418 Asilidce 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, 3), 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 nearlj- 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. Jt belongs to the same 

 genus, possessing all the generic characters already pointed 

 out. It is 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' 

 become numerous must prove a formidable enemy to the 



