V Circular No. 40, Second Series. United States Department of Agriculture, DIVISION OF ENTOMOLOGY. HOW TO DISTINGUISH THE DIFFERENT MOSQUITOES OF NORTH AMERICA. In Circular No. 13, of this series, the writer discussed briefly the habits of one of our commonest mosquitoes {CuJex jmngeriH) and some what at length the I'emedies to be used against all mosquitoes. This account was abbreviated from the more detailed treatment of the sub- ject in Bulletin No. 4, new series, of this Division. Since the publication of this circular and of this bulletin wide- spread interest has been attracted to the subject of mosquitoes and their habits and also to the specific and generic distinctions which exist between different forms. This interest has arisen from the dis- covery that certain mosquitoes are intermediary hosts in the develop- ment of the micro-organisms of malaria. The connection between mosquitoes and malaria, although originally suggested in recent times by an American physician, A. F. A. King, was first demonstrated by experimental w^ork carried on by the English surgeon, Ross, the Ital- ians, Bignami, Grassi, and Bastianelli, and the German, Koch, while the American, McCallum, has followed out the life history of a mala- rial parasite of the common crow. The latest work of the foreign investigators shows that not only in South Europe but also in India and in West Africa only mosquitoes of the genus Anopheles are concerned in the transmission of the human malarial parasite, although mosquitoes of the genus Culex are connected with the transmission of the malarial diseases of birds and possibly of other animals. These conclusions have been confirmed by the Americans, W. S. Thayer, F. N. Berkeley, and Albert Woldert, for America, so far as their work has gone. The latest announced results of the most advanced investigators seem to show that mosqui- toes form the principal if not the sole means of transmission of mala- ria, and workers in all parts of the world, including many parts of the United States, are investigating the subject, more especially in rela- tion to local conditions. In the course of this work there has arisen considerable difficulty in ^(^ the identification of local species of mosquitoes. The literature of this group of insects is fragmentary and scattered. The list published in Bulletin No. 4, new series, of this office, above referred to (1896), is the most com- plete one which has been published for this country, and it includes a citation of very many actual localities of cap- ture of the different species which give us the first insight into the geographic dis t r i b u- tion of the different forms. Ver}^ many in- vestigators, mostly ph3^sicians, are calling upon this office for assistance in the de- termination of m o s - Fig. l.—A7iopheles piinctipeniiis, female, with male antennae at right qUltOCS, Or at leaSt and wing tip showing venation at left— enlarged (original) . for SOUIC indication of the characters by which the different forms mav be recognized. In answer to this "^^^ demand the follow- ing tables have been drawn up at the writer's request bv Mr. D. W. Coquii- lett. The}^ include all of the mosquitoes Avhich have been re- corded from North America, and com- prise, (I) a s^^nopsis of the five genera into which the lonp-- o beaked, })lood-suck- ing mos(iuitoes known to occur in North America are divided; (II) a syn- optic c()nsid(M'a- ,. f fh » . ' yui.2.—Ciik.v IrcniorhrincliHS, fonialo, showing the short \M\\\n wliich tlOn Ol tn(^ species distinfrnish Culex from Anoplioles; toothed front tarsal claw at of the glMUlS Alio- right— enlarged (original). pheles,- divided into (a) the recognized forms, specimens of which / / 3 occur in the Niitional Museuin collection, jiiid {h) the nnrccoonizcd forms, which arc known only from the literjitiirc; (III) a synoptic con- sideration of the species of the o-emis Culex, divided into ((t) a tal)Ic of the recognized species, and {h) an account of the unrecognized s})ecies; (IV) a brief description of the only valid known species of the geruis Psorophora; (V) a synoptic table of the three known species of the genus Megarhinus; and (VI) a synoptic consideration of the two known species of the genus Aedes. So far in the medical literature only the genera Anopheles and Culex have received consideration, Imt since this circular is intended simply to aid in the identitication of the ditlerent forms, the other three genera have been added in order to a\ oid confusion. Fig. 3.