enlarged i 
 
 (original). j 
 
 difl'erences ])etween the i)upa of C'lilex and that of Anopheles. In this 
 stage the insects of the two genera an^ not so markedly diflerent as in 
 the larval stage. Structural dirfVrences need not l)e described, as the}' ; 
 are sufliciently shown in the illustration. The (\ve will at once l3e j 
 caught hy the diflerence in position, the pupa of Culex resting in a \ 
 more |)erpendicular attitude than that of Anopheles, and the marked 
 difference ifi shape between the respir.itory siphons, which issue from 
 the thorax instead of from the anal end of the abdomen, will at once 
 
41 
 
 be noticod. Tho pupa of Anopholos is quite as aotivo, when flistur))0(l, 
 as is that of Culox. If one toiiehes the* near-hy surface of the wattn' 
 with the finger the pupa at once wriggles violently away, returning 
 shortly to the surface for air. 
 
 The duration of the pupal stage in An()phel(\s varies according to the 
 weather. Five days was th(^ niininuun ()])served during June, although 
 several specimens rtMuaincd in this stagi* for ten days. The adults issue 
 as do those of C'ulex. 
 
 The entire life round. tluM'efore, of Anophdex quddrimdmhifux in 
 the generation studied by the writer is as follows: Vj^^^^ stage, three 
 days; larval stage, sixteen days; pupal stage, five days; making a total 
 period in the early stages of twenty-four days. It should be stated, 
 however, that during the early larval existence toward the end of May 
 there occurred nearly a Aveek of cool weather, so that it is certain that 
 in the hot season in July and August the growth and transformations 
 will be more rapid. It w411 be remembered that the writer traced 
 Culex pimgei}.^ through an entire generation in the latter part of June, 
 1895, in ten days. 
 
 NATURAL BREEDING PLACES OF ANOPHELES. 
 
 Having accomplished the preliminary work of studying different 
 stages of growth of Anopheles by breeding from captured females, we 
 were enabled to become familiar with the larvae and pup^e so as to 
 recognize them readily and it was then not difficult to find the natural 
 breeding places. The first breeding place discovered was in Maryland, 
 and the larvse found there were those of what is probably A. puncti- 
 penni.^. They closely resemble the corresponding stage of A. quad- 
 rimaculaMis except in the maculation of the head. A figure of the 
 head of this form is shown here (fig. 17) in order that it 
 may be compared with the corresponding figure of A. 
 quadrimaculatus shown in fig. 15. This first breeding 
 place of Anopheles was a small permanent stream run- 
 ning through the woods which had here and there ])road- 
 ened out into little shallow\s. and in these shallows the 
 Anopheles larvje were found resting at the surface of fig. \i .—Anopheles 
 the water, and occasionallv darting from one spot to pnnctipennis: 
 
 1 1- i" 1 1 1 1 Head of full- 
 
 another. All ot these little pools were abundantly sup- grown lana from 
 plied with alo'?e, and from specimens brought in Mr. above— enlarged 
 
 ^ » ' L r^ (original). 
 
 A. F. Woods has found that the}^ l)elong to the genus 
 Mougeotia. There were also many Diatoms present. The next natural 
 breeding place found was in pools about a disused spring in Virginia. 
 At the sides of the spring were several more or less permanent pools 
 of considerable depth (8 to 10 inches). Here the larvjB of A. quad- 
 rhnaculatim were found. Alga^ also occurred here and ]\Ir. Woods has 
 determined them as belonging to the same genus Mougeotia. The 
 
42 Ja. 
 
 toiiijx'ratui'c of this wator was Is^ C. The third locality was an old 
 canal IkhI so nrarlv dried out after a season of drought that the water 
 lay in lather small puddl"s. In this ease the water was ver\^ foul and 
 alj^a' of the trenus Lynj^^hya were pi'esent. The teni})eraturc of this 
 watei- was *jr» (\. and the conditions were those of (^xtreuie stajii^nation. 
 The tiisi hxality was discoNcicd hy the writer in company with Mr. 
 Pratt and the second and thiid were found hy Mr. Piatt. Later, the 
 wi'itei- in <<)in|)any with Mr. Husck and Hospital Steward Smith, found 
 empt\ j)iipa skins of .1. «ji((ti/rtin(i<-uhifiis in a di'ied up surface pool at 
 the \\'ashin<rton Pairacks, at a time when malaria was very prevalent 
 amon^:: the troops. I am informed hy Dr. Thayer, of Baltimore, that 
 Dr. Lazear found ,1. jHi/irtij}rnnit< })reeding in a stone quarry near 
 Baltimore, in the suuunerof 181>1). Ro.ss found in India that while the 
 species of Culex jjf(*nerally hred in vessels of water around the houses, 
 the species of tin* ij^enus Anopheles hred in small pools of water on 
 the trroiind. This point was made the suhject of a special investiga- 
 tion hy the e\])editi()n of the Liverpool School of Tropical Medicine 
 to Siei-rti Leone. While Culex larva* were to he seen in almost every 
 vessel of water or emi)ty gourd or flowei'pot in which a little rain 
 water had collected, in oidy one case were Anopheles larva' found in 
 .such recei)tacles. On the other hand, they occurred in ahout 100 
 small })uddles .scattered throughout the cit}^ of Freetown — puddles 
 mostly of a fairly permanent d(\<cription, kept tilled hy the rain, and 
 not liahle to washing out during heavy showers. It was noticed also 
 that the larvai seemed chiefly to feed on green water weed. 
 
 In the interesting and important pap(M- hy Dr. J. W. W. Stephens 
 and Mr. S. K. Christophers entitled "The distribution of Anopheles 
 in Sierra Leone," published in the report of the malarial eonnnittee of 
 the Royal Society, July <>, liHJO, it is stated that at Freetown not 
 only do the larvie of Anopheles exist in the small pools in the rocks, 
 but also in the pools by the sides of streams and in certain small 
 drains, and that in th(» dry season, in the ab.sence of the rock pools, 
 Anophides breeds freely in streams and drains; also, in the drv season, 
 the adults exist in mo.st parts of the town in dwellings, especially in 
 overcrowded native huts and native quarters, ready to lay their eggs 
 when pools appear. It is inter(\sting to note, from this latter okser- 
 vation, that the authors of the paper recommend the destruction of 
 dirty huts and the prevention of excessive overcrowding. Outside of 
 the city, in the '* luish,'' Anopheles larviv were present throughout the 
 whole district. In the mountain streams, wherever there were suitable 
 pools, nudtitudes of larva^ existed. In tracing the mountain .stream.s, 
 occasionally for a half mile or so, they found no larva\ but then a 
 rock pool occurred, and there they were again found in nund>ers. At 
 Songo and Mabang they were able to detect Anopheles larvae in the 
 swamps. They were not present in the main swamp water on account 
 
43 
 
 of tho innuin(M*5i])l(* small fish, ])ut wcm'c occiisionsilly ohscrvcd in sinall, 
 isohitcd [)()()ls on the iniul, and wiM'c still more common in small pools 
 at the ed^'os of swamps. It is a notcwoi-thv fact (hat they did not 
 occur in swam}) pools in such mnnhcrs as in the streams and rock 
 pools amono- thi^ hills of Sierra Leone. ** These i-ock pools would 
 appear to be the most suitable condilions for the IncedinL;- ot 
 Anoph(des.'' 
 
 The avidity with which Ano})holes larvii? under observation in 
 Washington fed upon algte sporcvs of the j^enera previously mentioned, 
 and the chai'actiM' of the breeding- pools found here, indicate that with- 
 out doubt snnilar conditions will prevjiil geneially in this country, and 
 Anopheles will always be found to breed most abundantly in fairly 
 permanent stagnant pools of water uninhabited by tish, but more or 
 less covered with green scum. 
 
 OTHER SPECIES OF ANOPHELES. 
 
 As appears from the synoptic table on previous pages, we hav.^ in 
 the United States, so far as ascertained, three recognized species of 
 
 Fig. 18. — Anopheles punctipennis: Female, with male antenna at 
 right, and wing tip showing venation at left — enlarged (original). 
 
 this genus. A. quadrimaculatus has just been figured in all its stages, 
 and the accompanj' ing illustration (fig. 18) shows very well the beautiful 
 
44 
 
 sjHM'irs known jis A. jtftnrf/'jtr/i/f/'s Sjiy. .1. r/v/r/V/z/.v (fi<r. 19) sooms to 
 ln'iairj- than tlir otlicr two and has hccMi tnk«Mi only in a few instances 
 
 . i<i. \9.— 'Anopheles rnicians: Feraak- — i'nhirge<l (original). 
 DISTRIBl'TION OF THE SPECIES OF ANOPHELES IN THE UNITED STATES. 
 
 Anopheles crucians Wied. 
 
 IIa])itat: District of Coluiuhia, Ajiril 27 (Pergande); Georgia (Nat. Mus.); New 
 Orleans, I^a., .Tuiie2S ( Veazie), NovemlHT (Thayer); Rieluiiond, Va. (Sk>s.**on). 
 Anopheles inNrrn'ENNLs Say. 
 
 ( (\)nsidere<l hy AViedcmaini to be tlic same s}>e('it's as his Aiwpheh','< rrnrianj*, Imt 
 
 the tw<) are certainly <listinet.) 
 Habitat: Castleton, Vt., February 1 (temperature 6° F. ); Beverly, Mass., Sep- 
 tembi^r 19, October 2; Cambridge, Mass., June !(>, September 80, Octolx»r 20 
 (Nat. Mils.); Charlton Heights, Md., March 81, Novendx^r 17 (Pratt); District 
 of Columbia. June (iand 7, October 15, 2o, and 81 (Pergande); Philadelphia, Pa., 
 OctolH'r 12 (JohiLson); Ithaca, N. V., April 17, August 2S (C\>mstock); Illinois 
 OctolH'r 1() (Na.'^on); Texiis (Nat. Mus.); Mesilla, N. Mex. (C<x'kerell); Port- 
 land, Jamaica (.lohnson); Middletown, Conn. (Davis); Sunnnit, N. J., April 2() 
 (Howard); RoaiiokcVa., ()ctolx«r (Thayer); St. Elmo, Va., May, June (Pratt); 
 Brazos River, Tex. (Woldert); Baltimore (Thayer an<l I^zear); Walbrook, 
 Md. (Thayer and T^zear); Onaga, Kans. (Crevecoeur). 
 Anopheli-x tirADKiMAciLATrs Say. 
 
 Habitat: Berlin Falls, N. H., August (Nat. Mus.); Ithaca, X. Y., January, July 
 81,NovcndH'r28(Coiustock); Lakeland, Md., AugustH; Charlton Heights, Md., 
 
 L 
 
45 
 
 NovoiiiIk' 24 (Pratt); District of ('oliiinhiii, .Inly, Octoln'r 15, Novrrnln'r L' iiiid 
 14 (I\M«;aii(U'); Illinois, St'ptriiilM'r 10, Octohcr i()(Nasoii); St. Anthony Park, 
 Minn., DociMnlu'r II (Ln<;^i'r); Tick Island, Fla., May 12 (Johnson); Texas 
 (Nat. Mus.); Oneco, Kla., May 2() ((iossani); Poan(>ki', Va., October (Thayer); 
 Newport News, Va., October (Tiiayer); St. Khno, Va., Ai)ril, May, June, July 
 (Pratt); New Orleans (Thayer); Sparrows Point, M(l.,an(l vicinity (Thayer 
 and Lazear); Middletown, Conn. (Davis). 
 
 TIIK (JKNUS I'SOiiOlMIOKA. 
 
