278 THE HUMBLE-BEE 
Physocephala rufipes—Mr. E. E. Austen of the British 
Museum has kindly examined the pupa that developed 
from a large dipterous larva that I found inside the 
abdomen of a queen of JS. ¢errestris, stung to death on 
July 24, 1912, and has found it to belong to one of 
the Conopidz, “very probably to the species known as 
Physocephala rufipes, Fabr., which is parasitic in the 
abdomen of the imago of &. ¢errestris as well as in that 
of other species of Bombus. It appears that when the 
parasite reaches the final larval or pupal stage the host 
frequently, if not always, perishes.” The queen was one 
bred the previous year, and was taken with her nest, in 
which the first workers were about to hatch, on July 14. 
The day before she was killed I noticed that she was 
breathing at a slower rate than normal, and she had laid 
no eggs for at least two weeks. 
