BULLETIN OF THE CALIFORNIA INSECT SURVEY VOLUME 1, NO. 2 THE MOSQUITOES OF CALIFORNIA BY S. B. FREEBORN and R. M. BOHART (Division of Entomology and Parasitology, University of California 1 UNIVERSITY OF CALIFORNIA PRESS BERKELEY AND LOS ANGELES 1951 BULLETIN OF THE CALIFORNIA INSECT SURVEY Editors: E. 0. Essig, S. B. Freeborn, E. G. Linsley, R. L. Usinger Volume 1, No. 2, pp. 25-78, plates 2-8 Submitted by Editors, November 28, 1950 Issued June 8, 1951 Price 50 cents UNIVERSITY OF CALIFORNIA PRESS BERKELEY AND LOS ANGELES CALIFORNIA CAMBRIDGE UNIVERSITY PRESS LONDON, ENGLAND PRINTED BY OFFS67 IN THE UNITBD STAThS OF AMERICA THE MOSQUITOES OF CALIFORNIA Ihe first general publication on the mos- calts might be aptcalts, terrttans or boharti. In quitoes of California was by Quayle (1906). In the the case of the Culex piptens -quinque,+asciatus same year Dyar and Knab, dismayed by the confused complex, our distribution records are based pri- jumbling of genera and species in lheobald’ s writ- marily on material of which we have examined male ings, proposed an independent classification based genitalia. Furthermore, the county records of com- on larval characters and the thesis that well-de- mon species, such as C. tarsalis and C. incidens, fined differences apparent in the larvae should note only token occurrences and arc repeated with- be reflected in the adults. lhey illustrated their in a countyonly when there are sigificant ecolog- hypothesis by the German proverb that “Wer A sagt ical variations in the county, such as elevation muss auch B sagen. ” lheir contribution brought or a distinction between coastal and inland dis- order out of confusion and their later monograph tribution. It is hoped that collectors will aid written with Howard laid the foundation for the in filling in the existing gaps by submitting systematic study of mosquitoes in the United specimens to either the California Insect Survey - States. University of California, Davis or brkeley-or to the hreau of Vector Control, State Department of In 1926 Freeborn published re-descriptions, Public Health, Milvia Street, Berkeley. keys, and ecolokical notes on the 30 species of mosquitoes then known to occur in the state. In No group of insects of canparable size in the 1941 Reeves presented a paper on California rnos- world has received so much attention as the mos- quitoes, and a key which included one additional quitoes and no area of the world of comparable species was mimeographed and distributed. As a war- size has had its mosquitoes studied so thoroughly time contribution, Freeborn and Brookman (1943) as California. Ihe latter statement is true only published an identification guide to Pacific Coast because of the pioneering work of Quayle, Herms, mosquitoes. and Gray and scores of workers who followed them. In addition, the Mosquito Abatement Districts, Since the last complete treatment of the spe- whose accomplishments and programs are now checked cies of California, several new ones have been by entomological findings, have added significantly described, and reBxamination of existing collec- to our fund of information. By the same token, the tions has disclosed species not previously report- coiiperative research program of the Hooper Founda- ed. Gnversely in one instance - that of Aedes tion for Medical Research of the University of irnpiger - a check of the specimens on which the California and the U.S. Public Health Service on only existing state records were based has re- the transmission of the encephalitides has accumn- vealed them to belong to species other than in- lated substantial amounts of taxonomic and ecologi- piger. In addition, it is now possible to segre- cal infomation. Also the Bureau of Vector Control gate accurately the component species of some of of the State Eepartment of Public Health and its the hitherto baffling complexes, such as that of assigned personnel from the U. S. Public Health Culex apicalis, territans and boharti. Service has been an unusually potent force in the study of all phases of mosquito life. Despite the ?he records of these changes are, in sane in- fact that this bulletin contains considerable stances, already published in various entomological original taxonomic material and represents a vast journals, but to date they have not been collected expenditure of time in the collection of field for ready reference nor incorporated into existing material and the checking of collection records, keys. New records and synonymy since Freeborn (1926) the authors present it chiefly as a compilation are cited in the present paper, but older synonymy of the work of others in the agencies mentioned which is recorded in that work is not repeated here. above, all of whom have cooperated with the en- thusiasm that should be typical of all fields of We realize full well that our records of dis- biological research. tribution are incomplete. Unless otherwise sta- ted, we have included only records for which we Although we have been aided in a very sub- have been able to see the actual specimens person- stantial manner by scores of individuals, special ally. Existing published records of well-qualified acknowledgment should be made to Alan Stone and investigators are not always trustworthy, largely Willis Wirth of the U.S. National Museum, R.L. because of nanenclatorial changes caused by a more Usinger and W.C Reeves of thebiversity of Cali- complete understanding of the mosquito fauna. For fornia, Bernard Brookman of the U.S. Public Health instance, records of Anopheles nacul ipennis might Service, and Ernestine ‘Ihurman of the California be either occidentalis or freeborni and Culex api- State Bureau of Vector Control. 