Orchestes
(Spring Weevils). The name given to a genus of Curculionidae (small beetles) that, at times, do great harm to Beech-trees and hedges, and, in a less degree, to Oaks, and to a few other trees. They are usually about 1/8in. long, but may vary from 1/10in. to 1/5in., and, in colour, are reddish, brown, or black. The body is nearly oval; the head is small, and the beak about as long as the thorax, and strongly bent downwards; the antennae are situated near the base of the beak, and are eleven-jointed and elbowed, with the club oblong-ovate. But the most ready means of recognising them is their power of leaping, which is given by the great size of the thighs of the last pair of legs. The enlarged thighs contain correspondingly powerful muscles, and the beetles, when touched, leap surprising distances.
Mode of Life. Those that survive the winter eat their way into buds, and the females lay their eggs alongside the midribs, on the lower surface of the leaves. The larvae burrow into the leaves, and there form large galleries or patches between the surfaces, and in these change to pupae, from which the beetles soon emerge. A severe attack by these insects on any kind of tree or shrub causes the leaves to become prematurely withered, or even useless, and considerably injures the health of the plants.
Remedies. In the mornings, shake the beetles off the plants, over a tarred vessel, from which they cannot escape, and pick off and destroy the leaves that show mines of the larvae. Of course, both methods are applicable only to small trees. Very little can be done to limit the injury to forest-trees; but of these we are not treating here. The most hurtful insects in this genus are: O. Fagi--a small species (1/10in. long), black, with a faintly reddish, less often greenish, thin coating of short hairs, limbs paler, thighs one-toothed--often very abundant in June and July on Beeches; and O. Quercus--which is larger (1/8in. to 1/5in. long), of a dull brick-red colour, slightly hairy, eyes black, wing-cases with a large triangular ashy patch over their place of meeting at the base, thighs of front legs each one-toothed, of hinder pair each with a double row of six or seven spines--frequent on Oaks. Others occur on Alder, Hazel, Elm, &c., but do not call for a longer notice.