— Resting positions of Culex (at left) and Anopheles (at right), enlarged (redrawn from a rough sketch published in the British Medical Journal) . The figures which are given illustrate the structural points brought out in the synoptic tables and have been drawn by Miss Sullivan, of this office, under Mr. Coquillett's supervision. The figure repre- senting the difference in the resting positions of Anopheles and Culex has been redrawn from a sketch made by a member of Ross's expedi- tion to Sierra Leone. Neither the writer nor Mr. Coquillett is able to verify the suggestion that either of these insects uniformly rests in the positions indicated, although it is quite likely that the attitudes shown are the usual ones. RespectfuUv submitted. L. O. Approved: James Wilson, Secretary of Agriculture. Washington, D. C, February W, 1900. Howard, Entoriiologid. ^^\^20^ «;T^•Y^ plaKT SYNOPTIC TABLES OF THE NORTH AMERICAN MOSQUITOES. By D. W. COQUILLETT. I. — Generic Synopsis. The following table contains all the genera of the long-beaked mos- quitoes known to occur in North America. The males are readih^ recognized b}^ the antenna being densel}^ covered with long hairs; in the females the hairs of the antennae are short and very sparse. 1. Palpi in the male at least nearly as long as the proljoscis, 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 prol)oscis Aecles. 2. Proboscis straight or nearly so, colors of l)ody ])rown 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. II. — Genus Anopheles. (d) RECOGNIZED SPECIES. 1. 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. . pnnctipennis Say. Without such a spot 2. 2. Scales of last vein wholly black, palpi wholly black quudrimacuhUas Say. Scales of last vein white, marked with three black spots, palpi marked with white at bases of last four joints crucians Wied. (h) UNRECOGNIZED SPECIES. The following species which have been credited to our countrv have not been recognized Avith certainty; some of them probably do not belong to the present genus, while a few were evidently founded on badly rubbed specimens in which the distinctive characters were therefore wanting: anxaiVnnanus v. d. Wulp. I strongly suspect that this does not belong to the pres- ent genus; the description applies fairly well to the male of Culex cousobrinus Desv. ferrugiriosus Wied. This author proposes this name for the species previously descril)ed by Say under the name of Culex quuKpU'/mckitus, but the description which he gives differs so decidedly from the one published by Say as to give the impres- sion that it is founded on a different species. I strongly suspect that the type of ferrugmosus is a rubbed example of Anopheles crucians, which was descri])ed from the same locality. Say's description of his Culex quinquefasciqtus agrees very well with the species which I have identified as Culex impiger AValker. maculipennis Meigen. I strongly suspect that tliis European form is identical with our AiKqtheh'x quadriiuarulafus Say, but this i)()int can not be settled definitely at l)resent, owing to the lack of any European specimens for comparison with ours. iilgri]}es Staeger. This Euroiu'an si)ecies should be readily recognized by its uiisj)otted wings. iilh'niKtiiiis Wied. Differs from our other species by the snow-white apices of the tarsi. Auojiht'les jiirliiH Loew I think should be placed as a synonym of .1. rruciaux Wied. 5 Our rcH'oo-nizod s])oci('s of A!i()i)h('l(\s and their synonyms may therefore l)e listed as follows, the synonyms indented: crucians Wied, p ictus Loew. ? ferrugitiosKs Wied. punrtipemii.s Say. hiemalis Fitch. giiadrimaculatus Say. ? macidipennis Meigeii. HI. — Genus Culp:x. {a) RECOGNIZED SPECIES. Males. 1. Front tarsal claws l)earing a distinct tooth near the middle of the nnderside 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 middle , 2. Front tarsal claws with one tooth on underside of one of the claws, none on the other, bases of tarsal joints white, prol^oscis destitute of a whitish band near the middle fasciatus Fabr. 2. Tarsi distinctly white at leases of the joints ejcitans AValk. Tarsi not white at bases of the joints cousohriuus Desv. 3. Proboscis destitute of a whitish ring near the middle 4, Proboscis with such a ring, ends of tarsal joints white tarmlis Coq. 4. Bases of tarsal joints not white 5. Bases of tarsal joints white stimvhois Walk. 5. Petiole of submarginal cell less than one-third of the length of that cell. pungevs Wied. Petiole of sul)marginal cell at least one-half of the length of that cell. Impigcr Walk. Fetnales. 1. Front tarsal claws bearing a distinct tooth near middle of underside of each. . . 2. Front tarsal claws destitute of teeth 7. 2. Proboscis destitute of a white ring near the middle 3. Proboscis marked with such a ring, bases of tarsal joints white. tcTit iorhipx-Jt IIS Wied. 3. Bases of tarsal joints distinctly white 4. Bases of tarsal joints never white 5. 