358 Parasites of Common Flies 
Only a single parasite emerged from an infected puparium, and in all the 
cases observed the puparium was a small one. The opening through which 
the parasite emerges is irregular (PL XIX, figs. 7, 9). 
Experimentally this parasite was seen to oviposit over a period of 4 or 
Fig. 5. Trichopria sp. x 20. 
5 days. From ova deposited in September 1916 in very small larvae confined 
in tubes, imagines appeared in June and July 1917. 
It will be noticed that all the three species observed passed the winter in 
fly puparia. 
