OCR Text |
Show 340 INSECTA. of the thorax sinuous; undulated whitish streaks, formed b transverse hairs, on the elytra. Common on the Hazel, on th~ leaves of which it feeds. APHANISTious, Lat. The antcnnre suddenly terminated by a clavate, oblong, compress. ed, and slightly serrated club, formed by the four last joints; last joint of the palpi somewhat thicker and almost oval; space between the eyes excavated as in Trachys. Two or three species are known, all linear, and very small(!). Sometimes the antennre are strongly pectin a ted, on one side, in the males, and deeply securiform in the females; the joints of the tarsi are almost cylindrical and entire, the antennre terminated by one much thicker than those that precede it, and nearly ~lobular. The jaws terminate in a single lobe. MELASis, Oliv. The body cylindrical, and the posterior angle of the thorax pro. longed into an acute tooth, characters, which, like those drawn from the tarsi and palpi, announce that these Insects form the passage from this tribe to the second(2), Or that of the ELATERIDEs, which only differs essentially from the first in the posterior stylet of the prresternum, which terminates in a laterally compressed point, frequently somewhat arcuated and unidentate, that sinks at the will of the animal into a cavity in the pectus, situated immediately above the origin of the second pair of legs; and in the circumstance, that these Insects when placed on their back have the faculty of regain· ing their original position by bounding upwards. Most of them have mandibles emarginated or cleft at the end, palpi terminated by a triangular or securiform joint, much larger than those which precede it, arid the joints of the tarsi entire. This tribe only comprises the genus ELATER, Lin. The body is usually narrower and more elongated than that of the (I) Buprestis emarginata, l~ab.; Oliv., lb. X, 116; Germ., Faun. lnsect.Europ., Ill, 9;-Bup.lineola, ejusd., lb., 10. (2) Melasis buprestoide8, Oliv., II, 30, 1, 1 ;-Melasis elateroides, lllig., differing, aceording to him, from the Elater bupre8toides, Lin. COLEOPTERA. 341 Bu restides, and the posterior angles of the thorax are prolonged p . • h ~ f . · to a shat·p pomt, m t e 1orm o a spme. 10 The common French name of these Insects is Scarabees a ressort, and their Latin one, Notopeda, Elater. vVhen placed on their back, finding it impossible to regain theii· natural position on account of the shortness of their legs, they bound perpendicularly upwards until they fall on their feet. To execute this motion, they press the latter close to the body, lower theit· head and thorax, which has a free downward motion, then approximating this last to the postpectus, they forcibly press the point of the prresternum against the margin of the hole situated before the mesosternum, into which it sinks suddenly, as if by a spring. The thorax and its lateral points, the head and elytra, being violently propelled against the plane of position, particularly if it be solid and smooth, concur by their elas· ticity in causing the body to bound upwards. The sides of the prre· sternum are distinguished by a groove, where the antennre, which are pectinated or bearded in several males, are partly lodged. The females have a species of elongated ovipositor with two lateral pieces pointed at the end, between which is the true oviduct. The Elaterides are found on flowers, plants, and even on the ground; they lower their head in walking, and if any one approaches let themselves fail, pressing their legs against their body. De Geer has described the larva of a species (undulatus) of this genus. It is long, almost cylindrical, and provided with small an· tennre, palpi, and six feet; it consists of twelve annuli, covered with a scaly skin, that of the po~terior extremity forming a plate with an elevated and angular margin, with two blunt points curved inwards; underneath is a large fleshy and retractile mammilla, which performs the duty of a foot. It inhabits the debris of rotten wood, and is also found in the earth. It even appears that the larvre of the E. stria/us, Fab., attack the roots of the Wheat, and, where they exist in great numbers, do much injury to it. The stomach of the Elaterides is long, transversely rugose, and its posterior portion sometimes inflated; their intestine is moderate. The various subgenera of this tribe may be referred to two principal divisions. Those where the antennre can be entirely received into the inferior cavities of the thorax constitute the first. Sometimes they are received, on each side, into a longitudinal grbove, situated directly under the lateral edges of the thot·ax, and are always filiform and simply senated. The joints of the tarsi are always entire, without prolongations, and in the form of a palette underneath. The thorax is convex or arched, at least on the sides, and dilates at the posterior angles in the manner of a lobe, pointed or triangular. These Insects approach the Buprestides. |