1911 Encyclopædia Britannica/Grasshopper

GRASSHOPPER (Fr. sauterelle, Ital. grillo, Ger. Grashüpfer, Heuschrecke, Swed. Gräshoppa), names applied to orthopterous insects belonging to the families Locustidae and Acridiidae. They are especially remarkable for their saltatory powers, due to the great development of the hind legs, which are much longer than the others and have stout and powerful thighs, and also for their stridulation, which is not always an attribute of the male only. The distinctions between the two families may be briefly stated as follows:—The Locustidae have very long thread-like antennae, four-jointed tarsi, a long ovipositor, the auditory organs on the tibiae of the first leg and the stridulatory organ in the wings; the Acridiidae have short stout antennae, three-jointed tarsi, a short ovipositor, the auditory organs on the first abdominal segment, and the stridulatory organ between the posterior leg and the wing. The term “ grasshopper ” is almost synonymous with Locust (q.v.). Under both “grasshopper” and “locust” are included members of both families above noticed, but the majority belong to the Acridiidae in both cases. In Britain the term is chiefly applicable to the large green grasshopper (Locusta or Phasgonura viridissima) common in most parts of the south of England, and to smaller and much better-known species of the genera Stenobothrus, Gomphocerus and Tettix, the latter remarkable for the great extension of the pronotum, which often reaches beyond the extremity of the body. All are vegetable feeders, and, as in all orthopterous insects, have an incomplete metamorphosis, so that their destructive powers are continuous from the moment of emergence from the egg till death. The migratory locust (Pachytylus cinerascens) may be considered only an exaggerated grasshopper, and the Rocky Mountain locust (Caloptenus spretus) is still more entitled to the name. In Britain the species are not of sufficient size, nor of sufficient numerical importance, to do any great damage. The colours of many of them assimilate greatly to those of their habitats; the green of the Locusta viridissima is wonderfully similar to that of the herbage amongst which it lives, and those species that frequent more arid spots are protected in the same manner. Yet many species have brilliantly coloured under-wings (though scarcely so in English forms), and during flight are almost as conspicuous as butterflies. Those that belong to the Acridiidae mostly lay their eggs in more or less cylindrical masses, surrounded by a glutinous secretion, in the ground. Some of the Locustidae also lay their eggs in the ground, but others deposit them in fissures in trees and low plants, in which the female is aided by a long flattened ovipositor, or process at the extremity of the abdomen, whereas in the Acridiidae there is only an apparatus of valves. The stridulation or “song” in the latter is produced by friction of the hind legs against portions of the wings or wing-covers. To a practised ear it is perhaps possible to distinguish the “song” of even closely allied species, and some are said to produce a sound differing by day and night.