THE GRASS STEM FLIES 



(Family Oscinidcz.) 



These are little flies, either dark and shining or yellowish in 

 color, and are more or less stout-bodied. The larvae breed in the 

 stems of grasses or are found in decaying vegetable material; 

 some live in the burrows or cavities in plants made by other 

 insects while a few feed on the egg shells and cast skins of 



Fig. 105. — Hippelates plebejus. 



insects. Meromy^a americana feeds in the stems of wheat and 

 rye, and sometimes does considerable damage; the larva of 

 Chlorops graminea lives in a gall-like swelling on grass stems, 

 and the larva of Chlorops assimilis mines the leaves of sugar beet. 

 One of the commonest of these flies in this country is a little 

 scavenger known as Gaurax anchora, which feeds upon all sorts 

 of dead animal matter, such as the empty egg shells of other 

 insects, the cast-off skins of caterpillars and chrysalids, and 

 spiders' eggs. The little flies of the genus Hippelates are 



183 



