Gr. S. GrRAHAM-SMITH 
361 
separate tube. On April 25 2 A Dibrachys cavus emerged from 1 puparium. 
Between May 6 and 19 G <? and 96 $ M. acasla developed in 12 puparia. 
Another contained living chalcid larvae and two others dead fly larvae (for 
details see 1916, p. 543). 
On June 10, 1916, 13 puparia were placed in a jar in this room and M. acasta 
commenced to emerge 9 days later. In 11 of these puparia 18^ and 201 $ 
developed. 
From the 341 puparia kept in the cooler room B M. acasta commenced to 
emerge at the end of July. In 117 puparia 114 c? and 1613 $ M. acasta de¬ 
veloped and D. cavus in 9. Six puparia were dissected at various times, and 
no parasites emerged from the remaining puparia, which were kept under 
observation for a year and dissected in April 1917. In 101 of these dead 
specimens of M. acasta were found, in 25 living or dead larvae of A. manducator 
and in 83 dead fly larvae or pupae. 
Fig. 10. Melittobia acasta £ . X 20. 
Fig. 11. Melittobia acasta $. X 20. 
These observations show that the emergence of M. acasta is greatly 
hastened by warmth, and that this parasite, when it attacks puparia already 
parasited by A. manducator , may emerge from fly puparia nearly two years 
old. 
It is of interest to note that of the 370 puparia remaining intact after one 
year’s observation 242 or 65 per cent, yielded living or dead adults or larvae 
of M. acasta. Living chalcids, 138 <? and 1925 ?, developed in 140 of the 
puparia, giving a mean of 1 <? and 13 $ in each puparium. The mean number 
emerging from each puparium is small, and this is due perhaps to the fact that 
all the puparia were previously infected by A. manducator. 
Similar observations were made with very large numbers of fly puparia 
kept under identical conditions during the winters 1915-16 and 1916-17. In 
the former year only one puparium infected with M. acasta (1 $ and 7 ?) was 
observed, and in the latter none. In both years, however, severe infections 
with other chalcids occurred. 
