378 
Parasites of Common Flies 
and dry the larvae due to produce imagines in the autumn may have been 
killed, and the single experiment is not conclusive. 
Fly puparia collected in the autumn of 1916 from a sunny situation were 
kept under observation throughout 1917 with the following results: 
A. manducator A. cephalotes 
Flies ,--s ,- * -^ 
Puparia emerged Dead flies* Spring Autumn Dead* Larvae* Living Dead* 
3245 230 1351 384^+379 ? 51^+21$ 681 2 20 8 
N. brevicornis 
^ _A_ 
Living Dead* Larvae* Figitids 
69 15 28 6 
* The puparia remaining intact were dissected nearly a year later. 
In 1917 the spring was very cold until the end of April, but after that 
date the weather was very hot, and possibly it was due to this that so many 
of the fly nymphs and braconid larvae died. 
In this instance as in 1916 the great majority (90 per cent.) of the specimens 
of A. manducator which emerged did so in the spring. Of the fly puparia at 
least 1565 (48 per cent.) were infected with A. manducator, namely 1518 in 
which the braconid was found and 47 secondarily infected by N. brevicornis . 
At various times during the summer months of 1916 4280 puparia were 
collected from animal remains, and from these both the flies and their parasites 
emerged during the same season. 
Flies Dead 
Puparia emerged flies 
A. manducator 
Emerged Dead Larvae 
A. cephalotes Figitids Chalcids 
4280 2996 506 151 ^+99$ 77 11 3738 from 415 puparia 25 0 
Only 8 per cent, of these puparia were infected with A. manducator. 
