ORTHOPTERAN

broadly, any member of one of four insect orders. Orthopteran has come to be regarded as the common name for these related groups, which exhibit considerable morphological, physiological, and paleontological diversity. Although sometimes the insects are combined into the order Orthoptera, generally several orders are implied in the term orthopteran. Female cockroach (Periplaneta) Among the orthopterans, cockroaches (see photograph) and mantids are placed in the order Dictyoptera; the grylloblattids (order Grylloblattodea) and walking sticks (order Phasmida) are given ordinal rank also. On the other hand, members of the suborders Ensifera (katydids, crickets, and camel crickets) and Caelifera (pygmy sand crickets, grasshoppers, and locusts) are considered to comprise the order Orthoptera. For completeness of discussion, all of these groups, handled here as four separate orders, are included in this article. Orthopterans, abundant in tropical regions throughout the world in both numbers of species and individuals, are common in the summer months in temperate regions, when their relatively large size and chirping sounds attract considerable attention. Zoologists have long been interested in cockroaches, one of the oldest insect groups known. Most of the 24,000 species of orthopterans are plant feeders, with mouthparts adapted for chewing. Locusts, known as pests since biblical times, are very destructive to agricultural products. broadly, a member of one of four insect orders: the Dictyoptera, which include the cockroaches and mantids; the Grylloblattodea or Notoptera, comprising some 15 species of icebugs; the Phasmida (also called Cheleutoptera, or Phasmatoptera), comprising the walking sticks and leaf insects; and the Orthoptera proper, including katydids, crickets, grasshoppers, and locusts. The confusion in the use of the term orthopteran reflects changes in the taxonomy of the various types over time. There are about 24,000 known species of orthopterans (in the broad sense). They range in size from a few millimetres to more than 30 centimetres and exhibit a great variety of forms. The largest orthopteran families are worldwide in distribution, although they are concentrated in tropical zones. Most are terrestrial in habit, living amid ground litter or burrowing into the soil. The oldest orthopteran fossils known are from the Carboniferous Period (about 280,000,000 to 345,000,000 years ago); they are of cockroaches that differ hardly at all from present-day species. The head of typical orthopterans is large and bears a pair of segmented antennae and a pair of compound eyes. They have strong mouthparts adapted to biting and chewing. The thorax bears three pairs of legs and two pairs of wings. The forewings are by far the larger and are usually elongated and leathery or parchmentlike. When folded they cover the hindwings, as well as most of the abdomen. Many species, however, are wingless. The abdomen of the females of most species ends in a long and conspicuous ovipositor, or egglaying organ. Except for the Grylloblattodea, all major groups of orthopterans contain species that produce sounds of one sort or another that play a role in mating as well as in aggressive behaviour. Crickets, grasshoppers, and katydids produce the most audible sounds by stridulation, which is the rubbing of pegs or serrations on one bodily appendage across ridges on another. Most orthopterans lay eggs, frequently arranged in an egg case. The larval or nymph forms resemble the adults except in their size, and there is no pupa stage. From 4 to 13 molts are typical before the adult form is attained. A few kinds of predatory orthopterans, such as mantids, help to control the population of undesirable insects. Many others, however, such as grasshoppers and locusts, may cause severe damage to crops as well as to natural vegetation. Cockroaches are chiefly household pests. Additional reading R.D. Alexander, Acoustical Communication in Arthropods, A. Rev. Ent., 12:495526 (1967), with many orthopteran examples; Life Cycle Origins, Speciation, and Related Phenomena in Crickets, Qt. Rev. Biol., 43:141 (1968), a valuable summary