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Moths (Heterocera Under this name)

(Heterocera). Under this name are denoted such of the order Lepidoptera, or scale-winged insects, as are not included among the Butterflies (Rhopalocera). (See Insects for the characters that distinguish Lepidoptera from other insects.) Butterflies are a far more uniform group than Moths, and differ from them in having the antennae, or feelers, almost always clubbed at the tip, but elsewhere slender. Rhopalocera means club-horned. Their wings are usually folded back, when at rest, so as to display the lower surface, which often bears bright colours; and the body is usually slender. Moths, on the other hand, have the antennae sharp-pointed, with no club, but otherwise variable, being branched, slender, feathery, or of some other form. Heterocera means varied-horned. Some have the body slender, and the wings folded, as in Butterflies, in which case, the lower surface is seldom conspicuously coloured; but usually the body of the insect is heavy, without marked distinction between the middle body (thorax) and the hind body (abdomen); and the wings are usually folded flat on the back, the hind wings being so folded, lengthwise, as to lie entirely below the narrower forewings when at rest. In almost all, the two wings on each side are connected by a bristle, or a tuft of stiff hairs, that projects from the front edge of the hind wing, and plays in a kind of socket or ring on the fore-wing. It is more difficult to state any constant differences between the caterpillars of Butterflies and Moths than between the perfect insects, though it is usually possible for a practised entomologist to distinguish the groups even in this stage; and so also with the pupae.

Moths are of far greater practical importance than Butterflies, for the caterpillars of several species do very serious injury to fruit-trees, to potherbs, and to other cultivated plants. It is possible to ward off, or at least to lessen, the evil done by such species in some cases; but in others the insects are so well protected in the leaves, or others parts of plants, as to render remedial measures practically hopeless; and the affected parts, or the entire plants, must be destroyed to prevent extension of the injury. There is usually little difficulty in recognising the caterpillars of Lepidoptera, the only other group of insects in which somewhat similar larvae are found being the Sawflies, among the Hymenoptera. But, while they retain a strong general likeness, they yet vary exceedingly in many points, such as the number of prolegs, or fleshy legs, on the hinder rings of the body; the colour and markings; and the skin, in some smooth, in others warty, or covered with hairs, bristles, or long spines. Nor are they less varied in their habits and modes of life, though, with few exceptions, they feed on, or in, living plants. The larvae of a great majority of the Butterflies, and those of many Moths, live on the surface of the leaves, or other organs of their food-plants, exposed to full view. Frequently, such exposed larvae are brightly coloured; but, on experiment, it has often been found that they are distasteful to birds, because of unpleasant fluids thrown out by them, or of the hairs or spines on their bodies. The caterpillars of most Moths feed hidden from view in some way. The concealment is secured, by some, by hiding below the soil, or in crevices, during the day, and crawling out to feed only during night. Others roll up leaves, or spin two or more together, and feed in shelter of the cover so formed; while other combine to form large webs (see Hawthorn Caterpillars), in which they lie, and feed protected. Many others bore into the roots or stems of plants (see Leopard Moth), or between the surfaces of leaves (see Leaf Miners), and thus find food, as well as protection. A few others, chiefly small kinds, prefer dead and dried vegetable or animal products, such as corn, peas, woollen cloths, bees' combs, &c.; and these are frequently very trouble-some in houses.

The methods of remedying injuries caused by larvae of Moths, and of preventing future attacks, must depend largely on the habits of the insects, both in the perfect and the larval stages of development. They are mentioned under Insects (which see), and under special tribes or genera, noted below. Moths pass through a complete metamorphosis. The larvae seek out safe retreats in which to become pupae, or chrysalides. These retreats may be in crevices, or in the galleries made by them in the plants; or among dead leaves; or under the soil, in earthen cells, lined with silk. Less often they spin a silken cocoon, in some exposed situation, and trust to this covering for their protection. The pupae are defenceless, with the limbs all firmly bound down to the body by a hard shell or coating of chitine. The only power of motion they possess is that of wriggling some of the hinder rings of the body. In the pupa-case the Moth becomes fully developed; it then bursts the case, along the front half of the back, and crawls out, with the wings small and soft at first. But these organs at once begin to grow, and in an hour or two they reach their full size, and soon become firm, and fit for flight.

The females of various kinds of Moths (see Hybernia) never have the wings useful for flight; but in them the wings remain small, or may even be entirely absent. Moths form several well-marked tribes; though these grade into one another in such a way that it is difficult, at times, for a beginner to distinguish to which tribe certain individuals belong. The more reliable distinctive characters of the groups are noted below. Most kinds of Moths can be reared with comparative ease, from the larval state, in confinement; hence, the life-histories of these insects are far more thoroughly known than those of any other group. But it would be beyond the scope of this work to enter on the methods of rearing, capturing, and preparing Moths for permanent preservation, despite the interest of such pursuits.

Moths are divided into two great sections; the Macro lepidoptera (meaning large scale-winged insects), seldom under 1in. across the outspread wings, and often much larger; and the Microlepidoptera (or small scale-winged insects), seldom exceeding 1in. across the wings (except in Pyralidina), and often much smaller. In both sections there are numerous species that injure cultivated plants. Each section includes several tribes, which are generally more or less characterised by the habits of the larvae, as well as by peculiarities in the structure of the perfect insects. The following are the more important tribes and families: 1. Sphingina or the Hawk Moth tribe, including the true Hawk Moths, the Humming Bird Hawk Moths (see Macroglossa stellatarum), and the Clear-wing