192 | Psyche [December 
development which was then termed a “‘semi-pupa.”’ It is doubt- 
ful if larvee assuming this state ever successfully develop into 
adults. 
The accompanying illustration shows the dorsal view of the 
glossy, brown larve (enlarged five diameters) a lateral view of the 
semi-pupa or prothetelic state (four diameters), and a natural size 
view of the first lot of larve. 
ASILIDS AND THEIR PREY. 
By Stantey W. BrRoMLey, 
Southbridge, Mass. 
While collecting insects during the summers of 1912-13 at 
Southbridge, Mass., I was attracted by the predaceous habits of 
certain Asilidee and the apparent partiality of some of the species 
for Hymenoptera, while others, as for example, Asilus sericeus, 
would almost invariably seize a Lepidopterous insect. ‘To ascer- 
tain more fully the feeding habits of the species, I made a special 
collection of Asilidze with their prey. 
Asa Fitch in his Ninth Report, page 251, pl. 4, fig. 7, refers to 
what is now called Promachus fitchii O. S., as the “Nebraska 
Bee-killer”—Trupanea apivora, stating that he had received it 
from Nebraska where it was destructive to the honey bee and also 
to the rose bug. Astorobber-flies killing bees, I have not seen them 
do much damage, but I have never observed them closely in the 
vicinity of hives. Most of the bees taken were in the field, prob- 
ably at quite a distance from any apiary. They might, however, 
become injurious if abundant near a hive, for they always capture 
their prey on the wing and would undoubtedly seize indiscrimin- 
ately any bee that came within their range. As the various species 
of Vespa and other Hymenoptera were more plentiful in the fields 
than the honey bee, these fell victims to the ravenous appetites of 
the Asilids which preyed also on members of their own family and, 
indeed, even on those of the same species. 
As far as my observations go, there are very few insects that 
will attack robber-flies. I have seen a species of Crabro sting and 