 But one species, P. clllafu^ of the (^eiuis Psorophorji is known in 
 the Ignited States. This is Avell iUustrated in the {icconiiKinyiiijr 
 figure (hg. 20). Although this insect, as indicated in the synoptic 
 
 Fig. 20. — Psorophora ciliata: Female — enlarged (original). 
 
 tables, is really yellowish in color, yet the general effect when one 
 glances at it, or sees it flying, is that it is ver}^ dark, almost black. 
 The wings are not really spotted or infuscated, but the very numerous 
 dark scales on the main veins make the wings appear dark. They are 
 also when seen in certain lights prismatic in color effect. The palpi 
 of the female are nearly half as long as the beak, and the beak itself 
 
46 
 
 is vorv stout. Tho most striki?!*^ fcatiiro of this insect, however, is 
 the ciirioiis series of erect close-set hairs or scales on the le^s. which 
 (listinjj^uishes it at once from other mosquitoes. This mosquito is 
 widespread in tlie I'nited States, and we have specimens from Dorches- 
 ter, Mass. (Nat. Mus.); Washinoton, 1). C. (Chittenden); Westtield, 
 N. J.. July :i (Johnson); Illinois (Nason); Brooklyn Bridge, Ky.,»Iune 
 'J.S ((rarman); Lincohi, Nelir., July and Aujifust (Bruncr); Los Angeles, 
 ( al. (('(Kjuillett); San Diego. Tex.. May 15 (Sihwarz); Florida, July 
 (Nat. Mus.); Hastings, Fla., July (Dept. Agric); New Orleans 
 August, (Veazie). A rather large series was captured in June of the 
 
 Fig. '21. — Megarhimis riUilns: Female— enlarged (original), 
 
 present year at St. Elmo, Va., by Mr. Pratt. The writer felt certain 
 that he would be able to follow out the life history of this species from 
 the living material captured ])v Mr. Pratt. Females were placed alive 
 in })reeding jars under conditions which had repeatedly been successful 
 with Culex and Anopheles, but no eggs were ol)tained. The breeding 
 hal)its, therefore, may })e different from those of the other two genera, 
 and the biology of this form is an interesting and important point for 
 future investigation. As elsewhere stated, the possible relations 
 between Psorophora and the I lamiatamoebae deserve early investigation. 
 
47 
 
 THK (J KNITS MKGARHINIJS. 
 
 This is the other oimhis (ti<^. 21), the s])e('ies of which ;ir<> more or 
 less {il)UiKliiiit ill the South, wiiich slioiikl l)e iiivesti<i-5ite(l hy Southern 
 observers in rej^ard to its possihh* eoniieetion with nmhiriii. As indi- 
 cated in the synoptic t4il)h\ the nios(juitoes of this ocmuis ai'e readily 
 distinguished l)y the curved h(»ak. wliich is also well shown in the draw- 
 ing*. Thi'v are especiall}^ distinguished also by their metallic greenish 
 or bluish coloration. Nothing is known of the life history of the mos- 
 quitoes of this genus, and the species known to occur in this country 
 are distributed as follows, so far as our records go: 
 
 Megaktuncs fekox Wied. 
 
 Habitat: District of Colombia, August 22 (Pergande); (Georgia according to 
 Walker's list). 
 Megarhixls h^morrhoidalis Fabr. 
 
 Habitat: (Cayenne and Cuba according to Osten Sacken's catalogue). 
 Megarhinus portoricensis Roeder. 
 
 Habitat: Benoit, Miss., July 18 (Hine). 
 Megarhinus rutilus Coq. 
 
 Habitat: North Carolina; Georgiana, Fla. (Nat. Mus.). 
 
 Fig. 22.— Aedes sapphirinus: Female— enlarged (.original). 
 
 THE GENUS AEDES. 
 
 The mosquitoes of this genus (fig. 22) are minute forms, insignificant 
 in color, and the only one of which we possess specimens, viz., A. sap- 
 phirimcs, is shown in the accompanying figure. We have received it 
 
48 
 
 only from Ithaca. N. V., llinmj^li the kiiidiu'ss of Prof. ,1. H. Coin 
 stock. Another spccii's, . I. /'//>< //.s, i^ said by Osteii Sueken to occur 
 at Cauil)ridg'e, Mass. 
 
 THK NATUKAL KNEMIES OF MOSgUITOES. 
 
 Tlir late l>r. Kohcrt II. Laiiihorn, of New York and Philadelphia, 
 while eno-at^^ed a nmnl)ei- of years aj^o in huildin<r the I^ike SiHK*rior 
 and Mississippi Kadroad, fell in with a jj^reat many mos(iuitoos. He 
 ofton, ''with a sentiment of gratitude/' as he expressed it, looked 
 throujxh his mostjuito veil at the drat^on Hies which collected in the 
 open spaces among the pine trees. "They darted from side to side, 
 like swallows in a meadow, but with amazing rapidity, and at every 
 turn a moscpiito 'ceased from trou})ling.' " This gave Dr. Lam))orn 
 the idea that pi'rhaps dragon flies might be domesticated and utilized 
 to destroy mosipiitoes along the New Jersey coast and elsewhere; and 
 so he ottered prizes for the three best essays regarding methods of 
 destroying the moscjuito and the house fly, especially designating the 
 dragon fly for careful investigation. The successful essiiys — by Mrs. 
 C. B. Aaron, Mr. A. C. Weeks, and Mr. William BeutenmfUler — were 
 pu))lished ))y Dr. Lam])orn in a volume entitled '' Dragon-Flies v'«. 
 ^los(iuitoes. The Lamborn prize essays." The essays were all excel- 
 lent. Here, howcNcr, they are mentioned, by the way, in connection 
 with the group of the best-known natural enemies of mos(|uitoes, 
 namely, the dragon flies. It is needless to say that none of the essa3'S 
 were able to solve the prolilem of a practical breeding, on a large 
 scale, of dragon flies for mosijuito extermination, and, in fact, the 
 whole subject of the natural enemies of the mosquito is of little 
 practical importance. It is simply a matter of geneml interest. 
 Dragon flies, as adults, feed upon adult mos(juitoes, just as they will 
 upon all other insects which they are able to capture and devour. 
 Dragon flies, as larva*, feed upon the larvte and pupa? of mosquitoes, 
 although other and larger and less active aquatic insects and small tish 
 form the bulk of their food. 
 
 The extreme activity of both larMc and pupie of mosquitoes is a 
 necessary factor in their struggle for existence, since stagnant pools 
 of water fairly swarm with predatory animal life. The larva of one 
 of the water l)eetles of the family Hydrophilidic eats hundreds of 
 other insects in the course of its existence, and the larvte of mos(iuitoes 
 do not escape entirely, although by their extreme activity they stand 
 a }>etter chance than do other more sluggish species. A small pool of 
 watei- on the Department grounds at Washington is situated near a 
 manure ]/ile. and the water is colored dark brown by the dminage 
 from the manure. The })ool is kept ])y Mr. Saunders, the superin- 
 tendent of the grounds, for tiie i)urpose of securing manure water 
 for some of his plants. It is, at all times through the suiumer, 
 
49 
 
 swarm iiij,'- witli tUv lar\ii' of ('t(/r,r jniini,its^ ('. stiiin(/ans^ and ('. per- 
 turh<Uif<; also with tlir larva of an Kphydrid lintr/u/ilrittmi tinjr/ifdfa 
 Walk. — and with the larva of an Kplicincrid of the j^fcniis Ctiinis, and 
 other a(iuatic' species. A niunber of s})eeiniens of IIydi()])hilid lar\ a' 
 were found by the writer in this pool. They fed \\\)n\\ the other 
 aquatic insects with axidity, and three of them were phiced in a lai^^c 
 battery jar with a))()ut a half gallon of this water, teemino- with insect 
 life and containing- apparently some hundreds of tlie moscjuito larvie 
 and many of the others just mentioned. Th(\sc three Hydrophilid 
 larva\ in the course of ,a week, practically devoured all of the other 
 animal life in the jar. Only tw^o male mos(iuitoes and one female suc- 
 ceeded in reaching the adult stage. 
 
 No one can realize the intensity of the struggle for existence which 
 is going on in a stagnant pool until he forces himself to the seemingly 
 rather unpleasant occupation of l3"ing down by its side and watching 
 with a large hand lens the various forms of life with which the water 
 is swarming. Aside from the larva; of the dragon flies and the preda- 
 tory larvce of the three great families of aquatic beetles, namely, the 
 Dytiscidai, the Hydrophilida^, and the Gyrinidte, there are aquatic 
 neuropteroid insects which are predatorv and which feed upon 
 mosquito larva? as well as others, like those of the genus H^dro- 
 ps3xhe; and there are aquatic Heteroptera which are also predatory. 
 
 Aside from insects, there are many other natural enemies of mosqui- 
 toes. Many fish eat their larva? and pupae, and such night-flying birds 
 as nighthawks and whip-poor-wills, and bats as well, destro}' the adults. 
 Harve}^ (American Naturalist, 1880, p. 896), quoted by Mrs. Aaron, 
 found 600 mosquitoes in the crop of a nighthawk. 
 
 REMEDIES AGAINST MOSQUITOES. 
 
 Remedies in houses and the prevention ofhites. — Of the remedies in 
 use in houses the burning of pyrethrum pow^der and the catching of 
 mosquitoes on the walls in kerosene cups are probabl}' the best, next 
 to a thorough screening and mosquito bars about the bed. In burning 
 P3^rethrum powder it is well to moisten the powder sufficiently with 
 water so that it can be molded roughW into little cones about the size 
 of a chocolate drop. These cones are placed on a pan and dried in 
 the oven. If ignited at the apex the cones smolder slowly, giving off 
 an odor not unlike that of the prepared punk which bo3^s in this 
 country use to light firecrackers. Two or three of these cones burned 
 in a room in the evening will give relief b3^ stupef34ng the mosquitoes. 
 This smoke appears to be perfectl3" innocuous to human beings. The 
 writer has breathed it evening after evening without the slightest per- 
 ceptible ill effect. The method of catching mosquitoes on the walls 
 with kerosene in cups is now in frequent use in different parts of the 
 3949 i 
 
50 
 
 fomitrv. No one srcins to know who invciiti'd it. ])ut the writfi* tir>;t 
 saw it ill oiuTation some vrars a«:fo in N«'w Jersey, and was struck with 
 its siiii}>licity and ctlicacv. The top of a tin ))aki!ig-powd(M' l»ox is 
 iiiNcrtrd ar.d naih'd to the t'lid of a stick of yullicicFit h'lijrth to reach 
 to tlic ccilini:. A small <|iiantity of kerosene is jmt into this inipro 
 vised cup aiul the a[)pa!atus is puslied up undci- restinif iiiostjuitoes. 
 which fall into tlie kerosene and ar«* (h'sti'oyed. It is the custom in 
 certain iiouses to systematically hunt for iiiosijuitoes in the bedrooms 
 with such an ap[)aratus every ni^'^ht hefore reiirinj,'". 
 
 Camphor ruhhed on the face and hands or a few drops upon the 
 pillow at ni^rht will kei'p iiios((uitoes away foi* a time, and this is also 
 a well-known jirojx'rty of oil of pennyroyal. The use of oil of pepper- 
 mint, lemon juice, and vinej^ar have all been recommended as jiro- 
 tectoi-s aufainst nioscpiitoes, whiiv' oil of tiir jis used against the hlack 
 tly in Canada is also used in ])ad inos(piito localities. Strong-ly cam 
 phorated \aseline. althoutj^h recommended, has been found by Dr. 
 Nuttall to be of scarcely any use in Canada. 
 
