608 
DIPTERA. 
The economic importance of the family in India is slight. They are 
predaceous, and perhaps therefore to be encouraged 
The family reaches its maximum abundance in temperate regions, 
and two or three hundred species are already known from Europe and N. 
America. In India Psilopus seems distinctly the dominant genus and its 
members are in some districts extremely common on broad leaves. Van 
der Wulp includes seven Psilopus and two Dolichopus in his list. A 
species of Psilopus is figured on PL LXIII. 
Phorid^. 
Small flies, generally black or yellowish . Head small with bristles pointing 
backwards, antennae very short with long arista . Thorax much 
rounded and hunched. Wings sometimes large, sometimes small , 
with characteristic venation. Coxae and hind legs rather long , hind 
femora often flattened or enlarged. 
These small hump-backed flies are often seen running about on 
leaves or windows, and are very common all over India, though perhaps 
less abundant in the plains than in the hills. 
The venation is peculiar (PI. LIX) and the 
real systematic position of the family is in 
doubt. The eyes are wide apart in both 
sexes, but the abdomen of the female is gen¬ 
erally more or less pointed, while that of the 
male is more often swollen at the end. The 
larvae (PI. LXV, fig. lOu) are rather flattened, 
often with pointed processes, and sometimes 
a breathing-tube at the tail end; they 
are found in all sorts of decaying matter 
and are also occasionally parasitic on living 
insects or their larvae. One species, 
Phora(C Cleghorni, is said to have been 
found as a parasite on Trycolyga bombycis , a 
Tachinid fly, which is itself a parasite on the true silk-worm Bornbyx 
mori (I. M Notes). Several curious wingless Phorids have been 
recorded as living in ants’ nests in various parts of the world 
(fig. 402). The pupa has two thoracic breathing-processes or tubes 
which protrude from the old larval skin within which it lies 
enclosed (fig. 401). 
Fig. 400— Trineura aterrima 
(Simla) x 8. (After 
Brues.) 
