Winter Moths
A name given, because of the time of their appearance, to certain moths belonging to the group Geometrina (see Moths), which is characterised by the possession of a slender body, and wings large relatively to their size of body. Of the Winter Moths, however, the females are wingless, or, rather, possess mere vestiges of wings, utterly useless as organs of flight; the males are well provided with wings of considerable size. Most of the species are included in the genus Hybernia (which see); but the insect to which the name is peculiarly applied, and which is most widely destructive, is Cheimatobia brumata. In this species the spread of wings of the male may reach about 1 1/4in.; but it is usually under this size. Both sexes are greyish-brown, with several indistinct, darker, wavy lines or bands across the wings. The female is heavier in the body, and has extremely small front wings. The moths appear between the beginning of October and the end of December. The females must crawl up the trees to reach a suitable situation for laying eggs; or they may, at times, be carried from one place to another by the males. The eggs are usually laid in the crevices of the bark, and in other places fitted to give them protection. The larvae are bluish-green, with a narrow, dark stripe down the middle of the back, and three narrow, white stripes on each side. In some the ground-colour is smoky or dark brown. They live upon almost all kinds of trees and shrubs. At first, they eat into the buds in early spring; and, when the leaves begin to enlarge, the larvae spin two or more leaves together, and feed, protected between them, in safety. When full-fed, they lower themselves to the ground, burrow into it, and form earthen cocoons, in which they become pupae about the end of May or the beginning of June. Remedies. The larvae of C. brumata are so destructive that it is often most desirable to prevent or to check their ravages. Nothing can be done while the larvae are in the buds; but, when nearly full fed, and living between the leaves, they can be dislodged by beating and shaking the branches. The shock cause them to lower themselves by silken threads, or to fall to the ground. They can thus be collected in cloths spread below the plants, or crushed under foot. It is well to put a belt of some sticky substance on the base of the tree-trunks, to prevent the reascent of larvae. Digging the soil around the roots helps also to lessen the number of pupae, by exposing them to the quick eyes of birds, or to predacious insects. The most effectual remedies are those employed for the destruction of the females, and for the prevention of their ascent of the tree-trunks. This is effected readily, because of the useless nature of their wings, which compels them to creep up the trunk, unless at times carried on to the trees attached to the males. Whatever substance is used, it must remain soft and sticky for a day or two, must not injure the trunks, and must be renewed sufficiently often to keep the surface of the ring of bark sticky, say about each second day. Among the best of the compounds for catching female moths is the substance known as Davidson's Composition, or a mixture of tar and grease in equal proportions.