 One of the London papers, the Daily Telegraph, invited its readers 
 to send in moscjuito remedies of this kind during the summer of 1899, 
 and some of the substances recommended were as follows: 
 
 FAicalyptol on the ykin, with a handkerchief saturated with it plact^l on tlie jiillow 
 at night — the result of South African experience. (Arthur E. PMwards. ) 
 
 Carbolated va.seline. (Dr. Geoi-ge Mackern.) a 
 
 One drop of oil of lavender on pillow, and one (^n the licad at night. (A. E. S, ) 
 
 Tincture of Ltd'j'm ^>oZ«-s/r.r. (M. Fisher.) 
 
 Piece of cotton wool soaked in oil of ch»ves on each side of the lied curtains. 
 (W. B.) 
 
 Anoint skin with o parts relined paraffin and I part crushe*! canii)hor. (\V. T. 
 Catleugh.) 
 
 To heal the bite«, a drop of iitpiid ammonia. (P. G. L.) 
 
 Eucalyptus oil. (X.) 
 
 Same substance. (Dr. George Gohen.) 
 
 Oil of eucalyptus and creosote, each 5 drops, to l>e thoroughly mixe<l with I ounce 
 of glycerin. (R. R. P. S. Bowker.) 
 
 Place a line, juicy, uncooked l)eefsteak near the l>ed on retiring. (M. M. M.) 
 
 A substance with which the writer is not familiar, but which is 
 spoken of very highly in the interesting paper by the Italians Celli 
 ;ind Casagrandi in a paper to which we shall have occasion to refer 
 later in speaking of remedies against the larva, is a yellow aniline color, 
 referred to in the work of the Italians a^ Larycith III. They state 
 that a little of this substance burned will kill the adult mosquitoes 
 and that this method constitutes the most efficacious means of destroy- 
 ing them. The Chinese use pine or juniper sawdust, mixed with a 
 small (piantity of brimstone and 1 ounce of arsenic, run into slender 
 bags in a dry state. Each bag is coiled like a snake, and tied with 
 thread. The outer end is lighted. Two coils are said to be sufficient 
 for an ordinarv room, and lOU coils sell for G cent^. 
 
51 
 
 Rmirt/iis fur h/fts. Dr. K. O. Pctk. of Mdiiislown, N. J.. \n lotc 
 to tliis otlicc hist smnnuT stji(in«:- tlint he had found l:1\ cciin a -onci- 
 eit^n I'urc for tin* l)it('s. Touch I he l)it«' with olvccriii. and in a few 
 niimitos tlio i)aln is vroxw. According- to I)r. Peek it also took the 
 pain from Ihm' stiniis. Dr. C'harh's A. Nash, of New York City, has 
 roiHMitly inforiiKHl the writer, \^\ corrcspondcnri'. thai whcnrNcr a 
 iiiosquito ])itos liini \\v rubs tiu' spot and marks it with a hunj) of 
 indioo. This, ho says, "instuntiuu'ously renders the bite absohitel}^ 
 of no aecount,'' whether the application is made immediately, the next 
 day. or the day after. He has used it since 1878, and lives in a New 
 Jersey town where, lie writes, •*mos(]uitoes are a pest every 3- ear." 
 He finds the same application to g'ive relief from the stings of the 
 yellow jacket. Household ammonia has ])een found b^^ man}' persons 
 to give relief. 
 
 DESTKUCTION OF LAKV^ AND ABOLITION OF BREEDING PLACP:S. 
 
 The following paragraphs are quoted from the writer's article in 
 Bulletin No. 1: 
 
 "Altogether the most satisfactory ways of lighting mosquitoes are 
 those which result in the destruction of the larva? or the abolition of 
 their breeding places. In not every locality are these measures feasi- 
 ble, ])ut in many places there is absoluteh^ no necessity' for the 
 mosquito annoyance. The three main preventive measures are the 
 draining of breeding places, the introduction of small tish into fishless 
 breeding places, and the treatment of such pools with kerosene. 
 These are three alternatives, any one of which will be efficacious, and 
 any one of which may be used where there are reasons against the 
 trial of the others. 
 
 ^''Kerosene on hreeding 2^ools. — In 1892 the writer pul^lished the tirst 
 account of extensive out-of-doors experiments to determine the actual 
 effect upon the mosquitoes of a thin hner of kerosene upon the sur- 
 face of water in breeding pools and the relative amount to be used. 
 He showed the quantit}' of kerosene necessar}' for a given water sur- 
 face, and demonstrated further that not only are the larva? and pupee 
 thereby destroyed almost immediately, but that the female mosquitoes 
 are not deterred from attempting to oviposit upon the surface of the 
 water, and that the}' are thus destroyed in large numbers he/ore their 
 eggs are laid. He also showed approximately the length of time for 
 which one such treatment would remain operative. No originality 
 was claimed for the suggestion, but only for the more or less exact 
 experimentation. The writer, himself, as early as 186T, had found 
 that kerosene would kill mosquito larv», and the same knowledge was 
 probably put in practice, although without publicity, in other parts of 
 the country. In fact, Mr. H. E. Weed states (Insect Life, Vol. VH, 
 
52 
 
 p. 'Ji'J) tliat ill the FiMMirli (jiiaitci- of New Orleans it has Ihmmi a coiii- 
 inoii inacticc for many years to phu*' keroseiic in tlio watiT tanks to 
 K'sscn tin- nunilM r< of inostjuitocs in a jrivrn locality, although he knew 
 n()thin«r that had hi'cn written to show that such was the eiLse, and he 
 says: 'In thisa«i^e of ad\ anci-nient we can no lonj^er tr<> by hearsay evi- 
 dence.' Suj^gestions as to the use of kerosene, and even experiiiient.s on 
 a water surface lO inches sc(uai«'. showin<r that the lai'\ le could ))e killed 
 }>y kiMosene, were recorded by Mis. ('. H, Aaron in her LanilK)rn 
 prize essay and published in the work entitled " Draj^on Flies tyersus 
 Mosijuitoes' (D. Appleton c<: (\>., 1M>0). Mi-. W. Beuteninuller. also 
 in tile same work. ina(U> tin- same su<rK^'-^tion. 
 
 ••'riic (plant ity of kerosene to })e practically used, as shown by the 
 writ<'r's experiments, is approximately 1 ounce to ir> xpiare feet of 
 wat*'r surface, and ordinarily the api)lication need not be renewed for 
 one month. Since iSDri several demonstrations, on ))oth a large and a 
 small scab', have been made. Two localities were rid of the moscjuito 
 plague under the supervision of the writer hy the use of kerosene 
 alone. Mr. Weed, in the article above mentioned, states that he rid 
 the college campus of the Mississippi Agricultural College of mos- 
 ipiitoes })y the treatment with kerosene of eleven large water tanks. 
 Dr. John B. Smith has recorded, though without deUiils, success with 
 this remedy in two cases on Long Island (Insect Life. Vol. VI, p. 91). 
 Prof. .1. II. (omstock tells the writer that a similar series of experi- 
 ments, with perfectly satisfactory results, was carried out by Mr. Ver- 
 non L. Kellogg on the campus of Stanford Universit}', at Palo Alto, 
 C'al. In this case post holes filled with surface water were treated, 
 with the result that the moscpiito plague was almost immediately 
 alleviated. 
 
 ''Additional experiments on a somewhat larger scab- have been made 
 by Rev. ,Tohn D. Long at Oak Island Beach. Long Island Sound, and 
 by ^Ir. W. K. Ilopson, near Bridgeport. Conn., also on the shores of 
 Long Island Sound, the experiments in both cases indicating the effi- 
 cacy of the remedy when applied intelligently. I have not been able 
 to learn the details of Mr. Hopson's operations, but am told that they 
 included extensive draining as well as the use of kerosene. 
 
 "It is not, however, the great sea marshes along the coast, where 
 mos(piitoes breed in countless numbers, which we can expect to treat 
 by this method, but the inkuid places, where the moscpiito supply is 
 derived from comparatively small swamps and circumscribed pools. 
 In most localities people endure the toiinent or direct their remedies 
 against the adult insect only, without the slightest attempt to investi- 
 gate the source of the supply, when tin* \ cry first stej) should be the 
 undertiiking of .such an investigation. In '(ileanings in Bee Culture' 
 (Octo})er 1. ISDo) we notice the statement in the California column 
 that in some California towns the pit or vault behind water-closets is 
 
58 
 
 subject to flusliiiiy- Nvitli water (Imiiii^- llir ii-rinat ion of llicland near!)}'. 
 A period of s(>veral wet'ks elapses before more water is luiiied in, and 
 in the meantinu* the water hcconies stagnant and the hreedin*;' phiee of 
 millions of nios(piitoes. 'Piien. as llie cori-espondent. says, 'people. oQ 
 around wondcrino- where all the inos([uitoes come from, put u]) screens, 
 biirn ])uhach, and mak(* a oivat fuss.' Nothing could ])e easier than to 
 pour an ounce of kerost^ie into eacli of these pits, and all danger fiom 
 mos(piitoes will ha\'e passed. 
 
 "In many houses in Baltimore, ^Fd.. the sewage drains lirst, into 
 W'Clls or sinks in the hack yard, and thence in some cases into sewers, 
 and in other cases is pumped out periodically. Thes«^ wells invariabl}^ 
 have open privies built over th(-m, and the moscpiitoes, Avhich ])reed in 
 the stagnant contents of the sinks, have free egress into the open air 
 back of the houses. Hence parts of Baltimore much farther removed 
 from either running or stagnant water than certain parts of Washing- 
 ton, where no mosquitoes are found, are terribly mos(|uito riddcMi, and 
 sleep without mosquito bars is, from May to December, almost impos- 
 sible. Specimens of Ciilex 2yii'n{/(nx captured November 5 in such a 
 privy as described have been brought to the writer from Baltimore b}^ 
 one of his assistants, ]Mr. E. M. Reese. 
 
 "Kerosene has been tried ])y Mr. Reese in one case in Baltimore, 
 and two treatments of a privy made about May 1 and June 1, respec- 
 tiveh^, seemed to diminish the numbers of the pest in that particular 
 house; but without concerted action of all the householders in a given 
 block (all the houses, be it remembered, being exactly alike in the 
 method of sewage disposal) no great amount of good could be accom- 
 plished. With such concerted action, however, there seems to be no 
 reason why the mosquito plague could not be greatly diminished in 
 man}", if not most, parts of Baltimore at a very small expense. Usualh' 
 one well serves two houses, the privies being built in paii-s. so that one 
 treatment would suffice for two dwellings. 
 
 On ponds of any size the quickest and most perfect method of form- 
 ing a film of kerosene will be to spray the oil over the surface of the 
 water. 
 
 ''''Drainage. — The remedy which depends upon draining T)reeding 
 places needs no extended discussion. Naturally the draining otl' of the 
 water of pools will prevent mosquitoes from breeding there, and the 
 possibility of such draining and the means by Avhich it may ])e done wdll 
 vary wdth each individual case. The writer is informed that an elabo- 
 rate bit of work which has been done at Virginia Beach bears on this 
 method. Behind the hotels at this place, the hotels themselves front- 
 ing upon the beach, was a large fresh -water lake, which, Avith its 
 adjoining swamps, was a source of mosquito supply, and it was further 
 feared that it made the neighborhood malarious. Two canals w^ere cut 
 from the lake to the ocean, and bv means of machinerv the water of the 
 
54 
 
 hiko wiu< cliaii^j'd from ji IkkIv of fresh ton Ixxly of suit wjitc/. Water 
 that is soiiu'wlijii hrackisli will support inosijuitoes, but water wliich 
 is purely salt will destroy tlieiu. 
 
