284 



PRAIRIE COMMUNITIES 



sometimes taken. The slender meadow grasshopper (Xiphidium fascia 

 taum) is common, but breeds in the sedge zone. A flea-beetle (Monachus 

 saponatus), the 12-spotted Diabrotica (Diabrotica 12-pundata) (156), 

 and the salt-meadow snout-beetle (Endalus limatulus) (156) are the 

 chief beetles. 



The spiders (Epeira trivittata and Tetragnatha laboriosa) are common. 



The flies of this girdle are perhaps the most noteworthy insects. Several 



species of brownish or yellowish flies with conspicuously marked wings 



are nearly always common. They are Sciomyzidae (Tetanocera plumosa 



and umbrarum) (Fig. 283). Other characteristic 



flies are Osinidae (Chlorops sulphur ea Leow.), 



midges, mosquitoes, Dolichopodidae,Drosophilidae, 



and Anthomyidae. The blue and yellow moth 



(Scepsis fulvicollis) is common. 



Boneset and sedge girdle: The buffalo tree- 

 hopper (Ceresa bubalus) (Fig. 259) is found here. 

 The dusky (Fig. 261) and tarnished plant-bugs 

 (Fig. 262) suck the juices of the mint and other 

 plants. The ambush-bug and the damsel-bug 

 often lie in wait in the blossoms for prey. 



290 



Fig. 290. — Larva of the salt-marsh caterpillar (Estigmena acraea Dru.); natural 

 size (after Forbes). 



Fig. 291. — Adult female of the same; natural size (after Forbes). 



Aphids occur and with them are the syrphus flies, lady-beetles, 

 and other aphid enemies (164), which are discussed more fully in 

 connection with high prairies. The bright green beetle [Chrysochus 

 auratus) feeds on the small-leafed milkweed. One of the corn "bill- 

 bugs" (174) or snout-beetles {Sphenophorus pertinax Oliv.), another 

 snout-beetle (Cryptocephalus venustus), common garden pests, as well as 

 the leaf-beetle (Typophorus canellus) are common (174). 



One of the most characteristic groups of the low prairie is that of the 

 grass-feeding larvae. The first of these to appear in spring is the grass 



