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 33(^ AN ECONOMIC ENTOMOLOGY. Lt;gs and larva of J''.piilapHS scabei, mucli enlarged. that especial purpose. P'ortunately, the measures used to prevent the scab due to the fungous disease seem to destroy the insects as well ; hence the method of distinguishing between the two is not important. In the family Cecidoniyidce, containing the midges, or 'gall-gnats,' we find the most injurious species of the o
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 33(^ AN ECONOMIC ENTOMOLOGY. Lt;gs and larva of J''.piilapHS scabei, mucli enlarged. that especial purpose. P'ortunately, the measures used to prevent the scab due to the fungous disease seem to destroy the insects as well ; hence the method of distinguishing between the two is not important. In the family Cecidoniyidce, containing the midges, or 'gall-gnats,' we find the most injurious species of the order. They are also mosquito-like in appearance, but usually very small, with very long an- tennae, which in the males are clothed on each joint with whorls of fine hair. The larvae are ovate, quite broad, and a little flattened, the segments well marked, and the apparent mouth parts formed in many species by a peculiar horny pro- cess which is known as the 'breast- bone,' from its situ;ition. The species are numerous, and the larval habits and life histories are very diverse. In most cases growing vegetable tissue is the food, and, ao a rule, a more or less marked gall-like swelling indicates the location of the larva. The most widely known species is the 'Hessian-fly,' CcciJ- omyia dcsfnicior, one of the most serious enemies of wheat, actually inhibiting its cultivation in some localities. The adult is rather large for this family, smoky brown in color, and appears late in the season, usually after the wheat is well above ground. Eggs are laid on the young plants, and the larvae w^ork their way into the stem at or near the surface, causing a slight gall or swell- ing and a deformity in plant growth. When winter sets in full .'-ize has been reached, and the 'flaxseed' stage is entered upon,—so called because of its superficial appearance, though it is really the brown, dry, and hardened larval skin itself. In spring the pupa is formed, and soon afterwards the adult appears,
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