 " I Practical ti.sc (tfjiah. — Thci introduetion of tisli intofishless breeding 
 ]>laces is aiiothei- inatti'r. Tt may be undesirable to treat eertain 
 breediiiL! pliices with kerosene, as. for instiuiee. water which is intended 
 lor drinkinji". althouich this has becMi don<' without harm in tunks 
 where, as is eushmiary, the drinking supply is drawn from the botU)in 
 of the tank. All interesting eas«' not«'d in Insect Life (Vol. IV, 
 p. 1^2'i). ill w liieli a })air of carp was })lace([ in «'ach of several tanks, 
 ill tli«' Ki\ ieia. is a cjisi» in point. The value of most small tishes for 
 the purpos<» of destroying mosipiito lai'vie was well indicated by an 
 t'xperience desciibed to us by Mr. (\ IT. Russell, of Bridgepcn't, Conn. 
 In this case a very high tide broke away a dike and flooded the salt 
 meadows of Stratford, a small town a few miles from Bridgeport. 
 The receding tide left two small lakes, nearly side by side and of the 
 same size. In one lake the tide left a dozen or more small tishes, 
 while the other was tishless. An examination by ^Mr. Kusscdl in the 
 summer of ISl>i show(Ml that while the tishless lake contuinecl tens of 
 thousands of mos(juito lai'Vie, that containing the.tish had no lar\;e. 
 
 " The us«M)f carp for this purpose hjis been mentioned in the pn'ceding 
 paragraph, but most small lish will answer as well. The writer knows 
 of none that will Im^ better than either of the conunon little stiekle- 
 1)acks ((r{f.sfr/'(f.sfrtfs (iruhatu-s ov Pi/(j<>sfci(s jHUKj if i u.s) . They are small, 
 but very active and very voracious. Mr. F. W. Urich, of Trinidad, 
 has written us that there is a little cyprinoid common in that island 
 which answers admirably for this purpose. This tisli has not been 
 specitically determined, but we hope to make an eti'ort to introduce it 
 into our Southern Stfites, if it proves to be new to our fauna. At Bee- 
 ville. Tex., a little fish is used for this purpose, which is there called a 
 perch, although we have not been aide to tind out just what the species 
 is. They soon <nit up the mosquito larva\ however, and in order to 
 keep them alive th<»- people adopt an ingenious flytnip, which they keep 
 in their houses and in which about a (piart of Hies a day is caught. 
 These Hies are then fed to the lish. This makes a little circle whieh 
 strikes us as particularly ingenious and ph^isant. The Hytraps cat^di 
 the flies and rid tln^ house of that pest. The flies are fed to the lish in 
 tIk* water tanks and keep tlwin alive in order that they may feed on 
 the nios(|uito lar\ ic. thus keeping the houses free of moscpiitoes. 
 
 " Arl[p('t<d (Kiiftifton of tJir irdirr. — Where kero.sene is considered 
 objectiona]»le, and where fish can not be readily obtained, there is 
 another c(»iirse left op<'n. It is the constiint artificial agitjition of the 
 water, since mosiiuitoes will oviposit only in still watei-. At San 
 Diego, Tex., in the suitumM* there are no streams for many miles, but 
 plenty of moscjuitoes l»reed in \\w water tanks. Some enterprising 
 
55 
 
 individuals kopt thoir tanks U-rv hy putliiiLj- in a lilth' wIhm'I, which is 
 turned ))y the wiiuhnill. and U('«'})s (he watn- ahnosl constjintly 
 ag-itated." 
 
 Later (it<e of I'erosenc. — Since the })u])Iicati()n of the reconunc'ndations 
 just quoted, a great deal of experimental work has heen carried on in 
 ditt'erent parts of tlie country, l)()th on a small scale and on hirge 
 scahvs. An unfortunate editorial note published in the vVmerican 
 Naturalist in ISi);') states that tlu^ writcM- discovered the kerosene treat- 
 ment aoainst moscjuito larva', whereas in liis first article on the .sub- 
 ject (Insect Life, Vol. V, pp. VI to 14) he ])eg{iii with th(^ ^vords: "One 
 of the most reasonable of the reeonuuendations w hich have been made 
 from time to time * '" '^' is the application of kerosene to restricted 
 and fishless breeding ponds.'' The note in the Naturalist was the text, 
 however, for a sarcastic note in the Revue Scientifique, 1895, Volume 
 IV, page 729, by a writer named Delbceuf , aimed not onh^ against the 
 writer, but against Americans in general. He stated that he had used 
 kerosene as a remedy for full}' fifty 3 ears, and that its use is referred 
 to in the Journal Pittoresque for 184T, page 80, where it is spoken of 
 as something already well known. Since the writer made no claims 
 to an}^ originality, but simph^ announced exact experimentation upon 
 a somewhat large scale, the matter may rest very comfortably where 
 it is. But it is interesting to note here that as long ago as 1812, in a 
 work published in London under the title "Omniana or Horse Otio- 
 siores," a collection of odds and ends of all kinds, the following sugges- 
 tion is made: 
 
 The mosquito, which is of all the race of flies the most noxious, breeds in the 
 water. Might it not be jjossible at the seasons when they emerge and when they 
 deposit their eggs upon the surface to diminish their numbers by pouring oil upon 
 great standing water and large rivers in those places which are most infested by 
 them? 
 
 The writer is indebted to Mr. D. C. Clark, of Baltimore, for this 
 interesting reference. 
 
 During the past few 3^ears kerosene has been rather extensiveh' used 
 at man}^ places in an effort to limit the mosquito supplv. As already 
 pointed out, there are many places where the source of mosquito sup- 
 ply is definitely limited and eas}^ of treatment, and in such cases on 
 account of the cheapness of kerosene it will be the best means of erad- 
 ication. In other places where communities are surrounded with 
 swamp land or in the case of extensive sea marshes kerosene can be 
 practically used in connection w^ith other and more elaborate measures, 
 comprehending, as a rule, d\^king and draining. At a relatively slight 
 expense, however, a countr}^ club on Staten Island has during one sea- 
 son practically stopped the breeding of Culex ])imgei}ii in ponds and 
 marshes in the vicinity b}^ the use of kerosene alone. This substance 
 has also been used with good effect by the Town Improvement Society 
 
56 
 
 :it Summit, N. J., in woodland pools and swamp land, and its use on a 
 Uivgv s<ah' is )M*in<; attcmpt^'d thr })n'S('nt y«*ai' in the vicinity of a arge 
 town on Long Island. Dr. A. I>. Ho})kins, of Morgantown, W. V^a., 
 tolls tho writci- that a)K)ut ten years ago an exteiLsive pumping station 
 was located near the river Iwink where the oil pipo line crosses a mile 
 above Morgantown and that the oil frecpiently escapes out over the 
 river. Since tliat time the city has ))cen almost exempt from 
 mosquitoes. 
 
 In ls:»T. Mr. .M. .1. Wightman, while interested in developing a new 
 resort known as Midland Reach, had 4 barrels of crude |M*troleum 
 scatt^Ted over the marshes surrounding the ]>each. Foi* three weeks 
 })re\ ioiLsly tln' mos(|uitoes had ])een unl)earal)le. The employees at 
 the ))«nich went aljout witli their heads covered with netting, and o^ 
 couise this had a very discouraging influence upon visitors. The 
 oiled district cover(Hl a radius of lialf a mile, and Mr. Wightman, writ- 
 ing in 1899, stated lliat within tiiree days after the oil was di.stributed 
 mo.s(juitoes were rare along the ))each. This condition lasted through- 
 out the season. Recently, owing to a change of management, the 
 writer is informed that nothing has been done and that mosquitoes 
 ha\'e l)ecome plentiful again. 
 
 Dr. St. (leorge (Jray, of St. Lucia, Britisli West Indies, writes, after 
 reading Bulletin -I of this office, that he has tried kerosene in his well 
 and in the water jars in his yard with the result that one species has 
 disappeared from his house and that the other mo.squitoes give liim 
 very little trouble. 
 
 The remedial experiments against mosquito larva^ tried by Doctors 
 Stephens and Christopher at Sierra Leone are given in the reports to 
 the malaria conuuittee of th(^ Royal Society, London. July 0, 19(X). 
 The}' selected as the most practical larvicides kerosene (paraffin oil) 
 and salt. The salt, requiring a very strong solution, was not experi- 
 mented with extensively. A few handfuls thrown into pools contain- 
 ing not more than 3 or 4 pints of water produced no effect in three 
 days. With kenxsene the rook pools and small runnells of water were 
 treated: **The larvicidal etiect in the pools was very striking, most of 
 the lan^iv being killed in fifteen minutes or less. In many cases again, 
 besides the larvicidal effect, adult females were found next day killed 
 by the paraffin on the surface of the pool where they had come. to la}' 
 their eggs.-' Thus the writer's 1893 olxservation on the non-deterrent 
 etiect of the kerosene film on adult moscjuiti^xs and their resultant 
 destruction befoi(» the eggs are laid is confirmed. This has always 
 .seemed to be a point of great pi*actical value in the use of kerosene. 
 Th<» final result by tli«^ English observers, however, was found to be the 
 immediate i-etuin of the ins(M*ts on the cessation of thi^ application of 
 petroleum. An interesting test experiuKMit was made by them ujwn a 
 surfa«e drain arising from a s])ring and rumiing for 3(K) yards when it 
 
57 
 
 ontored a ])rook. Thosprinjjf was free t'loin I:ii\a . !>iit thcdniin Iccmcd 
 with tbeiii throuohoiit its (Mitirii length. ()\rr (liis drain kci-oscnc oil 
 was spriidvUnl ])y incaiis of a watoriii^- ])()t. About 4: <»allons siilliccd to 
 cover the drain tliiekly Avitli oil. '•'riic ]ar\ icidal eliect was imme- 
 diate, and on the foUowinif" day no li\inu- lar\ je were se(»n. I'our days 
 later traees of oil were still i)res(Mit in places. Ki^lit days later small 
 larvae were present along the whole drain. " * * A weekly a})i)li- 
 cation of paraffin then would eflectually ])re^•(Mlt the foi-niation of the 
 })erfeet insect in tliese situations." 
 
 The rapid disappearance of the kerosene covering in this hist expcn-i- 
 ment is quite contrary to the results of our applications made to still 
 pools of water. This may have ])een due in part to the fact that there 
 was more or less of a current in the drain, and may also have Ix^en 
 due to the use of an especially volatile kerosene. The writer is now 
 advising- the use of the grade known as lubricating oil as the result of 
 the extensive experiments made on Staten Island. It is much more 
 persistent than the ordinar}^ illuminating oils. 
 
 An interesting plan, suggested to the writer ]>y Mr. W. C. Kerr, 
 of New York, in conversation, to disseminate oil over salt marshes, 
 was that of putting barrels of oil in the marshes in winter when the 
 ground is frozen and piercing the barrels with small holes so that the 
 oil will escape slowty through the following breeding season. The best 
 method of distributing oil on the surface of water is a practical ques- 
 tion which each experimenter is apt to settle for himself. The Avriter 
 has adopted the plan of simply pouring the requisite quantity of oil 
 upon the water and allowing it to spread by itself, which it does in the 
 course of time. The Staten Island and Summit, N. J., people use a 
 spray pump, but in some ways this seems to the writer not perfectly 
 satisfactory. A great deal of kerosene is apt to be wasted and the 
 continuous la^^er of oil which is desirable is frequenth" not brought 
 about. The Liverpool School of Tropical Diseases advises as the 
 result of the Sierra Leone work that the oil can be best applied by 
 smearing the pool with a rag iixed to the end of a stick and dipped in 
 a pot of oil. " In this manner a num})er of pools can be dealt with in 
 five minutes at the expense of ver}' little oil." 
 
