œstridæ

Century Dictionary and Cyclopedia

1. A family of brachycerous dipterous insects, typified by the genus Œstrus; the bot-flies. They are mostly flies of rather large size, more or less hairy, of inconspicuous colors, with small mouth, rudimentary mouth-parts, small antennæ inserted in pits whence only the bristle projects, extremely narrow middle face, and very large tegulæ. About 60 species are known, all parasitic in the larval state upon vertebrates. With a single exception this parasitism is confined to mammals. The larvæ live in different places, in the nostrils and frontal sinuses, under the skin, and in the stomach and bowels; and each species usually confines its attacks to one kind of animal. Twenty-four species are found in North America. Œstrus (Gasterophilus) equi infests the horse; Œ. (Hypoderma) bovis, the ox; Œ. (Cephalomyia) ovis, the sheep. See bot-fly and Œstrus.