418 Asilida or Robber Flies. 
is mostly concealed by the light yellow hairs, which are 
crowded thick about the mouth and between the eyes. 
The thorax is prominent and thickly set with light yellow 
hairs. The abdomen is narrow, tapering, and covered with 
yellow hairs except the tip, which is black. Beneath, the 
insect is clear black, though there are scattering hairs of a 
grayish yellow color on the black legs. The pulvilli, or 
feet pads (Fig. 201, 4), are two in number, bright yellow 
in color, surmounted by strong, black claws (Fig. 201, a), 
while below and between is the sharp spine (Fig. 201, c), 
technically known as the empodium. 
The habits of the flies are interesting, if not to our 
liking. Their flight is like the wind, and perched near the 
hive, they rush upon the unwary bee returning to the hive 
with its full load of nectar, and grasping it with their hard 
strong legs, they bear it to some perch near by, when they 
pierce the crust, suck out the juices, and drop the carcass, 
and are then ready to repeat the operation. A hole in the 
bee shows the cause of its sudden taking off. The evisce- 
rated bee is not always killed at once by this rude on- 
slaught, but often can crawl some distance away from 
where it falls, before it expires. 
Another insect nearly as common is Mallophora bom- 
boides, Weid. This fly might be called a larger edition of 
the one just described, as in form, habits, and appearance 
it closely resembles the other. It belongs to the same 
genus, possessing all the generic characters already pointed 
out. Itis very difficult to capture this one as it is so quick 
and active. : 
This fly is one and five-sixteenths inches long, and 
expands two and a half inches. The head and thorax are 
much as in the other species. The wings are very long 
and strong, and, as in the other species, are of a smoky 
brown color. The abdomen is short, pointed, concave from 
side to side on the under surface, while the grayish yellow 
hairs are abundant on the legs and whole under portion of 
the body. The color is a lighter yellow than in the other 
species. These insects are powerfully built, and if they 
a numerous must prove a formidable enemy to the 
ees. 
