﻿376 F. W. EDWARDS — REVISED KEYS TO THE 



Genus Ochlerotatus, Arrib. 

 (including Stegomyia, Theo.) 



1. Antennae short, without hair-tuft on shaft ; anal brush small and 



not very distinct ... ... ... ... ... ... ... 2. 



Antennae longer, with hair-tuft ; anal brush quite distinct ... 3. 



2. Siphon more than twice as long as broad, the hair-tuft well 



beyond the middle ; comb scales 8-9, barbed ... S. fasciata (F.). 



Siphon less than twice as long as broad, the hair-tuft at about the 

 middle; comb scales 10-12, simple ... S. africana, Theo., and 



S. ajricoargentca, Theo. 



3. Median hairs on head, single... ... ... ... ... ... 4. 



Median hairs on head, triple or multiple ... ... ... ... 5. 



4. Pecten without detached teeth outwardly ; siphon less than three 



times as long as broad ... ... ... ... S. sue/ens (Wied). 



Pecten with detached teeth outwardly ; siphon more than three 

 times as long as broad ... ... ... >..(). nigeriensis (Theo). 



5. Median tufts on head each composed of three hairs ; pecten with 



6-8 teeth wide apart ... ... ... ... ... ... 6. 



Median tufts on head each composed of 6 to 8 hairs ; pecten with 

 12-18 teeth 7. 



6. Siphon curved, four times as long as broad ; comb with about 



6 teeth ; papillae four or five times as long as anal segment 



0. punctothoracis (Theo.). 

 Siphon straight, three times as long as broad; comb with 8 teeth; 

 papillae three times as long as anal segment O. caliginosus (Grab.). 



7. Comb consisting of five large teeth ... ... 0. domesticus (Theo.). 



Comb consisting of a patch of small scales (20-30?) ... ... 8. 



8. Hair-tuft normal, branched, situated in middle of siphon 



O. marslialli (Theo.). 

 Hair-tuft reduced to a single hair, situated at | of siphon 



O. nigricephalus (Theo.). 



The larva of O. longipalpis Griinb. (pollinctor, Grah.) has been insufficiently 

 described, and the specimens in the British Museum are too damaged for purposes 

 of tabulation. 



The comb in the last two species is very difficult to see, and I cannot determine 

 the number of scales. 



The larva of S. fasciata when young has only the apical half of the siphon 

 darkened, and this should greatly help in its determination, as I know of no other 

 similar case. 



The genera Stegomyia and Ochlerotatus do not seem separable from one another 

 or from the genus Aedes when larvae alone are considered. All the known 

 Stegomyia larvae, except that of S. sugens, agree in having a tuftless antenna ; 

 these species in the adult have the larger claws of the male simple, at least on the 

 mid legs. S. sugens, however, which has toothed male claws, has typical Stegomyia 



