OCR Text |
Show 378 INSECTA. thorax, widest in the middle; the tibire are narrow, elongated b slightly widened at the end, and terminated by two ordinary s;ur~~ the elytra are obliquely truncated. ' Species of this subgenus are found in Europe, tropical America, the East Indies and New Holland( 1 ). Sometimes the body is oval or ovoid; the head, not at all or but very slightly strangulated posteriorly, and narrower than the thorax· the thorax either almost semicircular and truncated, or trapezoidal and wider behind; the elytra rounded or simply emarginated at the posterior extremity. There is but little or no difference in the pos· terior legs of the two sexes. The maxillre are armed internally with a tooth or squamous hook. SrLPHA, Lin. Fab.-Peltis, Geoff. The body almost scutiform and depressed, or but slightly elevated; thorax semicircular, truncated or very obtuse before; exterior margin of the elytra strongly recurved and canaliculated; palpi fiJi. form, their last joint almost cylindrical, and in several, terminating in a point. Most of them live in carrion, and thus diminish the quantity of its noxious effluvia. Some climb on plants, and parti· cularly on the stems of Wheat, where they find little Helices on which they feed. Others remain on high trees and devour cater· pillars. The larvre are all equally active, live in the same manner, and frequently in large societies. They bear a great resemblance to the perfect Insect. Their body is flattened, and consists of twelve segments, with acute posterior angles; the posterior extremity is narrower and terminated by two conical appendages. In most of the species, the two anterior tarsi of the males are alone more eli] a ted than the others. The antennre insensibly enlarge or terminate abruptly in a club of four joints at most, the second and third of which differ but little; the last joint of the maxillary palpi is, at most, as long as the penultimate, and frequently some· what shorter and more slender. Those species in which the extremity of the antennre is distinctly perfoliaceous or composed of joints, which, the last excepted, are wider than they are long, where this club is abrupt, and the elytra are emarginated at their extremity, at least in the males, form the genus THANATOPHILus, Leach(2). (1) Silpha littoralis, Fab., Oliv., Col., II, i, 8, a, b, c;-S. surinamemia, Fab. Oliv., lb., 11;-S. lachrymosa, Schreib., Lin. Trans., VI, xx, 5;-8. indica, Fab., &c. (2) Silpha ainuata, Fab.; Oliv., lb., II, 12;-S. dispar, Illig., Gyllenh., &c. COLEOPTERA. 379 Those, in which the elytra are entire, but where the antennre are similar to those of the preceding, constitute his OroEPTOMA. S. tlwracica, L.; Fab.; Oliv., Col. II, 11, i, 3, a, b. Black; thorax red and silky; three flexuous elevated lines on each elytron, the exterior shortest, forming a carina, and terminating near a transverse tubercle; posterior extremity of the elytra, in the males, terminating in a point at the suture. In the woods particularly. S. quad1·ipunctata, L.; Fab.; Oliv., lb., I, 7, a, b. Black; margin of the thorax and elytra yellowish, each of the latter with two black dots, one at base ar.d the other in the middle. Peculiar to forests, but usually remains on young Oaks, where it feeds on caterpillars(!). Those in which the extremity of the antennre is likewise perfoliaceous, but where the club is formed gradually, according to Leach, alone retain the generic appellation of 8ilpha. They are usually found in fields, along the roads, &c. S. lrevigata, Fab.; Oliv., lb., I, i, a, b. Shining black; multipunctured; thorax much narrower than before; elytra with· out elevated lines. S. obscura, L.; Fab.; Oliv., Ib., II, 18. Dusky black; thorax truncated anteriorly; elytra more deeply punctured; three raised but slightly salient and short lines, the intermediate the longe!>t, on each of the latter. S. reticulata, L.; Panz., Faun. Insect. Germ., V, g, Opaque black; thorax truncated before; three raised lines on each elytron, the exterior largest and forming a carina, terminated by a tubercle, with transverse rugre in the intervals(2). The antennre of some are not distinctly perfoliate at the extremity the last joints being almost globular. They are the PHOSPHUGA: Id.(3) A species from Germany, which might form a separate subgenus -NEoROPHILus, Lat.-is remo\'ed from the preceding ones by several characters. It is the S. subterranea, Illig., and others. The four anterior tarsi at·e similar and dilated at base, the two first joints, at least in the males, being evidently broader than the two following ones. The third joint of the antennre is longer than the preceding one, and the five last form abruptly a perfoliaceous club. The (l) Add, S. rugosa, Fab.; 01iv.~ II, Ib ., 17;-8. laponica, Fab. (:) Add, S. opaca, Fab.; Herbst., Col., LI, 16;-S. tristis, Illig., &c. (->) 8. atrata, Fab.;-S.pedemontana, ld., var.; Oliv., lb., I, 6. |