526 Observations on Habits and Parasites of Common Flies 
the experiment was made that both sets of parasites emerged from eggs 
deposited in the autumn of 1914, for there was little chance of wild 
braconids gaining entrance to the box in which the pupae were kept, 
and those which emerged were collected and killed each day. 
A point of some interest is that the first batch of braconids began to 
emerge just at the time when blow-flies reared from pupae, which had 
wintered in the earth, commenced to lay eggs, and the parasites therefore 
appeared when larvae were becoming numerous. The second batch 
Fig. 12 Alysia manducator ( x 6) from pupa of G. erythrocephala. The lower left-hand 
figure represents a specimen (nat. size) which emerged in the spring, and the right- 
hand figure one (nat. size) which emerged in the autumn. 
appeared about the time that the autumn larvae, which spend the 
winter as pupae, are found (see p. 461). 
The same species of braconid were also obtained in May, 1915, from 
blow-fly pupae dug up from earth in which they had pupated under 
natural conditions in the autumn of 1914. The pupae were taken 
from the earth on April 24, before any flies had emerged, and kept 
in a room. The braconids commenced to appear from them on 
May 29. 
