﻿Sept. 1895.] 



TowNSEND. Habits of Diptera. 



135 



comparatively recent acquirement in the female sex. They suck not 

 only mammalian blood (horses, sheep and bats), but also that of birds. 

 The larval habits of the genera above named, so far as known, are 

 as follows: 



Simulium : Larvte live in water, 



usually swift running water. 

 Megarrhina : In water. 

 Culex: In water. 

 Anopheles : In water. 

 Aedes : Unknown. 

 Corethra : In water. 

 Mochlonyx : In water. 

 Ceratopogon : Some species live 



in water, others in foul vegetable 



matter. 

 Terresthes : Unknown. 

 Oecacta : Unknown. 

 Chironomus : Some species in 



water, others in earth and dung. 

 Tanypus : In water. 

 Diamesa : Unknown. 

 Chasmatonotus : Unknown. 

 Hydrobsenus: In slimy mud. 



Heteromyia : Unknown. 



Corynoneura : Unknown. 



Phlebotomus: Probably aquatic, 

 as some Psychodid larvae live in 

 water. 



Tabanidse : The larvae of Ta- 

 banus live in water or in moist 

 earth, and those of Chrysops 

 probably in slimy mud and 

 water. The larval habits of 

 other genera are not known, but 

 are doubtless the same. 



Symphoromyia: Unknown. 



Leptis : Moist earth. 



Atherix : In water. 



Stomoxys : In horse dung. 



Hgematobia : In cow dung. 



Glossina: Unknown. 



The mode of larval respiration in the strictly acquatic forms, so far 

 as known, is as follows: Siinuliiim larvae breathe by means of a tracheal 

 network in the skin, also by tracheal vesicles at the anal extremity. 



Chironomus, Tanypits, and the aquatic larvi-e of Ceratopogon have 

 a closed tracheal system, rudimentary and completely closed mChirono- 

 mus. In Corethra it is also rudimentary, and perhaps supplemented by 

 respiration through the skin. 



Culex, Anopheles and Mochlonyx have a pair of longitudinal 

 tracheee, ending in anal spiracles, through which they inhale air. They 

 also, together with most Chironomidje are provided with various 

 branchial appendages. 



Some Psychodid larvae possess branchi^ of various shapes. Further 

 notes of interest in this connection are the following : The European 

 genus Clunio Haliday is the only known Chironomid genus in which the 

 proboscis is rudimentary and almost entirely wanting. 



