374 JOURNAL, BOMBAY NATURAL HIST, SOCIETY, Vol. AX VIII. 
dipterous larva, whether free or a parasite, always finds itself among 
rich supplies of food. For this it must thank its mother who has 
had a wonderful instinct and in some cases the needful specially 
adapted ovipositor. This explams why in the Diptera, particular- 
ly those in which the larva is parasitic, we find perfect instinct and 
perfect structure in the imago coupled with comparative degradation 
in the larva. Hence also arises the vast transformation which takes 
place at the pupal stage. 
a 
I propose now to give some account of the structure and life- 
history of the species which compose the families with parasitic larvae. 
It will be possible to take a survey of the varieties of hosts that are 
attacked, of the adaptations which these Dipterous families have 
evolved in connection with their parasitic habits, and of the 
most common representations of each family im India. The 
Pupipara will best be treated asa group by themselves; though 
some entomologists regard the group as polyphyletic and none are 
agreed what value should be accorded to it. The families which 
compose the Pupipara have little in common except habits. Two 
of the families are parasites of bats and therefore unfamiliar to most 
people but to the lover of parasites much the most interesting 
of all Diptera. In the preceding table I have enclosed Braulidae 
in brackets because the pupiparous habits of the single species 
are doubtful. It is a minute insect found clinging to bees and not 
recorded from India. 
Bombylud@. These conspicuous flies are members of a large 
cosmopolitan family and may be recognised by their habit of remaining 
poised for some minutes in the air and then darting away. All are 
lovers of sunshine and many are frequenters of arid, sandy places. 
They are familiar features in the Indian plains.* Many attain con- 
siderable size and some are gorgeously coloured and coated with fur. 
The wings are often prettily marked. This family contains many 
of the most briliantly coloured Diptera. The abdomen in the sub-. 
family Bombylune is almost globular and clothed with a dense furry 
pubescence like a bumble-bee. The adult flies frequent flowers and 
feed on honey and pollen. The larve feed parasitically on the larvee 
of other insects, in some cases Lepidoptera and Hymenoptera, in 
others on Diptera (Tachinids) which are themselves parasitic on 
lepidopterous larve. The female fly is not provided with any 
specially adapted ovipositor for placing the eggs which are dropped 
from above haphazard in the vicinity of the larval host. The Bomby- 
lnd larva is amphineustic and cylindrical, with thirteen segments. 
* A description of the Indian genera and species will be found in the recent (1920) 
volume of “The Fauna of British India” Diptera Brachycera,by E. eae Vol. 
Tpp. 173-295. 