4. ^Nlesonotum marked with four stripes of silvery scales fasciatus Fabr. Mesonotum destitute of such stripes stimulans Walk. 5. Last two joints of hind tarsi never white 6. Last two joints of hind tarsi snow white ])osticatus Wied. 6. Abdomen marked with a cross band of whitish scales at base of each segment. impiger Walk. Abdomen never marked in this manner, but with a cluster of whitish scales at front angles of some of the segments triseriata Say. 7. Proboscis marked with a distinct whitish ring near the middle, tarsi white at sutures of the joints 8. Proboscis destitute of a whitish ring near the middle 9. 8. Tarsal joints white at bases only perturbans Walk. Tarsal joints white at both ends tarsalU Coq. 9. Tarsi white at bases of joints 10. Tarsi never white at bases of the joints 12. 10. ^Mesonotum never marked with stripes of silvery scales 11. Mesonotum marked with four stripes of silvery scales, first tarsal joint never marked with a whitish ring near the middle signifcr Coq. 11. First tarsal joint marked with a whitish ring near middle of each . excrncians Walk. First tarsal joint destitute of such a ring excitnns Walk. 12. Petiole of submarginal cell less than one-third of the length of that cell. pungent Wied. Petiole of submarginal cell at least almost one-half of the length of that cell. consobrinus Desv. (h) UNRECOGNIZED SPECIES. ammlatus Schrank, This European species was credited to our fauna by Osten Sacken. The description agrees fairly well with specimens which I have identified as e.vcitaris, Walker, except that in the latter there is no white ring on the femora toward their apices. boscii Desv. Probably a rubbed specimen of pungens. nigripes Zett. Black, the legs of the male dark yellow, hairs of pleura of female gray, a band of white scales at base of each segment of her abdomen. rubidus Desv. The description was apparently founded on a rubbed specimen of Psowphora ciliata. testaceiis v. d. Wulp. Is probably a somewhat injured example of consobrinus. incidens Thomson. Is evidently a synonym of impiger Walker. bigoti Bellardi. According to the figure and description, the bands of black scales are at the bases of the abdominal segments; in the recognized species these bands are always at the apices of the segments. In other respects this species must greatly resemble pungens. cubensis Bigot. Apparently founded on a badly rubbed specimen of pungens. frater Desv. This name was proposed for the Culex fasciatus of Wiedemann under the impression that this is not the same species as the one described by Fabricius under the same name. It seems quite certain, however, that the word " proboscis " in Fabricius' description was simply a lapsus for "palpi," and with this emendation the two descriptions agree very well. mexicana Bellardi. Is evidently a synonym of posticatus. provocans Walker. Is probably a synonym of slimulans: In some specimens of this species the light color at the bases of the tarsal joints is very indistinct. territans Walker. Is apparently a synonym of pungens. Our recog-nized species of Culex and their synonyms may be listed as follows, the synon3^ms indented: consobrinus Desv. ? annuUmanus v. d. Wulj) (Anopheles) . impatiens Walker. inornatus Williston. pinguis Walker. punctor Kirl)y. ? testaceus v. d. Wulp. excitans Walker. ? (I niiiUdliis OAtm Sacken (ncc Meigen, etc.). excruciaiiK Wal kcr. fasdatus Fal)r. frater DeHv. mosquito Dghv. taeniafu!^ Wied. imjngcr Walker. implaca h ills Wal ker. incident Thomson. ? (juinquefasciafus Say. perturbanH Walker. posticatus Wied. ? mexiccmus Bellardi. musicus Say. pungens ^y led. ? 6osm Desv. ? cubensis Bigot. ? territans Walker. signifer Coquillett. stimulans Walker. ? provocans Walker. taeniorhynchus Wied. damnosus Say. sollicitans Walker. tarsalis Coquillett. iriseriatus Say. IV. — Genus Psorophora. Our single species is of a yellowish color, usually varied with brown, the bases of the tarsal joints white. It is considerably larger than any of our other species of yellowish or brown mosquitoes: ciliatus Fabr. conterrens Walker. molestus Wied. ? rubidus Desv. V. — Genus Megarhinus. Our three species are among the largest in this family, and are not known to occur north of the District of Columbia. The}^ may be separated as follows: All tarsi marked with white rutila Coq. Hind tarsi alone marked with white portoricensis Koeder. None of the tarsi marked with white Juanorrhoidalis Fabr. VI. — Genus Aedes. Our two species are among the smallest of our mosquitoes, and have a pale brownish ground color. The}^ ma}^ be distinguished as follows: Thorax marked with a median violet blue stripe sapphinniis O. S. Thorax destitute of such a stripe fuscus O. S. o A UNIVERSITY OF FLORIDA Wllllllillllllllllillllllllll 3 1262 09228 3315