OCR Text |
Show 522 INSECTA. females is terminated by a tubular and horny ovipositor. These Insects produce a small sharp sound by the rubbing of the pedic1e of the base of their abdomen against the interior of the parietes of the thorax. In the system of Linnreus, these Insects form three genera, Cerambyx, Leptw·a and Necydalis, which Geoffroy, Fabri. cius, and other naturalists have endeavoured to regulate and simplify by the transposition of species, or by · establisl1ing other generic sections. If we consider the number of spe. cies that have been discovered since the time of the Pliny of theN orth, the insufliciency of the characters which designate these genera, and the eonfusion which still exists in severalof them, it will be plain that a general and elaborate revision has beeome necessary-let us hope that the researches of Messrs Lepeletier and Serville, who have paid particular attention to this family, will remove these difficulties. We will in the first place divide the Longicornes into two sections. In those of the first, the eyes are either strongly emargi· nated or lunate, or elongated and narrow; the head is plunged into the thorax, as far as those organs, without being distin· guished from it by an abrupt contmction of its diameter, form· ing a kind of neck; in several it is vertical. In some, the last joint of the pal pi is sometimes almost in the form of a cone or reversed triangle, and sometimes nearly cylindrical and truncated at the extremity. The lobe termi· nating the maxillre is straight, and not curved on the inner one at its end. The head usually projects or is simply in· clined, and in those, where, by a. very rare exception-the Dorcaceri-it is vertical, its width is nearly equal to that of the body, and the antennre are very remote at base and spin· ous. The thorax, frequently unequal or square, is rarely cylindrical. These Longicornes are subdivided into two principal sec· tions or small tribes. 1. The PRIONII, characterized as follows: the labrum null or very small and indistinct; the mandibles stout, or even very COLEOPTERA. 523 large, particularly in most of the males; the internal lobe of the maxillre null or very small; the antennre insePted near the base of the mandibles or the cmargination of the eyes, but not surrounded by the latter at base ; the thora.· most ft·cquent1y trapezoidal or square, crenated or dentated laterally. The first genus, or PARANDRA, Lat.-.llttelabus, De Geer,-Tenebrio, Fab., Where, as in the following, the antenn~ arc simple, almost granosc, compr·csscd, of equal thickness throughout, and as long as the thorax at most, and the terminal lobe of the maxillre is very small, scarcely reaching to the extremity of the first joint of the palpi, is distinguished from that genus( 1 ), as well as from all other·s of the same family, by its corneous ligula, which is in the form of the segment of a very short, transversal circle without emargination or Jobes, and by its tarsi, the penultimate joint of which is slightly bilobate, and the last, much longer than the p1·cccding ones taken together·, presents between its hooks a little appendage with two terminal sctce. The body is a parallelopipad, and depressed, ami the thorax square, rounded at the posterior angles, and without spines or teeth. These Insects are peculiar to America(2). SPONDYLIS, Fab.-.llttelabus, Lin.-Cerambyx, De Geer. The Spondylcs, which approximate to the Parandrce in their autennce and the exiguity of their maxillary lobes, are removed from them by theit· ligula; the latter, as in all the following Longicor·nes, is membranous and cordiform. They also differ in the tarsi; the penulti· mate joint is deeply bilobate, and the last is not longer than the pt·eceding ones taken together, and is without an appendage bearing two setce between the hooks. The Spondyles are also distinguished f1·om the following gcner·a by their almost globular thorax, the margin of which is neithct• recurved nor furnished with teeth ot· spines. Their larvce live in the interiot· of the European Pines and Firs. S. buprestoides; .llttelabus buprestoides, L.; Oli v. Col. IV, 71, i, 1. From six to seven lines in 'length; black; densely punctured, with two elevated and longitudi?al lines 'on each elytron. (1) The mandibles of the Spondyles and Pnrandrre are, at most, as long as the head, triangular or conical and arcuated at the end. · (2) Sec Lntr., Gencr. Crust. et Insect., Ill, 28, ancli, ix, 7; Schrenh., Synon. Insect., I, iii, p. 334, and App., p. 145, and Encyc . .Method., article Parandre. |