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Show 296 INSECTA. des Sc. Nat., X, 248, 11-M. Leon Dufour has described the larva! of two species; the 0. cassidE£ and the 0. bicolor. That of the first species lives in the visceral cavity of the Cassida bicolor, and that of the second in the same situation in the Pentatoma grisea. Both of them feed exclusively on the epiploon or corps graisseux of their hosts. Their body is oblong, soft, whitish, perfectly glabrous, ru-gose and contractile. Its anterior extremity presents two mammillre, each furnished with two little cylindrical bodies terminated in the manner of a button umbilicated in the centre, and with as many strong, horny pieces, each provided exteriorly with one or two large hooks, which gives them the appearance of being forked, and their convex sides placed back to back. From the figure given by ·this naturalist, it would seem that there is one for each mammilla, and that they are internal. He considers them as mandibles, and the species of palpi, of which we have just spoken, the disk of which is perforated in the centre, as a sort of foot-pal pi, acting like a cup or organs of touch. The body of these larvre terminates by a sort of siphon, about one third as long as the body, of a more solid consistence and constant form that becomes gradually narrowed, and with the appearance of two hooks at the end. The posterior extremity of this siphon oc· cupying one of the metathoracic stigmata, and being in contact with the air, enables the larva to respire. Neither antennre nor eyes can be perceived. It. is in this same abode that the larva passes into the state of a pupa. The latter is ovoid, exhibits no trace of annuli, and presents at one ~xtremity four ( 0. cassidE£) or six ( 0. bicolor) tubercles. It leaves its domicil previously to attaining its perfect condition, sometimes while the Insect in which the larva resided is still living, and sometimes at the expense of its life. These larvre have two salivary vessels, four biliary vessels, and tubular trachere without a nacred aspect, or transverse strice, arranged in two prin· cipal trunks, and giving oft' numerous ramifying branches. These trunks appear to empty into a unique orifice at the base of the caudal siphon. The alimentary canal is about four times the length of the body, and presents a capillary esophagus, a crop resembling a turbinated bowl of a pipe, which insensibly degenerates into a tubular, doubled stomach, followed by a flexuous intestine, a slightly apparent rectum, and terminated by an oblong c;Ecum(l). (1) Idem., and the Ency<;.~ Method., article Ocyptere. DIPT.ERA. . In the following subgenus, or MELANOPHORA, Meig. 297 Which he suppresses and um. tes to Tach· th much shorter, their extt·emit h ma, e antennre are d . y, w en they are . r d ten Ing beyond half the I h f mc me ' scarcely ex- . engt o the face of th h d exterior of the two com lete cell . ~ ea . The most · much more prolonged p . s, which termmate the wing, is posteriorly than the oth d angle of its extremity is obtuse(!). er, an the internal The abdomen of the other Creo hil . and triangular· the WI. d . p ce is but shghtly elongated ' ngs o not v1brate. PHANrA, Meig. Where the posterior extremit f h . rowed and ~bent underneath. ~-~e \h~ abd.o~en lS elongated, oar-elongated and linear Th . Ird JOmt of the antennce is I · e wmgs, according to the fig f M . c osely resemble those f th . . ures o eigen, the same author the b~ e pre:edmg subgenus. According to ' a omen, as m the Lophosice and 0 presents but four apparent annuli(2)· I n t h e subgenus . cypterre, XYSTA, Meig. There .a r.e from five to six · The an t ennc. e .a re short d th · two last JOints nearly of ll ' an e1r sligh~ly arcuated, compre:~~q::d =~f:~~. The posterior tibire are theT hG1 s subgenu. s a ppears to us to constitute the transition from o d ymnosom J<e . to the Ph as.1 r e ' ancl a1 s o to approach the Trichi-po a. The equivocal nature of the character drawn from ~esen?e or ~bsen~e of hairs on the face of the head, employed t:e • b~e•gen,.u e~sliy perceived. Certain species of Trichiopoda ar~ am Iguous m th1s very respect(3). TAOHINA, Fab. Meig. Where the abdomen is not curved underneath at its posterior ex- (l) Lat., Gener., Crust. et Insect., IV, 3,6. (2) See Meigen. (3) Idem. VoL. IV.:-2 N |