 OTHER LARVICIDES. 
 
 Permanganate of potash. — Other su])stances have been experimented 
 with. Two 3^ears ago many newspapers contained an item concerning 
 the use of permanganate of potash. As this item was credited to the 
 Public Health Journal it gained a great deal of credence, and was 
 afterwards mentioned in an interesting article by Mr. A. C. Weeks, 
 in the Scientific American. The published note read as follows: 
 
 Two and one-half hours are required for a mosquito to develop from its first stage, 
 a speck resembling cholera bacteria, to its active and venomous maturity. The 
 
58 
 
 instMt ill all its iiha.<**s may Ik* iiiHtantly kill(*<l l»y conta*-! with ininuto quantitieH of 
 l»c*rnianj:aiuitr »if itnta^^li. It is tlaiiind that 1 j»art of this Huht>taiK'e in 1,500 of 
 .solution (listrihutrd in niof^juito niarslu'H will iviuler the development of larvt-e 
 inii>ossihK'; that a haiulfnl of pernian^anat** will oxidize a 10-aere Hwainp, kill itn 
 eiiiliryo innet-tM, and keep it free from or^'anic matter for thirty <layH, at a cost of 25 
 r-ent^; that with care a whole State may he kept free of insect j»ests at a small cost. 
 An iHicaci«»ns method is to scatter a few <Tystals widely apart. A sin^de pinch of 
 peniian^Miiatc has killed all the;:erms in a 1 ,(KM)-.jallon tank. 
 
 The item is so ()li\i()iisly fidiciilous upon its fac*' tlnit it would liiirdly 
 seem woitli Nvliih' to make any attemp. to i-efiile its statements. Nev- 
 (Ttht le>s. it has heen so \vi(l(dy read thai dcdiiiite e.xpeiimentation 
 seems neci'ssary to set the matter at I'est. The unknown author's 
 iotioraneo of the life histoiy of moscjuitoes in the oi)ernno- sentence 
 need not necessarily imply that he would not know a j_^ood femedv if 
 lie found one. ( ai'cfid experiments ^vcl•^^ imdertaken hy the wfiter 
 in July. iStKS, with various strenoths of peiinanjj;anat4' of i)ot{tsh in 
 water containino- moscpiito lai\ u' froiu one to six days old. It was 
 foimd that small amounts of the chemical liad no efl'ect whatever u])on 
 the laixa'. which were, however, killed ]>y usino- amounts so hirge that, 
 iust^'ad of using a ''handful to a lo-acre swamp/' at least a waj^on 
 load woidd have U) ]h\ used to accomplish any result. Moreover, after 
 th(^ use of this large amount and after the larvni were killed, the same 
 water twenty -four hours later, sustained freshly-hat<*hed mosquito 
 larva? perfectly, so that (»ven were a person to go to the prohibitive 
 expens(» of killing moscjuito larvte in the swamp with permanganate 
 of potash, th(i same tusk would have to be done over again two days 
 later. 
 
 The same conclusion was sul)se(juently reached, after careful experi- 
 ment, 1)V Dr. Lederle, of the New York health olHce, and ))y the Ital- 
 ians (\dli and Casagran<li. 
 
 I^ropr'nidni '^mlxtinus. — A munber of proprietary and secret mix- 
 tures rcH'onuniMuled for m()S(iuit()-l)ree(ling pools and whi(di have been 
 ])ut on the market since tin* vvide-spread interest in the moscpiito ques- 
 tion has spnuig up ha\ c beiMi tested bv the writiM', Init none have been 
 found more satisfactory than the cheapest jxdroleum oil. 
 
 Krjx I'fiiKiifx of ( 'rll/ tiiid ( 'iixiKji'dniVt. The most extensive s(n*ies of 
 expeiinsents with culicidal mixtures which has been made was con- 
 ducted by the lt;dians (\dli and Casagrandi, above* referred to. They 
 lia\'e ta))ulate(l in tlu' "Annali d' Igiene Sperimentale. Ivome (\'(d. IX. 
 Fasc. Ill, lsi)l>, ])p. :il7-:)r):)), the results of exi)eriments with many 
 >ul>stances. Ueferring to petroleiuu, th(\v say that apart from the 
 (piestion of \X\(\ expense, which outside (d' AmtM'ica is worthy of note, 
 the action of })etroleinn in destroying mosipnto larvie is not always to 
 be put in the front rank. Their con(dusions ar«' practically as follows: 
 
 (1) of tlu' whole jicriod of the cycle of development of mos(|nit<K's the stagers in 
 whicli they are most easily di'stroyed are th(>si' of larva' and of iln- aerial iiios«piito, 
 
 and larv.e are most eavi|\- killed iju' \..iui<_'ei- tlie\ are. 
 
59 
 
 (2) To kill tlu' larva', amon«; imiiu'ntus .Muh.Mtancos oxiM^riinontc<l \\illi, Ihtn- will 
 nave, ill iUHR'a>iin«; «)r(UT, culiriilal action: (a) Mineral: Hiilphuroiis (»xi<i»', jKrinan- 
 j;anate of i)otash with hydrochloric acid, coimnoii Siilt, iK)tii.sh, aninionia, carburet of 
 lime, eorrosive sublimate, chloride of lime, tlu' bisuli)hites, Hiilpliat*^ of iron or cop- 
 per, lime, bichromate of potiish, and sodium sulphit*'. (b) Orj^anic: i»(^vders of the 
 unexpanded flowers of ('hrysanthemiim, tobacco, ix'troleum and oils, formalin, 
 creso., certain aniline colors («rallot, «rreen malachite), coal tar. Taking into account, 
 however, the (h^-^e necessary to kill the larva', the ])racticability and the ]»rice, all of 
 the mineral and some of the organic substances are excluded, and there remain as 
 available the vegetable ])owders, petroleum, and the aniline colors. 
 
 (3) To kill aerial mosquitoes, we have odors, fumes, or gjuses. Among the odors 
 are turpentine, iodoform, menthol, nutmeg, camphor, garlic. Among the fumeft 
 are tobacco, chrysanthemum powder, fresh leaves of eucalyptus, qua.ssia wood, 
 pyrethrum powder. Among the gases, sulphuric oxide. It is, however, to he noted 
 that for these odors, fumes, or ga.ses to exercise their culicidal action they must fill 
 or saturate the whole ambient; otherwise they produce only apparent death, or at 
 most only a culicifugal action, which sometimes in houses may be useful in protect- 
 ing man from being bitten by mosquitoes, and preventing the latter infecting him 
 when they have sucked the blood of malarious persons. 
 
 (4) The problem of the destruction of mosquitoes is experimentally soluble, but 
 practically it will only be so when economic interests desire it. In this latter sense 
 it is remarkable that the old larvicidal use of petroleum has not become much diffused 
 in those places where it is very cheap. The chrysanthemum plants might l)e grown 
 on a large scale, this making the malarial place itself produce that substance Avhich 
 frees it of the mosquitoes that infest it. 
 
 (5) The opportune season for killing the larvae is in the winter, when they are in 
 least numbers in the waters and new generations are not born; this also is the season 
 for their destruction in houses, for they come here for a warmer abode. Their habits 
 and places of nesting should be studied to this end. This may not be accomplished 
 on a large scale as easily as some boast; nevertheless, after the treasures spent by 
 nations and individuals for preserving vines and vegetation from the oidium, the 
 }ieronospora, and the phylloxera, we may hoj^e that something may be done for 
 protecting the life of man from the mosquitoes of malaria. 
 
 It will be noticed that they really exclude from further consideration 
 all substances except vegetable powders, petroleum, and the aniline 
 colors. By vegetable powders they refer to the powders from the 
 flowers of plants of the genus Pyrethrum, and their experiments upon 
 the aniline colors practically center upon the recommendation of the 
 substance already referred to as the yellow aniline dye which the}' call 
 '• Lar3'cith TIT." This color has the property of other aniline colors in 
 that it is soluble and diffusible in water. The practice recommended 
 is to make a concentrated solution, which is poured into the pool or 
 pond to be treated. Tt is said l\v the authors that it will destroy all 
 insect life and fishes, but is harmless to warm-])looded animals: thus 
 domestic animals may, without danger, driniv from pools being treated. 
 
 Just what "Larycith III" will prove to be and whether it will be 
 available for use in this countr}^ unfortunately can not be ascertained 
 at the present moment. Correspondence has been entered into with 
 large dye firms in New York Avho have sent abroad for information. 
 
 Dr. Ross, in his article in Nature of March 29, previously referred 
 
60 
 
 to, says: ''On the whole, the most proniisint^ method which suggests 
 itself is the ein])l<>vin('nt of some cheap solid material or ])owder which 
 dissolves slowly, which kills the larva' without iiijurini^- higher animals, 
 and which rend«'rs small })()ols uniidiabitahle for the larva? for some 
 months. \(^ for instance, a cartload of such material would suffice 
 to e\tirpat«' the larvae over a square mile of a malarious town, the 
 ic^nh would Itc :i large gain to its healthfulness. Dr. Fitdding-Ould 
 has lately reported favorably on tar.'' 
 
 ////' <f/t(/ /As' r(///tj)ot/n<7.s. -Again, in the re|)ort of the Liverpool 
 School of Tropical Diseases the following woi'ds occur: *' Perhaps more 
 permanent oil than UcM'osene would he more p<'iinanently j'tt'ective. 
 Fi-esh tar dro})ped in a puddle makes a film like that of oil and lias 
 heen faNorahly i-eported on. (Quicklime has been suggested, and all 
 these should certainly he tried.'' 
 
 The writer is i-ather at a loss to know exactly what is meant )jy the 
 expressions '* fresh tar" and "tai** in the above paragraphs. He has 
 conducted an exp<'riment, however, with a substance known to the 
 trade as ''coal tar,'' a thick viscid liquid. A few large drops of this 
 substance AvcM'e dropped into a glass vessel containing approximately 
 2 (juarts of water in which were mort^ than 1(K> full-gi*own larva' of 
 Culex. All the drops but one sank at once to the bottom, the last one 
 floating upon the surface for some time. No surface film seemed to 
 form from the tar. but after the expiration of forty-eight houi's the 
 water was found. to be more oi- less impi'egnated by the tar, having 
 turned somewhat darkei- ill color, while the odor of the tar was per- 
 eeptible. At the expiration of live days nearly all the Culex larva^ 
 were dead; 1 had succeeded in transformuig to ])upa, and 5 or (\ remained 
 at the surface enfeelded and dying. Thus more than IC) per cent had 
 been killed. In the meantime, howex cr, twenty-four hours after the 
 experiment began. >> (\gg mass(\s wer«^ laid on the surface of the water 
 by outside females of Tulex. These had hatched in forty-eight hours 
 more, and on the Hfth day. altiiough the original fuU-gi'own lai'va' 
 were ])ractically exterminated, many young larva' were swarming 
 activ<'ly about in th<' tar watei". They continued to grow and to 
 remain a})})arently ])ei-fectly active and healthy, although the odor of 
 the tar was distinctly ])erceptible and the color of the watei* was dark, 
 and cNcn a thin oily lilni remained o\'er a portion of the sui'face. 
 
