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See also:ORTHOPTERA (Gr. Op®os, straight, and rTepov, a wing) , a See also:term used in zoological See also:classification for a large and important See also:order of the class See also:Hexapoda. The cockroaches, grasshoppers, crickets and other See also:insects that are included in this order were first placed by C. Linne (1735) among the See also:Coleoptera (beetles), and were later removed by him to the See also:Hemiptera (bugs, &c.). J. C. See also:Fabricius (1775) was the first to recognize the unnaturalness of these arrangements, and founded for the reception of the See also:group an order Ulonata. In 18o6 C. de Geer applied to these insects the name Dermaptera (SEpµa, a skin, and srrepov) ; and A. G. See also:Olivier subsequently used for the assemblage the name Orthoptera, which is now much better known than the earlier terms. W. See also:Kirby (1815) founded an order Dermaptera for the earwigs, which had formed See also:part of de Geer's Dermaptera, accepting Olivier's term Orthoptera for the See also:rest of the assemblage, and as See also:modern See also:research has shown that the earwigs undoubtedly deserve See also:original separation from the cockroaches, grasshoppers, crickets, &c., this terminology will probably become established. W. E. Erichson and other writers added to the Orthoptera a number of families which Linne had included in his order See also:Neuroptera. These families are described and their See also:affinities discussed in the articles NEUROPTERA and HEXAPODA (qq.v.). In the See also:present See also:article a See also:short See also:account of the characters of the Dermaptera and Orthoptera is given, while for details the reader is referred to See also:special articles on the more interesting families or See also:groups. The Dermaptera and the Orthoptera agree in having well-See also:developed mandibles, so that the jaws are adapted for biting ; in the incomplete See also:fusion of the second maxillae (which See also:form the labium) so that the parts of a typical maxilla can be easily made out (see the description and figures of the cockroach's jaws under HExAroDA); in the presence of a large number of excretory (Malpighian), tubes; in the See also:firm texture of the forewings; in the presence of appendages (cerci) on the tenth abdominal segment; and in the See also:absence of a See also:metamorphosis, the See also:young See also:insect after hatching closely resembling the See also:parent. Order Dermaptera. In addition to the characters just enumerated, the Dermaptera are distinguished by the presence of small but distinct maxillulae (fig. 2, see HEXAPODA, See also:APTERA) in association with the See also:tongue (hypopharynx) ; by the forewings when present being modified into short quadrangular elytra without nervuration, the complex See also:hind-wings (fig. i) being folded beneath these both longitudinally and transversely so that nearly the whole See also:abdomen is See also:left uncovered; and by the entirely mesodermal nature of the genital ducts, which, according to the observations of F. Meinert, open to the exterior by a median See also:aperture, the terminal part of the duct being single, either by the fusion of the See also:primitive paired ducts or by the suppression of one of them. In the vast See also:majority of winged insects the terminal part of the genital See also:system (vagina and ductus ejaculatorius) is unpaired and ectodermal. Thus the See also:condition in the Dermaptera is more primitive than in any other Pterygote order except the Ephemeroptera (Mayflies) which are still more generalized, the primitive mesodermal ducts (oviducts and See also:vasa deferentia) opening by paired apertures as in the See also:Crustacea. In the vast majority of the Dermaptera the cerci are—in the adult insect at least—stout, unjointed appendages forming a strong forceps (fig. 1) which the insect uses in arranging the hindwings beneath the elytra. In at least one genus the unjointed pincers of the forceps are preceded, in the youngest instar by jointed cerci. Very many members of the order are entirely wingless. There are two families of Dermaptera. The Hemimeridae include the single genus See also:Hemimerus (q.v.), which contains only two See also:species of curious wingless insects with See also:long, jointed cerci, found among the See also:hair of certain See also:West See also:African rodents. The other See also:family is that of the Forficulidae or earwigs (q.v.), all of which have the cerci modified as a forceps, while wings of the characteristic form described above are present in many of the species. Order Orthoptera. The bulk of de Geer's " Dermaptera " form the order Orthoptera of modern systematists, which includes some lo,000 described species. The insects comprised in it are distinguished from the earwigs by their elongate, rather narrow forewings, which usually See also:cover, or nearly cover, the abdomen when at rest, and which are firmer in texture than the hindwings. The hindwings have a firm costal See also:area, and a more delicate anal area which folds fanwise,so that they are completely covered by the forewings when the insect rests. Rarely (in certain cockroaches) the hindwing undergoes