G. S. Graham-Smith 379 
In 1917 2188 fly puparia were collected on July 5 from similar situations. 
Flies Dead 
Puparia emerged flies 
A. manclucator 
Emerged Dead 
N. brevicornis 
Adults from 
Larvae in 
2188 1791 277 13 ^ + 17? 23 
59 8 
Only 2 per cent, of these puparia were infected with A. manducator. 
Of the 16,028 puparia collected in the autumns of 1914-15-16 from sunny 
and shady situations 7041 or 43 per cent, were infected with A. manducator , 
while of the 4787 puparia collected during the summer months of 1916-17 
only 508 or 10 per cent, were infected. 
These observations seem to indicate that infection with A. manducator is 
much greater in the autumn than during the summer. The parasite, however, 
is abundant throughout the season for it was observed attacking fly larvae 
from May 30 to November 1, 1916. 
Observations on the habits of A. manducator. 
Females were often kept under observation when depositing their eggs 
under natural conditions. The larger larvae seem to be selected for attack. 
The parasite seizes the larva with its legs, and in spite of the violent struggles of 
the victim, during which the pair turn over and over, seldom releases its hold. 
The struggle usually lasts several seconds. Finally the ovipositor is inserted 
and very soon afterwards the larva ceases to struggle, and remains motionless. 
The ovipositor remains inserted for 40-50 seconds, and is then withdrawn. 
After a period of one or two minutes the larva begins to move again and 
eventually regains full activity. As soon as the parasite leaves one larva it 
attempts to attack another. After a time it becomes battered and feeble and 
is only able to move slowly, owing to its struggles with a succession of larvae. 
The parasites usually seem to be able to secure a better hold on larvae 
moving towards them than on larvae moving away from them, for the former 
very seldom escape, while the latter occasionally do so. 
The ovipositor may be inserted into the anterior or posterior end of the 
larvae or more rarely into the middle. 
Sometimes the parasites walk over masses of large larvae, select several 
and oviposit in them. Occasionally they oviposit in larvae feeding under a 
thin shell of meat, driving their ovipositors through the shell and ovipositing 
without seizing the larvae. 
While males kept in confinement sometimes remain alive for 15 days, 
females confined with larvae, even though provided with places on which they 
can rest, invariably die in three or four days. 
Experiments with A. manducator. 
A large fertilised female A. manducator was put into a jar with 544 large 
fly larvae, chiefly C. erythrocephala. The parasite was found dead on the 
