G. S. Graham-Smith 
381 
This experiment shows that unfertilised females oviposit readily, and that 
large numbers of males only are produced. As noticed in all other cases there 
were two distinct periods of emergence. 
From larvae first attacked by A. cephalotes and subsequently by A. 
manducator only A. cephalotes emerged. 
A. manducator were never seen to attack larvae feeding on faecal material. 
Aphaereta cephalotes Hal. 
Numerous specimens of A. cephalotes have been reared from naturally 
infected puparia kept throughout the winter in glass jars. About 10 adults 
in the proportion of 2 d to 8 $ emerge from the larger puparia. This parasite 
usually begins to emerge from over wintered puparia at the end of April and 
continues to emerge throughout May. There is no autumn batch such as 
occurs in the case of A. manducator. 
Fig. 21. Aphaereta cephalotes $. X 10. 
Out of 4742 puparia from a sunny situation kept under observation in the 
winter 1915-16, 314 (6 per cent.) were infected with A. cephalotes and pro¬ 
duced 2496 individuals, whereas of the 5163 puparia from a shady situation 
only 32 (0*6 per cent.) were infected with A. cephalotes. 
A. cephalotes seems to be afraid of the larger larvae and can hardly be 
induced to attack them even when no other larvae are present, but it oviposits 
very readily in small fly larvae. The procedure of the parasite when ovipositing 
resembles that of A. manducator , but the ovipositor is inserted for a much 
longer period, in one case as long as 7 minutes, and the larvae remain motion¬ 
less longer, up to 30 minutes. 
