166 HYMENOPTERA. 
group. In no branch of entomology is study so much required and no 
branch is likely to give results of greater economic value. Parasitic 
Hymenoptera are the greatest checks on insect increase and their work 
is of the utmost importance ; this has been recognised elsewhere and the 
study of Parasitic Hymenoptera should advance when more encourage¬ 
ment is given to Entomology generally. As it is we are unable to do 
anything to assist these insects save in very special cases ; when it was 
learnt that the parasites of the Indian bollworm had been destroyed by 
cold, and these were reintroduced from places not affected by the cold, 
the first step to the utilisation of parasitic insects was taken in India; 
but this was a special case and until we know our parasites, we cannot 
expect to be able to make progress in this branch of entomology. 
Cynipid^e. — Gall-wasps. 
Small to minute insects , the forewing with no stigma and not more than 
-five closed cells , the hindwing with two or three nervures; the antennae 
are straight with less than 16 joints. The pronotum reaches the 
insertion of the forewings. 
Whilst the habits of the family are of great interest, almost none 
are described from our region and the habits of these are unknown. One 
species ( Onychia striolata, Cam.) from Bengal will, if it shares the habits 
of the rest of the genus, be a parasite on a Dipterous insect. Others are 
known to inhabit galls. Cameron has described Callirhytis semicarpi- 
folice as being reared from an acorn ( Quercus semicarpifolid) collected 
in the North-West Himalayas. (Entomologist, 1902, 38.) 
In general, the Cynipidce are either (1) inhabitants of galls or other 
portions of plant tissues, (2) guests of the above gall-inhabiting species 
or (3) parasites on other insects. Taking first the gall-insect, it may be 
remembered that many other insects make galls and that not every gall 
is due to the work of the Cynipid; also that a gall may contain the Cyni- 
pid that caused it or either guests or parasites. A number of very simi¬ 
lar insects may therefore be reared from the same galls and it is no easy 
matter to sort them out. It is very much to be desired that the study of 
galls may be taken up in India, and with it, the study of the relations 
of the insects inhabiting such galls. Galls abound even in the plains and 
those on the mango tree alone will give ample scope for investigation. 
Having cleared them up, the study of galls on other trees in the plains 
