632 
DIPTKRA. 
The flies are as a rule easily recognised from the above description, 
the only ones with which they are liable to be confounded being the 
Fig. 417— Wing of Tkypetid showing the 
indistinct Sub-costa. 
(After Loew .. xl6.) 
Ortalidce . In these latter, however, there are no fronto-orbital bristles 
(i.e., the front is not bristly all the way down the sides), the sub-costa 
runs into the costa at an acute angle, not a right angle, and is not indis¬ 
tinct at the junction, while the anal cell, though large, is often very in¬ 
distinct. The family is of importance because it contains the bulk of the 
“ Fruit-flies,” whose larvae by their presence often render uneatable the 
mangoes, peaches, oranges, melons, gourds and the fruits of various 
other cucurbitaceous plants in which they are most usually found. In 
other countries Ceratitis capitata is a very serious pest of oranges and 
other fruit, but does not occur in India, though an allied species has been 
found in the North-West and in Bombay. In this genus (Cerat es) the 
males have on the head two long bristles with broad leaf-like tips. The 
ordinary Indian Fruit-flies belong to the genus Dacus, and there are some 
half-a-dozen species which have attracted notice owing to damage inflicted 
on fruits in various districts, the troublesome species of fly varying 
with the locality and to some extent with the time of year. All the 
commoner species of Dacus have a strong family likeness, being yellow 
or reddish yellow with more or less of dark greyish black, the dorsal part 
of the thorax being frequently blackish, often with yellow marking. 
The general type of colouring can be seen on PL LXYI which represents 
Dacus diversus, Coq. The life-history of Fruit-flies, speaking generally, 
is as follows :—the long white eggs are laid just under the skin of the 
fruit by means of the long horny ovipositor possessed by the female ; 
they hatch in two or three days and the young maggots tunnel into 
the fruit and continue eating for a fortnight or so ; they then as a 
