THE INSECT WORLD. 



347 



of fact it is predaceous in habit, and feeds upon the species 

 really infesting carpets and similar material. Thus, ' ' moths, ' ' 

 the larvae of the ' ' carpet-beetle, " " fish-moths, ' ' and numerous 

 other insects likely to 

 occur in such situa- 

 tions are destroyed by 

 it. From this larva 

 there comes in due 

 time a small blue fly, 

 a member of the family 

 Scenopinidce ^ slender 

 and somewhat flattened 

 in appearance, with yel- 

 low or reddish legs, and 

 this may be sometimes 



seen upon the win- Scenophms fcnestralis. 



dows. These larvse 



have been often brought to me, and the little flies raised from 

 them have always been Scenopinus fenestralis, from which Pro- 

 fessor Comstock gives the group the name "window-flies." 



The remainder of the Diptera have the antennse short, rarely 

 more than three-jointed, and usually with a bristle or style, called 

 an "arista," which may or may not be feathered or plumose, 

 from the second or third joint. The first of the families to which 

 it is necessary to refer here is the Syrphidcs, containing a large 

 number of species, most of them prettily colored, yellow, black, 

 or bronze, patterned and marked in many different ways. They 

 frequent flowers, hovering and often remaining suspended over 

 them in mid-air for some time, then suddenly darting away and 

 again returning. Their habits and appearance frequently give 

 them a resemblance to bees and wasps, and in some species this 

 is carried so far that they are easily mistaken for members of the 

 order Hyme^ioptera by those not familiar with them. As a rule, 

 ^ the head is quite large, the body barrel-shaped, and the abdomen 

 a little flattened, varying from very slender to broadly oval in 

 shape. This abdomen is yellow and black, or bronze banded, 

 sometimes entirely bronzed, more rarely blue or green, but 

 nearly always brightly colored in some way. Some of the flies 

 have the body distinctly covered with hair, though generally this 