 From this expeiiment it was plain that the killing effect of the tar 
 in the ])i-e})aration used is comparatively fugitive, and it was next 
 decided to test some of the coal-tar products. The object of this line 
 of experimentation w.is not oidy to test the suggestions of the English 
 ()})servers, but also on account of the fact that as almost eveiy com- 
 nnmity manufactures its own illuminating gas it was considered an 
 easy and ]irobably econominal way of securing a mosquito larvicide, if 
 it should pro\ e to be ell'ecti\ e. Coal tai" is distilled into various gmdes 
 
61 
 
 of oil, jiiul two of the licMvicr of tlicst* o-mdcs W(»n», used in tin* sin*- 
 c'(HMliiiu- cxjH'rinuMits. One of tlicso was cjilicd ••creosote oil," and was 
 }i ratlu'i' liiilil oil of a sjn'cilic ^raxil y of LO^f) at <i(>" l'\. and the oilier, 
 beaiini:- no name, was somewhat lieaxier. Tlie e\i)eriiiients wc^re nec- 
 essarily on a somewhat small scale. Kiyhty nearly fidl-iirown lar\;L' 
 of C>i/('.i' sf fill ii/dii-s and (\ 2>( /•/ ui'lnms were placed in '.\ (|narts of water 
 and one-fourth oimc(» of creosote oil was poured in at 4.1;") p. m. At 
 5.45 IT i)U})a' and 'r, ljirv;e wei'e left ali\'e. The next mornino- at \) 
 o'clock it was found that S adults had issued oN'cr nij^'ht, ])ut all had 
 been killed ])y the creosote. At )) }). m. of the same day. twiMity-threc 
 hours after tlu' introduction of the insecticid(% all larva' and pupa; were 
 dead. With the slightly heavier oil. 150 lar\ ;e of the same species, 
 all full grown or nearly so, were placed in '1 (piarts of water and three- 
 sixteenths ounce of the oil was added at 4.15 p. m. At 5.45 all were 
 dead except i^8 pupa? and about 30 larvae The next morning* at 9 
 o'clock it was discovered that 10 {idults had issucnl ovcm* night, but had 
 been killed before flight b}^ the oil. At 4.30 p. m. of the same day all 
 the larvae were dead, but 10 pupte w ere still active. On the following 
 morning, at D o'clock, forty-two hours after the ai)plication, all larvae 
 were dead and the adults had issued from the remaining pup^e, but 
 had been caught bv the oily him in the act of issuing and had died 
 upon the surface of the water. 
 
 Still another experiment was tried with pupae only. Two hundred 
 and fifty pupae of the same Culices were placed in 3 (piarts of water 
 and one-fourth ounce of creosote oil was added. Twenty hours later 
 many of the pupae were still living, but thirty^-six hours from the time 
 of application all Avere dead, no adults having issued. A check experi- 
 ment with kerosene was carried on parallel with this last experiment 
 with creosote, a*nd it was noticed that the action of the kerosene upon 
 the pupae was much quicker, all dying within forty-five minutes. A 
 few young larvae, however, in the same jar lived for several hours. 
 
 An interesting efiect of the application of the creosote in the first 
 two of these experiments was that it seemed without doubt to hasten 
 the transformation of the insect. When at 4.15 the creosote was 
 poured in jars 1 and 2, no pupae were observed, but all larvae were 
 full grown or nearly so. After fifteen minutes 10 pupie were observed 
 in jar 2 and 5 in jar 1. Ten minutes later 15 were counted in jar 2 
 and 13 in jar 1. Twenty minutes later there w^ere 10 in jar 2 and 22 
 in jar 1. Fifteen minutes later still there were 19 in jar 2 and 22 in 
 jar 1. Thirty minutes later there were 17 in jar 2 (2 having died in 
 the interval) and 28 in jar 1. As above stated, over night a rumiber 
 of adults issued, 10 in jar 1 and 8 in jar 2, and twenty-four hours later 
 10 more adults issued in jar 1. It must be remarked that the full- 
 grown larv» struggled violently on perceiving the uncomfortable 
 presence of the creosote, and as they were just ready to transform this 
 
f^2 
 
 \i(»lt'iit stiiij^'-^^linj,'" j'vidnitly jissisl«'(l in (lie ]n<*akin;jf of tlio hirvjil skin, 
 h'a\ ill*,'" tlir pupa han*. This traiisforiiiation from larva to j)uj)a is 
 liai'dly as inti'restinj^" as tlir lapid (l«'\ clopnn'iit of adults, IS of which 
 IssuimI within JiftiMMi hours after tiaiisforiuation to pupa, whereas 
 prcN iously tin' shoitcst duiatioii of the pupal state whieh we had 
 ohsrrvcd was forty-cii^ht hours. It looks like an effort of Fiature to 
 j)rrp«'tuate the species in the presence of a uni(jue enicrtrency. 
 
 On the whole, the result of the experiments with tur and tar oils wa.s 
 ratln'r unsatisfactory as compared with the heavier grades of kerosene. 
 'I'he etlect of the tar was not i)ermanent, and the effect of the ere()S(>te 
 oils was not as rapid as tliat of kerosene, and the writer is inclined to 
 tlu' opinion that the heavier grades of kerosene oils are, on the whole, 
 preferable, althougli the effect of the creosote oils is very good, and 
 they can ])e used to advantage. lie is inclined to think that they may 
 })rovc to be more permanent, although not quite so rapid in their 
 effect, than the lightei* illuminating oils. 
 
 EUCALYPTUS TREES. 
 
 M a(i 
 
 Idition to the use of eucalyj)tus oil on the skin to keep mosquitoes 
 from )»iting, the growth of eucalyptus trees is said hy certain persons 
 to drive mosquitoes away, and trees of the genus Eucalyptus have 
 been especially recommended for planting in malarial regions. Mr. 
 Alvah A. Eaton, of California, wrote us in ISiKS that in portions of 
 California where the ])lue gum occurs no other remedy need ))e sought 
 for. Further than that, he stated that no matter how phMitif ul the mos- 
 quitoes, a few twigs or leaves laid on the pillow at night would secure 
 perfect inmninity. The same 3'ear Mr. W. A. Sanders, of California, 
 sent the following interesting account of the value of eucalyptus trees 
 in answer to our ]>u])lished request in Insect Life: 
 
 1 have the larjre.^t and oldest grove of trees of J'Jvcabjpfuff glolnthis in this part of 
 C'ahfornia, and liave liad fifteen years of opportunity to study these trees a>^ insect 
 repellantt<, and deem it my duty t«» respond to your request on pt^e 268 of Insect 
 Life. 
 
 Thirly-tiiree years a<ro T spent a i)ortion of one summer with a l>r. MeConnell, who 
 had just returned from some years of residence among the Eucalyptus forests of Aus- 
 tralia. We were in the Seipioia [SeijuoUi xeiupcrvlrens) forest of the coast region of 
 our State. The mwsciuitoes wi»re so bad that it was nearly impossible to work during 
 days when there was no wind. The doctor assured me that our connnon mos<]uito 
 was never found in tlie Australian Eucalyptus forests and swamj^s, but added, There's 
 a "spotted mosquito" nearly as bad there in some places. He, not l>eing an entomolo- 
 gist, was unable to tell me whether the "spotted mosquito" was a species of the 
 genus Culex, or of some allied genus. 
 
 The doctor l)eing a reliable, close ol)server, I determined to test the antimosquito 
 qualities of the Eucalyptus; so when I U'gan to improve my house here nineteen 
 years ago, one of the first thintrs I did wa.>^ to get a lot of eucalyptus seed from Aus- 
 tralia and plant out a grove oi the trees. The tallest of them are now over 140 feet 
 tall, and can be seen for 20 miles around. My house stands in the midst of these 
 
88 
 
 ttvos. ^\y irri<;atiiiir (lilcli, a du/cn \rv{ uiWc, of .sliiir^ri,v|, ,-iiiiriil, runs llnoii^'li tlift 
 jj:r()Vt> iH'sidc tlu' lioiisc. 'I'licrr li:is lu-vcr ;i silij^h' iiiostjiiito l;irv:i l«-cii hmii in tlie 
 ditch from whore it I'litt-rs the lirst shadr of these trees to where it eiiierj,M's from them 
 200 yards away, whiK' ahove and helow mos(|iiito larva- are itleiitiful— not imme- 
 diately behnv, hut some hmitheds of yards away, where the water stands in pools 
 and beeomes siai^nant amon*; a irrowth of black walnuts and cottonwoods. 
 
 My live st(X'k pasture in this tiud)er, ^'oin^' into tlie walnuts and back again under 
 the eucalyi)tus shade at pleasure. Fre(|uently w hen the c<»ws come up at night they 
 bring a swat'ui of mos(|uitoes; occasionally some of them get into the house, but 
 cause us so little auiioyanct' that we scarcely notice them. Uefoic this ditch n-aches 
 the pAicaiypti it runs through a jungle of "fence bamboo" { Arninh, ui<icri>/)lii///a), 
 where the mosijuitoes are so bad that we avoid working tiiere except on the windiest 
 days. And, though the ditch has more current there, the larva; of mosciuitoes are 
 I)leiitiful ill the water till it reaches the Kucaly])tus trec^s, below which ])oint none 
 are found till it has become stagnant away below them. 
 
 People who have camped along the willows of Kings liiver, only a few miles 
 away, have come here ^ith faces so blotched and swollen from nios(iuito bites as to 
 be hardly recognizable, and have camped in the shade of "Sanders's gum trees," as 
 my grove is popularly called, for weeks, and declare that they never even heard a 
 mosquito sing during that time. 
 
 To the non-botiinical reader I may say that this species of Eucalyptus is very tender 
 to frost. The coldest weatlier ever known here, 19° F. above zero, killed thousands 
 of them. 
 
 Dr. Nuttall points out that the phuiting ot eiicalyptu.s treefs is not a 
 sovereign remedy, from the fact that malaria still prevails at Tre 
 Fontane, outside of Rome, in spite of Eucalyptus plantings. The 
 mere planting of trees, however, is undoubtedly of use in malarial 
 districts, since it will modify the condition of drainage of the soil. 
 In view of Mr. Sanders's strong evidence it really appears that plant- 
 ing of eucalyptus trees will be worth while in certain locations, not 
 entirely (on account of the conflicting and not thoroughly satisfactory^ 
 evidence) for mosquito protection, but incidentally for this use as well 
 as other purposes. 
 
 DRAINAGE AND COMMUNITY AVORK. 
 
 After all, the best of the means which may })e adopted against mos- 
 quitoes will always consist in the abolition of their breeding places. 
 Small pools with stagnant water can be treated, but it is a great deal 
 better to drain them or to till them up. Swamp areas nmst sooner or 
 later be drained. It is perfectly obvious that the sooner this is done 
 the better from every point of view, not only from that of human 
 health but from the increased value of real estate in the neighborhood 
 and from the practical value of the reclaimed land itself. The time is 
 coming, aiKl rapidly, when this drainage of large swamps will not 
 remain a matter which concerns the individual owner of the land, but 
 one for town or county action, and even for States. The report of 
 T. J. Gardner on the policy of the State respecting drainage of large 
 swamps, published in the Report of the Board of Health for New York, 
 
64 
 
 Alljjmy, l.^^^^, alth<ni<rli uiitcdatiiijr the n'cciit iiii|M)rtiiiit in()s«jiiit() dis- 
 i-o\('i'i('s, is well \V()i-tli n-adiii*^ l»y all piihlir-niiiKlcd persons, and tin 
 annual rrports of tin- St:itt' »;«M>l()irist of New Jersey for 1M«T and ISIKS, 
 in whicli the rrclamation of the threat I laekensiu-k Meadows, near Jersey 
 City, Newark, and Klizal)etli, N. J., makes interesting^ readin*:; alon*^ 
 this lin«'. \\\»rk on tin'se marshes has actually been l)eg"un. The 
 solution of this case is takinj^the £orm of separate action hy cities and 
 their municipalities, each impro\ inu- the territory within it.s corporate 
 limits. riu' city <d' Newark has a tract of 4. ♦'»(»<» a<-res of marsh within 
 its limits: deisey C'ity has within its limits '2J)Si\ acres of tide marsh, 
 and Elizaheth has -JJuiS acres. The three cities, therefore, have about 
 8,T<M> acres of the :i7,<MM> acres lying- between Eliza}>eth and Haeken- 
 sack. 'I'he sanitaiy imi)ortance of ie<laiming these lands is of the 
 cfreatest, but the capal)ilities of th<' imprc^vement plans are attractinj^ 
 attention on the ])art of capitalists and business men, who see in these 
 tide hinds \aluable sit<'s for manufacturing, industrial, and commercial 
 activity. 
 
