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Show 494 INSECTA. The third general section of the Coleoptera, that of the TETRAMERA, consists exclusively of those in which all the tarsi are quadriarticulated(l ). All these Insects live on vegetable matters. The feet of their larvre are usually very short, and they are even wanting or are replaced by mammillre in a great num her. The perfect Insect is found on the flowers or leaves of }llants. I will divide this section into seven families. The larvro of the first four or five most commonly live concealed in the in· terior of plants, and are generally destitute of feet, or have but very small ones ; many attack the hard or ligneous por· tions of their domicil. These Coleoptera are the largest of the section. FAMILY I. RHYNCHOPHORA(2). This family is distinguished by the entire prolongation of the head, which forms a sort of snout or proboscis. (1) lf the first joint of a Pentamerous tarsus be very short, and the second ac. quire in length what the other has lost, the tarsus becomes Tetramerous. Hence, in this respect, some Insects become equivocal. . {2) Since the publication of the fit·st edition of this work, Messrs Germar and Schrenherr have especially devoted their attention to this family, and created~ great number of new genera, amounting (in the work published by the latter on these Insects in 1826) to one hundred and ninety-four, exclusive of subgenera. To describe them is so much the more at variance with our plan, as it would com· pel us to enter into a multitude of very minute details. On this subject, therefore, we refer the reader to our article Rhynchophm·e in the Dictionnaire Classique d'llistoire Naturelle, where we have given a general view of these sections, but in a new, and, as we think, a more natural order. The following is a brief sketch of the same. The Rhynchophora, called by Sclw;:nherr Cucurlionites, are divided, according as the antennre are straight or geniculate, into two great sections, the Recticornes or Orthocera, and the Fracticornes or Gonatocer~. The anatomical ob· eervations of M. Leon Dufour seem to strengthen this distinction. The latter are furnished with salivat·y vessels, while in the former they are wanting. These form four t1·ibes, the Brucltele..~, th~ .llnt!tribides, the .llttelabides, and the Brentides. The labrnm and pal pi are very visible in the two first; these pal pi are filiform or larger at the extremity; they are ve1·y small and conical in the two other tribes, as in 311 tlw following Hhynchophol'a. The Fracticot·nes form a fifth tribe, that of the Cu COLEOPTEU.A. 495 The abdomen is bulky in most of them, the antennre geniculate, and frequently clavate. The penultimate joint of th tarsi is almost always bilobate. The posterior thighs are den~ tated in several. The I.arvre have an ?blong ~ody, and resemble a small, very soft, wh1te worm; their head IS squamous, and they are destitute of feet, or in lieu of them there are merely small mammillre. They ~n&W _various p~rts o~ plants. SeveraJ live exclusively in the mter10r of their frmt or seeds, and frequently do us much injury. Their chrysalides are enclosed in a shelL Many of the Rhynchophora, when very abundant within certain limits, are even very noxi~us in th~ir p'erfect state. They tap the buds or leaves of various cultivated ·vegetables, useful or necessary to man, and feed on their parenchyma. In some the labrum is apparent, the anterior elongation of their head sho1·t, broad, depressed, and in the form of a snout; the palpi are very visible and filifo1·m, or larger at the extremity. They compose the genus curlionites. They are divided into the Brevirostres and Longirostres, thereby in. dicating the insertion of their antennre. In the former, these organs, at their origin, are even with the base of the mandibles, and behind or nearer the head in the other. The genera of the Brevirostres are arranged in three sub-tribes, viz. the Pachyrhyncides, Brachycerides, and Liparides, which correspond to the genera Curculio, Brac!Lycerus, and Liparus of Olivier; the last also comprises some of his Lixi. The relative size and form of the mentum, the mandibles, the presence or absence of wings, the direction of the lateral sulci of the proboscis, or rather of the proboscis-snout (museau-trompc), where the first joint of the antennre is partly lodged, the length of that joint, the proportions and forms of the thomx, and other very secondary considerations, furnish the characters of these various groups. The Cucurlionites Longirostres are divided into two principal sections from their habits, and the composition of their antenna:. In the Phyllophagi, they consist of ten joints at least, and the three last, at least, form the club which terminates them. Those of the Spermatopltagi present at most but nine joints, of which the last, or two last at most, constitute the club. The legs of the Phyllo· ,Phagi are sometimes contiguous at their origin, and sometimes remote. Those in which they touch are divided into four tribes: the Lixides (Lixus, Fab.), the Rhynchtcnides (Rhynchreus, Oliv. ), Cionides (Cionus, Clairv. ), and the Ord,estidu (Orchcstes, Illig.). The Spermatophagi are divided into three principal sections, or sub-tribes: the Calandrreides (Calandra, Clairv., Fab.), the Cossomides (Cossomus, Clairv. ), and the lJryopthoride3 (Dryoptborus, Schrenh.-Dulbifer, Dej.). · These latter lead to the Hylesimi, Fab., and other Xylophagi. · |