FLIES, MOSQUITOES, AND MIDGES 239 



they may well be regarded with suspicion. One species occasionally 

 attacks the roots of corn, and another, the beet leaf-miner, makes 

 tortuous mines in beet leaves. 



The fruit-flies (Trypetidae) burrow in the flesh of fruits and in 

 the stems of plants. The common round gall on the golden-rod is 

 caused by the maggot of one of this group, most of which are 

 medium-sized flies, often metallic in color and usually with strik- 

 ingly banded or mottled wings. In New England the common 

 apple-maggot (Rhagoletis pomonella), or "railroad worm," which 



\ 



FIG. 380. A pomace-fly (Drosophila ampelophila), (Enlarged) 



a, adult ; b, antenna of same ; c, base of tibia and first tarsal segment ; d, e, puparium 



from side and above ; /, larva ; g, anal spiracles of same. (After Howard, United States 



Department of Agriculture) 



bores through the flesh of the apples, is a well-known example, the 

 adult being black and white with black-banded wings. In Mexico 

 a similar species infests the orange and is occasionally imported 

 into this country. The little pomace-flies (Drosophila sp.), small, 

 yellowish flies about one eighth of an inch long, are common about 

 cider mills and wherever there is decaying fruit, in which their 

 maggots develop. 



II. PUPIPARA 



This suborder includes three parasitic families, with but few 

 species, so named on account of the peculiar mode of reproduction. 

 The eggs and larvae are developed within the body of the female 

 and are given birth when mature and all ready to pupate. 