 Even to indi\i(lual land owners of a comnjunity, the drainage of 
 swamps and the conse(iuent abolition of mos([uitoes will in many cases 
 iKH'ome well worth while. The writer knows of a town in New Jersey, 
 with a good elevation, within easy distance of New York, and admirably 
 adapted forsununer residences of New Yorkers, where the mosquitoes 
 are so a))undant as to prevent the rise in the price of real estate. An 
 examination of the surrounding country has convinced him that if the 
 large real estiite owners were to clidj togi'ther they might, by the 
 exp(MKlitur(^ of a few thousand dollars, largely do away with the mos- 
 (juito plague. Another case which is well worth s|X}citic mention, and 
 the truth of which the writer will vouch for, may best be told in the 
 words of a correspondent, printed in one of the Flushing papers late 
 in ^larch: 
 
 In the town of Stratford, Conn., where I liave resi(le<l for the \ydsx forty-tive years, 
 we have ])een greatly i>lagiied hy swarms of niosciuitoes, so great, in fa<.'t, that the 
 "Stratford nios<]iiito" l)ecanie a well-known eharaeteristic of Stratfoni. We have in 
 the southern part of our town, liordering on .the sound, several acres of marsh land 
 or mea<low, which w<juld become i>eri(xlically overliowe<l with water in the summer 
 and a tremendoiLs bree<iing ground for mo8(]uitoes, and thiis plague to the town con- 
 tinue<l until about l800-i>l, when a party from Bridgeixjrt, Conn., purchased a large 
 section of the meadows and l>egan to j)roteot them l>y a dike, lx)th on the nc^rth and 
 south ends, which shut out the water. In addition tn this, numerous drain <iitches 
 were made, which helped to carry the water away. The result of this work made 
 the land i>erlectly <iry and spongy, so that after a rain no pools collecte<i on the sur- 
 face of the meadow an<l prevente<i the creation of the mostiuitoes. The transfonna- 
 tion wa« so remarkable that i>eople outside the town would hardly T)elieve that it 
 had iM^en effecte<l, and a year or two hiter the town vote<l a si>ecial appropriation oi 
 $2, ()()() to tlie party who undertook to huild the dike and ren<ler the meadows nios- 
 <|uito proof. It had also the effect of placing on the market a large tract of land 
 elevated from the sound for reisideuces, and as manv its 25 summer reisideuces have 
 
(if) 
 
 been built upon this land hoidcriiiL: the houihI, hihI an- iiuTcaxiiijr ra<li year. 'I'licy 
 are free from nios(iuit()('s,H) that tin- operation sbuws tin- ri-onoiuy aii<l llif Ix-nclit 
 that will result ])y usin<r soiui' mraus for flirninatin;; tlu- nios<iuito-l)n'*'(liiiK pools. 
 
 As to coinniuiiity work, we must not fail to niontion tho iiitcn'stiiif^ 
 fact that the city of Winchester, Va., is reported to liave passed an ordi- 
 nance reciuirino- property hoUhM's to treat drains and stut^Tiant pools of 
 water witli kerosene diirino- tiie siinnner season. Winchester is a town 
 of high elevation and has for a long time enjoyed a reputation among 
 Virginians as a cool place to spend the summer. Mos(piito(\s, we are 
 told, however, made their appearance there a few years ago, with the 
 effect that simimer visitors became fewer and fewer. The passing of 
 the cit}^ ordinance was deemed a matter of public policy and met Avith 
 general approval. Police measures of this kind may not be inadvis- 
 able under certain circimistances. Surely in such instances as the 
 Baltimore case, mentioned in previous pages, it seems entirely appro- 
 priate that the board of health should be called upon to enforce kero- 
 sene treatment. 
 3949 5 
 
APPENDIX. 
 
 AN KAHI.IKK ACCOl'NT <>F HIK I.AKVA OF ANOPHELES. 
 
 Just as this lujiimscript was about to he sent to the print/or the 
 writer's attention was called to a pajHT })y F. Meinert, entitled *'Die 
 encephale My»r<'lai"\ cr" (Sui' les larves encephales des Oipteres; leurs 
 UKeurs et leurs inetanioi piloses), K. l>anske Videnskabernes S<dskal)s 
 Skrifter ((\)penhatrcn), iii. pp. H7:^-lim, IMs. I-IV (l<SS(j), in which. 
 anioriiT other ohservations, he ji^ives a ln'ief stat<'iiient concerninjj^ Ano. 
 p}i«'lc> w hicli is sufficiently int4»resting to translate: 
 
 " AnnpJirli's. — In the •Observations d'Histoire Naturelle' of Joblot 
 one tinds a de.scrii)tion of this larva. *' Description of a new tish.'' 
 which is rather insignificant, and a drawinj^^ which is not badly done. 
 The larva drawn by Brauer as Anopheles is a larva of Dixa, and those 
 reported )>y Fischer (rWaldheini as (\ rhirf(j< r wrv lar\a* and nymphs 
 of the genus Corethra, while his nymph is a Tanypus. and his tiy an 
 Ano})heles. Aside from this, (ierkc has ))ri«'tly mentioned this hirva 
 in his papi'r entitled 'On the metamorphoses of the dipterous genus 
 Dixa,' page 166. 
 
 •'The larva of Ano])heles lives in still waters oi- in a weak current 
 with a rich vegetation, in wooded or unwooded regions. It does not 
 like the shade of great trees, but seeks the sun and the light, as is 
 indicated })y its fresh green color. Tt does not hibernate, but in mild 
 seasons it is found in a half-grown condition by the end of March. In 
 July or a little latter in the course of a summer the second generation 
 of the full-grown larva' are found, and in 1SS2, a year when the* spring 
 was very forward, the writer found at the end of October small larvte 
 which certaiidy belonged to the third generation; but it was not to be 
 supposed that these larvsv Avould beccmie full grown, since as they live 
 at the surface of the water the tirst film of ice would kill them. 
 
 "The larvjv hold themselves at the surface of the water, where they 
 float with the extremity of the abdomen turned toward the bank or 
 toward the plants which cover the surface. The larva is stretched out 
 in the water with the respiratory tube at the surface. The larger })art 
 of the alnlomen and posterior part of the thorax are submerged, only 
 a little portion of the prothorax emerging. The head is under water. 
 The long hairs with which {\w ))ody of the female is provided on the 
 sides, on the metathorax. and the tirst three segnuMits of the abdomen 
 are of great assistance to it in maintaining a fixed i)ositiofi. It rests 
 often for a long time immovable and oidy occasionally changes its 
 location. Its mo\ (Miients denote a certam apathy or indolence, but at 
 the same tinu^ nuuh prudence aiid apprehension. WinMi it moves it 
 
67 
 
 movos rapidly and dives to tho bottom of tho wator. Rccovcrinii from 
 its fritifht, it risos obliquoly to the surfaee. 
 
 "Just as with the lar\;e of Culcw, the, lar\a' of AMoi)h('l('s li\ <• ii|>oii 
 orgaiiie microseopie particles wliicli Hoat upon the water, and which are 
 brought into the mouth by the moN'ements of the rotatory oryfans. 
 These organs are nuich mon^ deyeloped tlian with th(^ larya' of Culex, 
 and while they serye, like the former, as a brush or sieve to strain th(^ir 
 food the larva^ of Anopheles, like those of Siimdium, holdino- the head 
 stretched forward, use them to agitate th(^ water. The larvii? of 
 Anoi)heles present this peculiarity, that in producing these currents, 
 which they do th(^ greater part of the day, they lie upon the belly 
 with the under pai't of the head turned upward. This rotation of the 
 head is executed with thegrinitest rapidity: and scarceh^, for example, 
 have the larva> come to the surface to float, when, b}^ a rotation of the 
 head upon its longitudinal axis, it is turned bottom side upward and 
 commences to agitate the surface of the water. This agitation is 
 undou])tedh" for the purpose of drawing floating oV)jects surely and 
 completely into the orifice of the mouth. This, however, is not neces- 
 sar}', for often one sees the larva with its head working in normal 
 position, mouth organs ])elow, but in general they do not remain in 
 this position for a long time, and it is only after having turned the 
 head upward that the}^ seem to work con amove. 
 
 '"As a rule the larvae seek their nourishment while they are floating 
 at the surface, but at other times they descend two or three inches 
 under the water. They can rest several minutes in this position with 
 the head below, after which they come to the surface again." 
 
 This account shows that ]Meinert knew the larva? very well, and one 
 can only regret that he did not describe the eggs and the pupae. 
 
 THE MALARIAL EXPEDITION OF THE LIVERPOOL SCHOOL OF TROPICAL 
 
 MEDICINE. 
 
 This interesting and most valuable report was known to the writer 
 only by brief newspaper notes until the present bulletin had reached 
 page proof — too late to insert in proper place several important obser- 
 vations made b}^ Ross, Annett, Austen, and Fielding-Ould. To-day 
 (August 13) it has reached him in Volume II of the Thompson Yates 
 Laboratory Reports (University Press of Liverpool, 1900), and he is 
 glad of the opportunity to add the following paragraphs quoted from 
 its pages: 
 
 8. METHODS FOR ASCERTAINING DEFINITIVE HOSTS. 
 
 The long researches of one of us in India, followed by those of Koch, Daniels, and 
 the Italian investigators, have given us a very exact knowledge of the life history of 
 the Hsemama^bidse in gnats, and have shown us how to detect them in the insects 
 with ease and certainty. It has been noted that in inhospitable species of gnats the 
 ingested parasites perish within the stomach cavity, whereas in hospitable species 
 the zygotes escape from that cavity and develop in the tissues, ultimately giving rise 
 to blasts which are found in the juices and salivary glands of the insect. * * * 
 
68 
 
 15. BIONOMK-S «tK ANOPHELES LARVJ?:. 
 
 We ma<U« the fulli.wiii^' nhservatioiiH: 
 
 (1) K(j(f}<.--T\\vrn- AW It^Htl-xfuijHfl, Vikeiho^ i){ Atwph4'h>nAy»(}r\e<\ in India. They 
 rtpjH'ar to U* laid sinjjly uii water, hut eohere hy tlieir eixls. forming typieal triangu- 
 hir j>atterns, and aln* atlhere to floating ohjeet.**, the nideK of the vessel, etc. We 
 ohnervtMl no factH imlieating that they are ever laid on wjlid purfaee**. In vitro they 
 take alMiut twenty-four hours to hatch, l>ut the iK'ri(Ml is |>rohahly nuich s}njrter in 
 l.uddles. 
 
