1911 Encyclopædia Britannica/Wireworm

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WIREWORM, a popular name for the slender, hard-skinned grubs or larvae of the click-beetles or Elateridae, a family of the Coleoptera (q.v.). These larvae pass a long life (two or three years) in the soil, feeding on the roots of plants, and they often cause much damage to farm crops of all kinds, but especially to cereals. A wireworm may be known by its broad, quadrate head and cylindrical or somewhat flattened body, all of whose segments are protected by a firm, chitinous cuticle. The three pairs of legs on the thoracic segments are short and the last abdominal segment is, as is frequently the case in beetle grubs, directed downwards to serve as a terminal proleg. The hinder end of the body is acutely pointed in the larvae of the species of Agriotes (A. obscurus and A. lineatus) that are the best knows of the wireworms, but in another common form (the grub of Athous haemorrhoidalis) the tail is bifid and beset with sharp processes. The subterranean habits of wireworms make it hard to exterminate them when they have once begun to attack a crop, and the most hopeful practice is, by rotation and by proper treatment of the land, to clear it of the insects before the seed be sown. Passing easily through the soil on account of their shape, wireworms travel from plant to plant and thus injure the roots of a large number in a short time. (See Economic Entomology.) Other subterranean creatures — such as the “leather-jacket” grub of crane-flies — which have no legs, and geophilid centipedes, which may have over two hundred, are often confounded with the six-legged wireworms.