| OCR Text |
Show 38 INSECTA. side, a character also observed in the Cercopis spumaria, while in the Cicadre there are four, two on each side. lu the Membracis cornutus the duodenal ear-like sac is replaced by a large pouch, but also attached to the esophagus by a suspensory filament, a character exclusively peculiar to these Insects. Some-Cantatrices-have antennre composed of six joints, and three simple eyes(l ). They embrace the division of the Manniferre ofLinnreus, the genus Tettigonia of Fabricius, and form that of our Cicadre proper. CICADA, Oliv.-Tettigonia, Fab. These Insects, of which the elytra are almost always transparent and veined, differ from the following ones, not only in the compo· sition of their antennre and the number of the ocelli, but in the absence of the faculty of leaping, and in the music of the males; which, in the heat of summer, the epoch of their appearance, pt·oduce that loud anrl monotonous sound which has induced authors to 'designate them by the name of Cantatl·ices or Singers. The organs by which it is effected are situated on each side of the base of the abdomen; they are internal and each one is covered by a cartilaginous plate, which closes like a shutter(2). The cavity which (1) The mesothorax, viewed from above, is much more spacious than the pro· thorax, and is narrowed towards the extremity, which forms a sort of scutellum. We observe nearly the same disposition of parts in Fnlgora, and other genera which are derived from it. The mesothorax has frequently the form of a reversed triangle, and the prothorax is generally very short and transversal. ln the fol· lowing Cicadaria:, such as the Membraces, Cicadella:, &c., it is, on the contrary, longer than the other thoracic segments, greatly developed in one direction or another, and tl1e mesothorax is only visible in the form of an ordinary and trian· gular scutellum. In all this family, the metathorax is very short and concealed. Considered in its relation to other Insects, the head of the Cicadaria:, viewed an· teriorly, ?resents a triangular space immediately above the labrum, corresponding to the ~p1stoma or clypeus; then, still higher up, another space, ft·equently inflated an~ stmtted, termed by Fabricius the frons, but which is analogous to the face or mterval between the eyes; above this comes the frons and then the vertex. (2) ~his piece .is merely an inferior appendage. of the ~eta thorax. The tymbal <Occup!l.ng a parttcular cavity, sometimes exposed above, sometimes cove1·ed and o~tly vtstble beneath, is a lateral prolongation of a skin which forms the anterior diapht:agm. of the two inferior cavities of the first segment of the nbdomen. The oppos~te dtaphra.g~, or the posterior of these cavities, constitutes the piece called the mirror, or m1rou·. It appears, that, like the othe1· diaphragm, it is formed at the ex~nse of the tral:heal membranes. HEMlPTEIL<\.. 39 encloses this apparatus is divided into two cells by a squamou::; and triangular septum. When viewed from the side of the abdomen, each cell presents anteriorly a white and plaited membrane, and lower down, in the bottom, a tight, thin, transparent membrane, which Reaumur terms le miroi1'. If this part of the body be opened above, another plaited membrane is seen on each side, which is moved by an extremely powerful muscle composed of numerous, straight, and parallel fibres, and arising from the squamous septum. This membrane is the tymbal. The muscles, by rapidly contracting and relaxing, act on the tymbals, alternately tightening and restoring them to their original state. Such is the origin of these sounds, which can even be produced after the death of the Insect, by jerking the muscle. The Cicadre live on trees or shrubs, of which they suck the juices. The female, by means of an ovipositor enclosed in a bilaminated semitubular sheath, and composed of three narrow, elongated, squamous pieces, two of which terminate in the form of a file, pierces the dead twigs to the medulla, in which she deposits her eggs. As the numbet· of the latter is considerable, she makes several holes, indicated externally by as many elevations. The young larvre however leave their asylum to penetrate into the earth, where they grow and experience their metamorphosis. Their anterior legs are short, have very stout thighs armed with teeth, and are adapted for digging. The Greeks ate the pupre, which they called Tettigometra, and even the perfect Insect. Previous to coition they preferred the males, and when it had taken place the females were most sought for, as their abdomen is then filled with eggs. The 0. orni, by wounding the tree from which its specific name is derived, produces that peculiar honey-like and purgative juice called manna. 0. orni, L. Rces., Insect. II, Locust. xxv, 1, 2; xxvi, 3, 5, About an inch long; ydlowish; pale beneath, the same colour mixed with black above; margin of the abdominal segments. russet; two rows of blackish points on the elytra, those nearest their inner margin the smallest. South of France, Italy, &c. C. plebeia, L.; Tettigonia fraxini, Fab.; Rces., lb. XXV, 4, 6, 7, 8. The largest species in France; black, with several spots on the first segment of the trunk; its posterior margin, the raised and arcuated portions of the scutellum, and several veins of the elytra, russet( l ). . (1). See Lat .. Gener. Crust. et Insect., IIJ, p. 154; Fab., Syst. Ryng., genus Tett, gonw, and Ohv., Encyc. Method., article Oigale, whet·e all the figures of Stoll, |
