LEPIDOPTERA

(Yunanca köken — orijinale bakınız.) The third order of insects in the system of Linnaeus, and the tenth in that of Latreille, who has given the following concise and comprehensive description of the characters common to the insects of this most interesting, useful, and beautiful group. The wings are four, covered on both sides with minute generally coloured scales, resembling farinaceous dust, which are removed by merely coming in contact with the finger. The oral apparatus consists principally of a proboscis, to which the name of antlia has been given, which is rolled spirally between two palpi, covered with scales or hairs. This forms the most important part of the mouth, and is the instrument with which these insects extract the nectar from flowers, their only aliment. It is composed of two tubular threads, representing the maxillae, each bearing, near its external base, a very small superior palp, in the form of a tubercle. The apparent (inferior) palpi, which form a sort of sheath to the proboscis, replace the labial palpi of the mandibulated insects: they are cylindrical or conical, usually turned up, composed of three joints, and inserted in a fixed labium, which completes that portion of the buccal cavity inferior to the proboscis. Two little and scarcely distmct, corneous, and more or le ciliated pieces, situated, one on each side, on the anterior and superior margin of the front of the head, near the eyes, soem to be vestiges of mandibles. Finally, we observe, and under an equally small proportion, the labrum or upper lip. The antennae vary, and are always multi-articulated. Two ocelli are observable in several species, but concealed between the scales. The three segments of which the thorax is usually composed are united in one single body: the first is very short, and the two others are blended together. The scutellum is triangular, but the apex is directed towards the head. The wings are simply veined, and vary in size, figure, and position; in several the inferior ones are plaited longitudinally near the inner 654 LEPIDOPUS. margin. At the base of each of the superior wings fs a kind of epaulette, prolonged posteriorly, which corresponds to the piece called tegula in the HjTnenoptera. The abdomen, composed of from six to seven annuli, is attached to the thorax by a very small portion of its diameter, and presents neither sting nor ovipositor. In several females, however, as in Co ns, the last rings become narrowed and extended, to form an oviduct resembling a pointed and retractile tail. The tarsi always have five joints. There are never more than two kinds of individuals, males and females. The females usually deposit their ova, frequently very numerous, on the vegetable surfaces which are to nourish their larvae, and soon after perish. The larvae of Lepidopterous insects are well known by the name of caterpillars. They have six squamous or hooked feet, which correspond to the legs of the perfect insect, and from four to ten additional mgnbranous ones, or pro pedes; the two last of which are situated at the posterior extremity of the body. Those caterpillars which have but ten or twelve io all have been called, from their mode of progre ion, geometrcs. Several of these geometers, when at rest, remain fixed to the branches of plants by the hind feet alone, whence in the form, colour, and directions of their body, they resemble a tv/ig. They can support themselves in this position for a long time without exhibiting the slightest symptom of life. So fatiguing an attitude must require prodigious muscular force •, and, in fact, Lyonnet counted 4041 musclet in the caterpillar of the Co vs ligniperda. The body of these larvae is generally elongated, almost cylindrical, soft, variously coloured;" sometimes naked, and sometimes covered with hairs, tubercles, and spines. It is composed of twelve segments or annuli, exclusive of the head, with nine stigmata on each side. Their head is invested with a corneous or squamous dermis, and presents on each side six shining granules, which appear to be ocelli; and it is furnished with two very short and conical antennae, and a mouth composed of strong mandibles, two maxillae, a labrum. and four small palpi. The silk which they use is elaborated in two long and tortuous internal ve els, of which the attenuated superior extremities terminate in the lip. A tubular and conical mamilla forms the spinnaret through which the threads are spun. Most caterpillars feed on the leaves of plants; some gnaw their flowers, roots, buds, and seeds; others attack the ligneous or hardest part of trees, softening it by means of a fluid which they disgorge. Certain species attack our woollens and furs, thereby doing us much injury; even our leather, bacon, wax, and lard, are not spared by them. Several confine themselves exclusively to a single article of diet; others are le delicate, and devour all sorts of organized matters. Some of them form societies, and frequently live under a silken tent, spun by them in common, which even shelters them in winter. Several construct sheaths for themselves, either fixed or portable; others make their abode in the parenchyma of leaves, where they form galleries. The greater number are diurnal: the others never i ue forth but at night. The severity of winter, so fatal to almost all insects, does not affect certain Phala;ncE, which only appear in that season. Caterpillars usually change their skin four times previously to pa ing into the state of a nymph or chrysalis. Most of them spin a cocoon in which they enclose themselves. A frequently reddish liquor, which Lepidopterous insects eject at the moment of their metamorphosis, softens or weakens the extremity of the cocoon, and facilitates their exit: one of these extremities, also, is generally thinner than the other, or presents a favourable i ue by the peculiar disposition of the fibres. Other caterpillars are contented with connecting leaves, particles of earth, or of the substances on which they have lived, and thus forming a rude cocoon. The nymphs of the diurnal Lepidoptera are ornamented with golden spots, whence the term chrysalis applied to them: they are naked, and fixed by the posterior extremity of the body. The nymphs of all the Lepidoptera are swathed, or resemble mummies. Those of several insects of this order, particularly ol the DiurruB, undergo their metamorphosis in a few days; they even frequently produce two generations in the course of the year. 'I'he caterpillars or chrysalides of others, however, remain during the winter in one of these states, and undergo their final transformation in the ensuing spring. The Lepidoptera i ue from their nyraphal envelop through a slit, which is eflected in the back of the thorax. [s. 667]