25 Keys to California Mosquitoes Genera of Mosquitoes Based on Adults 3. Distal half of siphon adapted for pierung underwater plant tissue (fig. 11) ..... 1. Scutellum rounded posteriorly and with mar- ...............Mansonia (p.51) ginal hairs arranged in an unbroken line; Siphon not adapted for piercing plant tissue abdomen without scales; females with palpi (fig. 10) ...... .Orthopdoa?yia (p.50) about as long as proboscis. Anopheles(p.26) Scutellum trilobed posteriorly and with bris- 4. Upper head hair With slender branches, lower tles in three groups; abdomen with evident head hair single and coarse ........ scales; females with short palpi. .... .2 .............Uranotamia (p.50) Upper and lower head hairs not as above . , 5 2. Second marginal cell (bounded by branches of first fork vein) less than half as long as 5. Siphon with a pair of large basoventral hair its petiole. .......Uraotoenia (p.50) tufts (fig. 9). ......Culiseta (p.31) Second marginal cell at least as long as its Siphon without a pair of large basoventral petiole. .................3 hair tufts. ............... 6 3. Fourth fore tarsal segnent about as long as 6. Siphon with three or nmre pairs of ventrally wide; mesonotum marked with longitudinal located hair tufts (inserted below the white lines. ......Orthopodomyia (p. 50) lateral line) .........&lex (p.32) Fourth fore tarsal sewent much longer than Siphon with one or rarely two pairs of wide.. ................. 4 ventrally located hair tufts. ...... 7 4. First segnent of hind tarsus with a median 7. lufts of ventral brush not inserted jn pale ring; wing scales mixed dark and saddle. ............Aedes (p. 29) white. .................. 5 Tufts of ventral brush inserted in saddle First sepent of hind tarsus without a median which completely rings anal segnent .... pale ring. ................6 ..............Psorophora (p.50) 5. Spiracular and postspiracular bristles present; abdaninal tergites with many pale apical Adult Females of Anopheles scales, frequently forming a triangle. ... .............. Psorophora (p.9) 1. Wing scales unicolorous but clumped to pro- Spiracular and postspiracular bristles absent; duce dark spots ............. 2 abdominal tergites with laterobasal pale Wing with patches of pale scales. ..... 3 spots ............Afansonia (p.51) 2. hinge scales of wing uniformly dark. .... 6. Postspiracular bristles present; spiracular ..............f reeborni ( P. 34.1 bristles absent; female abdomen pointed at Fringe scales at wing tip whitish to bronzy tip ...............Aedes (p.n) ............ .occi&ntalis (p.36) Postspiracular bristles absent; female ab- domen blunt at tip ........... .7 3. Palpusbanded.. .............. ...pseudopunctipennis franciscanus (p.36) 7. Spiracular bristles present, yellowish; mostly Palpus entirely dark scaled ......... large mosquitoes. ..... Culiseta (p. 30) .............punc tipennis (p. 38) Spiracular bristles absent; medium to small mosquitoes. ..........Culex (p. 31) Males of Anopheles Based on Genitalia2 Genera of Mosquitoes Based on Fourth Stage Larvae 1. Claspette with inconspicuous bristles on 1. Eighth abdominal segment without a respira- subapical lobe and 2 long slender ones on tory siphon ........Anopheles (p. 27) apical lobe, ninth tergite without well- Eighth abdaninal segment with a respiratory developed lobes .............. siphon. ................. .2 ...pseudopunctipennis franciscanus (p.36) Claspette mth two stout setae on subapical 2. Siphon without .a pecten .......... 3 lobe end one on apical lobe which is usually associated with a snaller internal seta and Siphon with a pecten. - - - . I e . 4 'The characters used in this key and .the one fol- 'Males are more satisfactorily separated by the lowing are not all neric in the broad sense and will wing pattern (see above). not necessarily holyfor species outside of California. 26 THE MOSQUITOES OF CALIFORNIA 27 a very small one between; ninth tergite with 4. Basal pale band of third hind tarsal segment finger-like lohs . I . punctipemis3 (p.38) covering less than one fifth of segment as freeborni (p.34) seen from front; basal pale bands of fourth ’ occidentalis (p.36) and fifth abdominal tergites indented toward middle or divided into two spots ...... ................vexans (p.49) Fourth Larval Stage of Anopheles Basal pale band of third hind tarsal segment covering one third or more of segment as 1. Inner clypeal hairs widely spaced, outer cly- seen from front; basal pale bands of tergites peals bare, inner antennal surface with small not conspicuously indented toward middle .