 (2) Ihiralinii uf hinol Miujt . — Thi.s dejtends on tenifKirature an«l auHHUit of fiMwi. 
 Under natural conditions it may prohahly U' only three or four days, hut underunfa- 
 vonilde conditions (cold, overcrow* ling, ahsence <»f focwl) it may certainly extend to 
 Weeks.' Tlu-re are reasons for thinking that development is much luLstene*! hy 
 bright weather, in «.rd<'r to »'nal)l»' tin- iinag(. to hatch out In-fon* desiccation of the 
 containing )>udille. 
 
 (3) IumkJ. — The larvji- were fre<iuently watclu'<l floating on the surface and feeding 
 on filaments of waterwee*!, amongst which they often entangle themselves. On dis- 
 section the intestine was found crammed with these filaments. It wa.s ohserve<l that 
 JM vitrit the larva' scarcely grow in size unless they are given large cjuantities of water- 
 wee<l, which they <lispose of very rapidly. On the other hand, larvte were often 
 cauglit in puddles in which no green vegetation could }>e seen. They may eat other 
 fo(Ml, l)ut it would seem as if waterwee<ls constitute their favorite diet. It was also 
 note<l that they obtain shelter among these wee<ls from the current running through 
 the j>ools during or after rain. 
 
 (4) Enemies. — No oV>servations could l»e made under this head, Init we often found 
 many frogs and tadpoles in the ]>reeding ]»ools. apparently living at jK^ace with the 
 larvae. 
 
 (5) Effects of desiccation. — During most of our stay in Freetown lieavy showers fell 
 several times a day, so that the larvje couM live secure from desiccation in all but 
 the most evanescent puddles. In September, however, there was a complete break 
 in the rains, lasting three days. A lai-ge num])er of the pools, even many of those 
 containing waterwee<l, and those fed by sjjrings during rain, dried up completely. 
 The question whether the larva* had the jMiwer of living in the nnid at the bottom of 
 the jM>ols couM now Ik^ teste<l by direct observation. The bri'ak in the rains was 
 followtMl by heavy showers, which immediately refille<l all the puddles. Hail the 
 larva' contimied to exist in the mud, they would now have emerge<l again. As 
 regards the pud<lles in which the mud had completely drie<l, this wa.s not the c^ase. 
 No larvje at all were f()und in them for at least two days after the rain had refilled 
 them. After that interval larva- again apj>eared, ]>ut they were very small ones, 
 evidently just hatched from the egg. On the other hand, it wiu< frequently 
 observe<l that if the mud di<l not l>ecome completely dry, the larva* would emerge 
 into active existence after another shower. These observations were supportiil by 
 some exjxiriments in vitro, an«l we therefore conclude that the larva* can withstand 
 partial, though not complete, desiccation. - 
 
 (6) The same jtuddh's roihstinifh/ ornipicd. — We liave suggestetl (paragraph 13) that 
 the j>osition of the breeding j)ools may change acconling to the seasons, but while we 
 were in Frt*etown there was no change of season, and we generally found Aiiopheles 
 larva* in the sann* jiuddle, nanu*ly, in those which were suital>le for them. Thus, of 
 two jaiddles lying clo.^e together, one Mould never contain larva* and the other 
 would always contain them. The exi)lanation of this probably is that the larva* 
 
 * One of us kept Culex lar\'}e alive ft>r two months in a Inittle in the cold weather in. 
 India. 
 
 Hhie of us reared adults from full-grown larva* kept on <lamp blotting pajier (in 
 India), but found that the y»>ung larva* die<l when kept under these conditions. 
 
69 
 
 perish in the unsuitable pools, or that the adults gemTally return to tlie same ]mk)1s 
 in order to lay their v^i;i*. It seems likely that the adults generally lay their eggs in 
 the pools in which they themselves were bred, and that the insects thus learn by 
 experience the places most suitable^ for them. 
 
 (7) Detection. — It is easy to overhjok AnojtJiehs iarvje unless they are >i«';irched for 
 in a bright light. 
 
 (8) Piipie. — The })uj>a' of Aii<q>}u'le>i seen) to be smaller than those of tlu'; coiii- 
 moner species of Cuh'x. They reijuiie about forty-eight hours to reach maturity in 
 vitro; perhaps less in natural conditions. 
 
 10. BIONOMICS OF ADI'LT ANOPHELES. 
 
 (1) Ilatcliing. — The adults generally hatch out in the evening; but their exit seems 
 often to depend on the meteorological conditions of tlie moment, an«l appears to be 
 delayevl by rainy and windy weather. 
 
 (2) Food. — They can easily be kept alive in glass cages, test tubes, Ijottles, etc. 
 We kept some in this manner for a fcjrtnight, and could doubtless have kept them 
 longer if we had wished to do so. We are able to confirm Bancroft's statement (18) 
 that gnats feed on bananas; but they seem to prefer the fresh fruit. During the day 
 the insects remained at rest on the walls of the cage, but in the evening l)egan to 
 fly about and to walk over the fruit, plunging their proboscis into it in many places, 
 so that the banana was sometimes covered with gnats, both male and female. They 
 also drink water frequently, and each can often be seen to be distended with the 
 fluid. Raw meat was offered to them, l)ut they could not be observed to touch 
 it. Earth i)laced at the bottom of the cage seems to be suitable for them. 
 
 According to the accounts of the soldiers at Wilberforce, they bite almost entirely 
 in the evening and night, but have been known to feed on men during the day. 
 They can certainly be fed on men artificially during the daytime, simply by placing 
 them in test tubes and then aj^plying the mouth of the tube to the skin. The stom- 
 ach can be observed to become distended in from one to two minutes or more; after 
 which the insect continues to suck, but commences to evacuate by the anus serum 
 containing a small jjercentage of red corpuscles. Cule.r voids only a clear fluid under 
 the same circumstances. The insects sometimes continue sucking like leeches for 
 five or ten minutes, voiding blood all the while; but at other times soon withdraw 
 the proboscis and then try another spot. It was noted, however, that Anopheles 
 fed in this manner, even after they had remained sucking for five or ten minutes, 
 never showed any great distension of the abdomen; while the contents of the stom- 
 ach still remained for some time transparent and red as seen through the scales of the 
 living insect. Moreover, in these cases the meal was generally digested or voided 
 within about twenty-four hours. 
 
 On the other hand, AnopJieles which had fed themselves under natural conditions 
 generally presented a very different appearance. They were enormously distended; 
 w hile the contents of the stomach were thick, opaque, and black, and sometimes did 
 not disappear for three days. The only inference is that, under natural conditions, 
 the insects w^hich can manage to do so gorge themselves over and over again during 
 the night — probably from the same subject. 
 
 (3) Propagation. — We also observed that while naturally fed gnats invariably laid 
 eggs after two or three days, those which had been bred from the larvae in captivity, 
 and had then been isolated and fed in test tubes, never did so, although before being 
 isolated they had long been in company with males. The inference is that fertiliza- 
 tion takes place only after the female has been fed. 
 
 We noted also that in a cage where many male and female gnats, Cidex and A no- 
 pheles, were kept together for weeks eggs were never laid, although the insects were 
 fed as described on bananas, and the cage contained water for them to lay their eggs 
 in. It seems, then, that a meal of l)lood is necessary before fertilization. 
 
70 
 
 r^Mtly, Nvc <)l>w*rviMl tliat previously U'*\ iiinl fertilized inneetH would lay a neeoutl 
 l)atth of rt^gs after a se<-()U<l nieail of I>1c»«m1 without a neeoud fertilization, Imt never 
 laid aK*«»»nd l»at«'h «>f i-jrj^ without a st-cuiid iiu-al <tf 1»1<kmI. That is, one fertiliza- 
 tion .viullic-eH for s«'\«'r:il 1 >;itel u*s of «'^';:.<, ImM one niral of Idood for oidy one hatch of 
 
 Tlu'se ol>sfrvations arr wlioliy in lui-ord with the resuUs «tf the ijrolonj^tMl study of 
 many kinds of gnats nia<h' in India hy oiu* of us; and it thfrefort* seiMns likrly tliat 
 tin* foll.iwin},' law is likely to hold l'oo.I f..r the Cnlir'nl:, which f»-cd on men, at l<-ast 
 for tlu* commoner species. 
 
 Althou^di these irnats can live indelinilely on iiiiii and iwrhaps jnices of j)lants, the 
 female re«|nires a meal of hlood, iMtth for fertilization an<l for the develo]>nient <»f her 
 o\a. In other \sords, tln' ins«'cls need hl<»od for the j»ri)pajration of their species. 
 
 \\\ 1 was ne\er I'onnd in male Cn/irti/.i in P'reelow ii, according' with the jreneral 
 
 law. 
 
 (4) J/aitiifs. — The lar;je majority of Aiiojthrlis <-aught hy us in dwellinjrs were 
 females whiih were generally much gorged, and, if fed at all, were invariahly fertil- 
 ized; in other words, the males an<l unfe<l, or only slightly fe<l, females do not gen- 
 erally remain in the houses during the daytime, or if they <lid remain, kejjt in the 
 roofs or other dark jdaces where they were little ohserved. On the whole, we think 
 that only tho.^e females which are so gorged that they can not Hy far remain in the 
 houses during the <lay. AVe oliserved that if a cage full of .l/*oy>A///.s wa^ disturl)ed 
 in tlu- daytime, the insects always struggle<l toward the light as if to fly out from 
 the windows, ami several which escaped fronj the e^iges actually did s<». On one 
 occasion a large numlK*r escape<l from their cage during the night in the rooms <tccu- 
 pied hy one of us; none of them could he stH'U next morning. 
 
 Yet we may 1m* (juite sure that lM>th the males and the uufe<l females haunt the 
 houses during the night. The invariahly fertilized conditions of the gorged females 
 caught in the houses show that the males must ln' present in tiie houses when the 
 females feed, sinci' the latter are often so much disten<ied after feeding that they are 
 oiniously unwilling to fly even a few feet from the 1h*<1 (»f their victim; in other 
 words, fertilization nuist take i)lace within the houses. The nnfe^l females must, of 
 course, resort to human ha])itations during the night in order to o])tain their food 
 at all. 
 
 These facts would seem to indicate that in Freetown in the rainy si^ason the 
 AiiDjtht'Jex resort to the houses during the night, hut that all except thegorge<l females 
 liv<^ elsewhere during the daytime — po.ssihly sleep in the trees and shruhs. The 
 j)oint is ot' interest as tending t<» show that large muu]>ers of Aiiophtlrs may he pre.^nt 
 in a dwelling during the night, without it heing easy to And them during the <lay. 
 
 It should, however, he added that in India males and unfed females were often 
 found in the houses in large numbers )»y one of us. Possibly different sj^eies have 
 different habits in this respect. 
 
 Several ol<l residents of the country inf(»rme(l us that gnats are usually \»'ry preva- 
 lent in the presence of nuich vegetation — i'sj>ecially long >;rass and undergrowth. 
 Though it is diflicult to see how such can favor the larxa', we can understand that 
 nuich vegetation can shelter the a<lults of certain sjx'cies, which may even ft»e<l on 
 particular kin<ls of plants when they can not obtain blo(»d, and may conse<juently 
 find it easier to live where these jilants afford them both food and shelter than else- 
 where. It must also be ri'inendn'red that gnats can certaiidy bite birds and other 
 mammalia lM'.<ides man; and that such are apt to congregate where there is nmch 
 vegetation. ( )n the whole, then, there is nothing improbable in the idea that the 
 Freetown Aiinjiluhs should live outsi<le the houses in the daytime. 
 
 o 
 
1 
 
UrjiVERSlTY OF FLORID/ 
 
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