of modern advances in cricket biology; and with D. Otte, The Evolution of Genitalia and Mating Behavior in Crickets (Gryllidae) and Other Orthoptera, Misc. Publs. Mus. Zool. Univ. Mich., 133:562 (1967), well illustrated; E.D. Ball et al., The Grasshoppers and Other Orthoptera of Arizona, Tech. Bull. Univ. Ariz., 93:257373 (1942), well illustrated; W.S. Blatchley, Orthoptera of Northeastern America (1920), an important guide, some parts out of date; I.J. Cantrall, The Ecology of the Orthoptera and Dermaptera of the George Reserve, Michigan, Misc. Publs. Mus. Zool. Univ. Mich., 54:1182 (1943), a survey of 78 species of orthopterans; R.F. Chapman, The Insects: Structure and Function, 3rd ed. (1982), with many orthopteran examples; L. Chopard, Dictyoptres, Notoptres, Chleutoptres, and Orthoptres, in Trait de zoologie, vol. 9 (1949), a general treatise on Orthoptera; V.M. Dirsh, A Preliminary Revision of the Families and Subfamilies of Acridoidea, Bull. Br. Mus. Nat. Hist. (Ent.), 10:351419 (1961), the current classification of grasshoppers; The Post-Embryonic Ontogeny of Acridimorpha (Orthoptera), EOS, Madr., 43:413514 (1968), basic information on growth changes in grasshoppers; S.K. Gangwere, A Monograph on Food Selection in Orthoptera, Trans. Am. Ent. Soc., 87:67230 (1961), a summary of techniques for studying food preferences of orthoptera and a review of information on the food eaten by various orthopteran groups, chiefly U.S. species; A.B. Gurney, Praying Mantids of the United States: Native and Introduced, A. Rep. Smithson. Instn. for 1950, pp. 339362 (1951), a semipopular review with photos of several species; Daniel Otte, The North American Grasshoppers, 3 vol. (1981 ), a revision of the taxonomic order. D.M. Guthrie and A.R. Tindall, The Biology of the Cockroach (1968), emphasis on the physiology of cockroach species commonly used as laboratory animals; P.T. Haskell, Insect Sounds (1961), many references to orthoptera; M. Hebard, The Dermaptera and Orthoptera of Illinois, Bull. Ill. St. Nat. Hist. Surv., 20:125279 (1934), keys to species, illustrated; J.R. Helfer, How to Know the Grasshoppers, Cockroaches and Their Allies (1963, reissued 1987), a semipopular handbook; A.D. Imms, Imms' General Textbook of Entomology, 10th ed. rev. by O.W. Richards and R.G. Davies, 2 vol. (1977), an important but detailed text; F.A. McKittrick, Evolutionary Studies of Cockroaches, Mem. Cornell Univ. Agric. Exp. Stn. 389 (1964), classification of cockroaches; K. Princis, Blattariae, in Orthopterorum Catalogus, 8 pt. (196271), a catalog of living cockroaches, of use to researchers in systematics and distribution; D.R. Ragge, Grasshoppers, Crickets and Cockroaches of the British Isles (1965), a well-illustrated standard work; J.A.G. Rehn, Man's Uninvited Fellow Traveler, the Cockroach, Sci. Mon., 61: 265276 (1945), popular and factual; J.A.G. Rehn and H.J. Grant, A Monograph of the Orthoptera of North America (North of Mexico), vol. 1 (1961), detailed and authoritative; L.M. Roth, Oothecae of the Blattaria, A. Ent. Soc. Am., 61:83111 (1968), an illustrated review; The Evolution of Male Tergal Glands in the Blattaria, A. Ent. Soc. Am., 62:176208 (1969), a review.Evolution and Taxonomic Significance of Reproduction in Blattaria, A. Rev. Ent., 15:7596 (1970), a summary of reproductive habits; with T. Eisner, Chemical Defenses of Arthropods, A. Rev. Ent., 7:107136 (1962), concerned with secretory glands that produce repugnant substances; and with E.R. Willis, The Biotic Associations of Cockroaches (1960), a documented summary; A.G. Sharov, in Trans. Paleont. Inst., Moscow, 118:1208 (1968; Eng. trans., Phylogeny of the Orthopteroidea, pp. 1251, 1971), evolutionary development; B.P. Uvarov, Grasshoppers and Locusts, vol. 1 (1966), the first of a 2-volume book on this subject; T.J. Walker, Cryptic Species Among Sound-Producing Ensiferan Orthoptera (Gryllidae and Tettigoniidae), Q. Rev. Biol., 39:345355 (1964), emphasis on the large number of orthoptera species reproductively isolated by inconspicuous calling songs; F.E. Zeuner, Fossil Orthoptera Ensifera, 2 vol. (1939), a review with excellent illustrations. Ashley B. Gurney