24 BULLETIN 621, IT. S. DEPARTMENT OP AGRICULTURE. 



Of the true bugs (Heteroptera), members of the stinkbug family 

 (Pentatomidse) are most frequently found. These strong-smelling 

 insects occurred in a large number of stomachs, though seldom in 

 great quantities. Inasmuch as some insects of this family are pre- 

 dacious, others herbivorous, and still others of varied food habits, 

 an indiscriminate feeding on them would result in no great harm or* 

 good. Podisus, Euschistus, and Brochymena were the genera most 

 frequently found. Assassin bugs (Reduviidae) are not uncommon 

 articles of food. Among those identified were the wheel bug (Pri- 

 onidus cristatus), two species of Melanolestes, Apiomerus crassipes, 

 and &inea sp., all of which are predacious. Of the Lygaeidae, the 

 notorious chinch bug (Blissus leucopterus) only is worthy of men- 

 tion. A crow collected in Kansas in November had eaten 30 of these 

 pests. 



Diptera (flies). 



Flies form a very small and, on the whole, unimportant part of 

 the crow's food, constituting less than half of 1 per cent. Of these, 

 craneflies (Tipulidae) are of greatest economic interest, as their 

 larva?, "leather- jackets," are destructive to grass lands. The adults, 

 pupae, larvae, and eggs of these insects have been taken from crows' 

 stomachs; the eggs, however, appearing in most cases to have come 

 from the bodies of females which the bird had eaten and partly 

 digested. Stomachs have been opened in which the contents were 

 blackened by many thousands of these minute ellipsoid eggs, when 

 only a trace of the fragile parent remained to tell the story whence 

 they came. Muscid and sarcophagid flies, their puparia and larvae — 

 the latter stages often associated with carrion — were present in many 

 stomachs, and in the case of some nestlings occurred in considerable 

 numbers. Marchflies (Bibionidae), horseflies (Tabanidae), robber- 

 flies (Asilidae), and soldierflies (Stratiomyidae) made up the hulk of 

 the remaining food classified under this order. 



Hymenoptera (ants, bees, icasps, etc.). 



Of the hymenopterous insects found in crows' stomachs, ants out- 

 numbered all other groups, but even they formed a negligible portion 

 of the diet, as all the Hymenoptera combined formed only about two- 

 thirds of 1 per cent of the yearly sustenance. In only one stomach 

 were ants present in considerable numbers, and in this several hun- 

 dred composed about three- fourths of the contents. Some of the 

 larger species eaten, as C amponotus herculeanus pennsylvanicus, and 

 some species of the genus Formica, probably are picked up by the 

 crow whenever met, but most of the smaller forms unquestionably 

 are eaten accidentally with carrion or dead insects over which they 

 swarm. In either case the quantity taken is so small that the eco- 

 nomic considerations involved are practically negligible. 



