534 Observations on Habits and Parasites of Common Plies 
by braconids. It is hoped that during the coming season opportunities 
may be afforded of studying more fully the habits of this interesting 
parasite. 
Of the other species of chalcid, a Pteromaline which was larger than 
M. acasta, only a few specimens were found in the puparia examined in 
November, 1915. Eight males and twenty-four females appeared, 
however, between April 15-22 from eleven out of 368 intact 1914-15 
winter pupae, kept to observe further developments in room B. 
Chalcids are very prolific, easily reared, present no difficulties in 
artificial distribution, and might be utilised with great advantage in 
destroying fly pupae. 
Table V summarises the results of the observations on 1914-15 
winter pupae. 
Froggatt’s (1915) recently published observations on the habits of 
a chalcid parasite, Nasonia brevicornis 1 , infesting the pupae of several 
species of blow-fly in Australia, are of great interest. He found that 
this parasite would attempt to deposit its eggs in larvae, but that the 
process took a considerable time and the creature was prevented from 
accomplishing its object by the movements of the larvae. 
“Some fresh pupae were then placed in the tube and were quickly 
settled upon by the parasites, which immediately began to lay their 
eggs within the pupae by inserting their ovipositors through the pupal 
covering. Their sense of location is evidently very acute, as pupae 
exposed anywhere in the Laboratory were always found and attacked 
by parasites, which had accidentally escaped from their tubes. 
“ The method of ovipositing is very interesting. The female wasp 
spends some time crawling over and over the pupae, constantly twitching 
and touching them with the antennae as if searching for the least 
resistant spot to puncture. When this is finally decided upon, she 
curves the tip of the body underneath the body and inserts the point 
of the ovipositor. The apex of the abdomen then springs back to 
almost its normal position, and in so doing exposes the full length of 
the ovipositor, which up to this time has been hidden in a groove along 
the ventral plates of the abdomen. 
“ The body now remains motionless, except for a slight twitching of 
the extremity and an occasional waving of the antennae The ovipositor 
is gradually inserted by what appears to be upward and downward play 
of the styles enclosed within the sheath. 
1 In 1911 the writer bred this parasite from the pupae of C. erythrocephala at 
Cambridge. 