transverse folding also. Wingless forms are fairly frequent in the order, but their relationship to the allied winged species is evident. The See also:female of the See also:common cockroach (fig. 3a) shows an interesting vestigial condition of the wings, which are but poorly developed in the male (fig. 3b). More important characters of the Orthoptera than the nature of the wings—characters in which they differ from After Marlatt, Ent. See also:Bull. 4, n. s. U.S. Dept. Agr. the Dermaptera and agree with the vast majority of winged insects—are the absence of distinct maxillulae and the presence of an unpaired ectodermal See also:tube as the terminal region of the genital system in both sexes. The cerci are nearly always joined, and a typical insectan ovipositor with its three pairs of processes is present in connexion with the vagina of the female. In many Orthoptera this ovipositor is very long and conspicuous (fig. 5). See also:Information as to the See also:internal structure of a typical orthopteron—the cockroach—will be found under HEXAPODA. Classification.—Six families of Orthoptera are here recognized, but most special students of the order consider that these should be rather regarded as super-families, and the number of families greatly multiplied. Those who wish to follow out the classification in detail should refer to some of the See also:recent monographs mentioned below in the bibliography. There is See also:general agreement as to the See also:division of the Orthoptera into three sub-orders or tribes. I. Phasmidea.—This division includes the single family of the Phasmidae whose members, generally known as " stick-insects " (q.v.) and " See also:leaf-insects " (q.v.), are among the best-known examples of "protective resemblance " to be found in the whole See also:animal See also:kingdom. The prothorax is short and the mesothorax very long, the three pairs of legs closely similar, the wings often highly modified or absent, and the cerci short and unjointed. Each See also:egg is contained in a See also:separate, curiously formed, See also:seed-like See also:capsule, provided with a lid which is raised to allow the See also:escape of the newly-hatched insect. II. Oothecaria.—In this tribe are included Orthoptera with a large prothorax, whose eggs are enclosed in a common See also:purse or capsule formed by the hardening of a maternal secretion. The Mantidae or " praying insects " have the prothorax elongate and the fore-legs powerful and raptorial, while the large, broad See also:head is prominent. The eggs are enclosed in a See also:case attached to a twig or See also: Magnified. (q.v.) form the second a, See also:Side view; b, end view; the outline family of this division. c shows natural See also:size. They are readily dis- tinguished by the somewhat rounded prothorax beneath which the head is usually concealed, while the forelegs are unmodified. Sixteen eggs are enclosed together in a compact capsule or " purse " (fig 4)• From See also:Carpenter's Insects. Dent & Co. C stridulating See also:organs which produce chirping notes (see See also:CRICKET). The families are the Acridiidae and Locustidae—including the insects familiarly known as locusts and grasshoppers (q.v.) and the Gryllidae or crickets (q.v.). The Acridiidae have the feelers and the ovipositor relatively short, and possess only three tarsal segments; their ears are situated on the first abdominal segment and the See also:males stridulate by scraping rows of pegs on the inner aspect of the hind thigh, over the See also:sharp edges of the forewing nervures. The Locustidae (see See also:GRASSHOPPER, See also:KATYDID) have the feelers and often also the ovipositor very elongate; the See also:foot is four-segmented; the ears are placed at the See also:base of the foreshin and the stridulation is due to the See also:friction of a transverse " See also:file " beneath the base of the left forewing over a sharp See also:ridge on the upper aspect of the right. In some of these insects the wings are so small as to be useless for See also:flight, being modified altogether for stridulation. The Gryllidae (fig. 5) are nearly related to the Locustidae, having long feelers and ovipositors, and agreeing with the latter family in the position of the ears. The forewings are curiously arranged when at rest, the anal region of the wing lying dorsal to the insect and the rest of the wing being turned downwards at the sides (see CRICKET). Fossil See also:History.—The Orthoptera are an exceedingly interesting order of insects as regards their past history. In Palaeozoic rocks of Carboniferous See also:age the researches of S. H. Scudder have revealed insects with the general aspect of cockroaches and phasmids, but with the two pairs of wings similar to each other in texture and form. In the Mesozoic rocks (Trias and See also:Lias) there have been discovered remains of insects intermediate between those See also:ancient forms and our modern cockroaches, the differentiation between forewings and hindwings having begun. The Orthopteroid type of wings appears therefore to have arisen from a primitive Isopteroid condition. Additional information and CommentsThere are no comments yet for this article.
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