140 



AX ECO XO MIC EXTOMOLGGY 



Fig 



on the grape, and not improbably other species occasionally 

 found in leaf-galls are predatory upon the original producer. As 

 a whole, the gall-midges are to be regarded as dangerous, and 

 the measures to be adopted against them are. in almost all im- 

 portant cases, modihcations of farm practice, since they are usu- 

 ally beyond the reach of insecticide substances. 



This closes the series of long-horned, mosquito-hke flies, none 

 of which are of direct benefit to the farmer, while not a few are 

 among his most dangerous foes. As a whole, the species should 

 be looked upon with suspicion and closely investigated when 

 they occur in numbers great enough to attract attention. 



Quite early in the season we may see large numbers of loose- 

 jointed, ungainly flies of moderate size, with long, stout legs, 

 heavy body, short, stout, though many-jointed antenns, and 



often, in the female, a ridic- 

 ulously small head. In 

 color they are black, or 

 black and yellow, or red. 

 These belong to the family 

 BibionidcB, sometimes 

 called ' ' March-flies, ' ' from 

 their early appearance ; and 

 while their larvaE: are some- 

 times feeders on grass roots, 

 they ne\'er become eco- 

 nomically important. They 

 are mentioned here because 

 their early appearance in 

 great numbers sometimes at- 

 tracts attention. They are 

 often plentiful in orchards 

 just when the blossoms 

 open, but seem not to be 

 of any serxice in pollen- 

 izing. 



some localities serious pests 

 "black flies" of the North- 



Bibio albi_pe?mts.—a, male 

 male ; d, her head ; e, f. ^ 

 details. 



:, its head ; b, fe- 

 other structural 



" Black flies,"' or " gnats," are in 

 to man and domestic animals. The 

 ern woods and the "buttalo-" and "turkey-gnats" of the South- 

 ern and Mississippi States are good examples. They are rather 



