﻿134 Journal New York Ent Soc. [Voi. in. 



ON THE CORRELATION OF HABIT IN NEMOSCER- 

 OUS AND BRACHYCEROUS DIPTERA BETWEEN 

 AQUATIC LARVvE AND BLOOD-SUCK- 

 ING ADULT FEMALES. 



By C. H. Tyler Townsend. 



It is a rather striking fact that in most of the dipterous families 

 whose adult females are of mammalian blood-sucking habit, the larvae 

 are commonly aquatic. Such larvte breathe in various ways, but often 

 by means of tracheal gills or vesicles. Especially is this correlation of 

 habit evident in the older families of diptera, the Nemocera and those 

 more nearly allied to them. It seems strange that such an apparent 

 connection in habits in these families should have escaped the notice of 

 previous observers, yet no one seems to have ever remarked upon it. 



The following families possess such blood-sucking females. The 

 known blood-sucking genera are starred, while all the other genera 

 given possess mouth-parts capable of biting, though they are not so far 

 known to suck blood. 



Simulid£e : Single genus Simtiliiim.'^ 



Culicidse : Megarrhina,'^' Cii /ex, ^- Anopheles,''^- Aides, 



Corethra, Mochlonyx (European). 

 Chironomidae : Cerafopogen^ (some spp. ), Terres- 

 Orthorhapha j fhes,"^- Oecacta,'^ Chironoinus, Ta?iypi/s, Diamesa, 

 Nemocera. \ CJiasmatoiiotits, Hydrolncnus, Heteromyia, Coryno- 



jieiira (Eu.). In fact all the known genera except 



Cliinio (Eu.) have biting mouth parts. 

 Psychodidas : Phlebotonms'^ (Eu.), and perhaps some 



other cenera. 



Tabanidas:* All known genera, about forty in 



number, are without exception blood-sucking in 



Orthorhapha ) i uv • ..u r i 

 -n _ _,_ ^ _ habit m the female. 



Leptidae: Syinphoromyia'^, Leptis, Atherix and 



other genera. 



Brachycera. 



( Muscidae : Stomoxys'^-, Hceinatobia'^, Glossina'^ 

 Cyclorhapha. j ^^j^^ ^^^^^g ^^ ^^ ^^^^j^^^^ 



I exclude the HiPPOBOscm.t and Nvcteribid/e, as being degradedly 

 parasitic in both sexes, and as not possessing a blood-sucking habit of 



