224 



DRY AND MESOPHYTIC FOREST COMMUNITIES 



by pollen-gathering insects (Andrenidae, Apidae, syrphus flies, etc.). 

 The kingbirds feed on these insects; one article of their diet, the robber- 

 flies, is always common. A chrysomelid beetle (Disonycha quinquevittata) 

 commonly feeds upon the willow. The cherry is attacked by aphids 



Fig. 186. — A robber-fly (Erax sp.); 3 times natural size (after Williston). 



Fig. 187. — Robber-fly {Pro- 

 tnachus vertebratus Say); natural 

 size (after Washburn from Willis- 

 ton). 



Fig. 188. — A bee-fly {Exoprosopa 

 sp.); 1 2 times natural size (from 

 Williston after Kellogg). 



which attract the Coccinellidae, and the syrphus flies. Cherries are 

 eaten by many birds. 



