Economic entomology for the farmer Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; economicentomolo00smit Year: 1906 340 AN ECONOMIC ENTOMOLOGY. Imc. ^S''^- on the jjrape, 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, modifications of farm practice, since they are usu- ally beyond the reach of insecticide substances. T
Economic entomology for the farmer Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; economicentomolo00smit Year: 1906 340 AN ECONOMIC ENTOMOLOGY. Imc. ^S''^- on the jjrape, 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, modifications of farm practice, since they are usu- ally beyond the reach of insecticide substances. This closes the series of long-horned, mosquito-like 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 antennae, 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 BibionidiS, 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 service in pollen- izing. ' Black flies,' or 'gnats,' are in some localities serious pests to man and domestic animals. The 'black flies' of the North- ern woods and the 'buffalo-' and ' turkey-gnats' of the South- ern and Mississippi States are good examples. They are rather b Bibio alhit>ennis.—a, male; c, its head; b, W- male; rf, lier head ; e, f, g, other structural details.
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