Gr. S. CtRAHAM-SmITII 
529 
From these 17 flies (16 blow-flies and 1 small fly) had emerged, 74 
puparia contained shrivelled or putrifying fly remains, 180 braconids 
had emerged, 7 puparia contained dead braconids, 349 showed pin-holes 
and contained dead chalcids, and 344 were whole and contained living 
chalcid larvae. In this box therefore 19-2 % of the pupae were 
parasitised by braconids, and 71-3 % by chalcids. 
D. From this “box” a batch of pupae were transferred on April 29 
to the “shade tin” and kept in a separate jar. This jar contained 
47 puparia. From these one blow-fly and a living braconid emerged, and 
of the 45 remaining puparia 5 contained shrivelled fly larvae, 1 contained 
a dead braconid and 39 contained living braconid larvae 1 . 
Fig. 13. Larva of A. manducator ( x 6 and nat. size) removed from a puparium of C. 
erythrocephala. 
Fig. 14. Chalcid larva ( x 20 and nat. size), probably M. acasta, removed from a puparium 
of C. erythrocephala. 
In this jar therefore 87 % of the pupae were parasitised by braconids. 
The reason for the retardation in the development of these parasites 
is not clear. 
The last two observations confirm the view that the chalcid infection 
occurred after April 29, and further it seems justifiable to conclude 
from these four experiments that the chalcids only frequent warm or 
sunny places. The extent of autumnal infection with braconids, un¬ 
complicated by subsequent chalcid infection, in the two tins is shown 
by the results of the examination of the puparia in the “shade box,” 
1 Of these 39 puparia 21 were examined and contained braconid larvae. The remaining 
18 probably also contain them and have been kept in order to observe further develop¬ 
ments, if any. One opened on June 2, 1916 contained a recently formed braconid pupa. 
