Moths (Heterocera).—The antennæ of moths are bristly, gradually lessening from base to tip; when sitting the wings are turned down; and its flight is nocturnal. What the owl is among birds, the moth is among insects: it is a night-insect, carrying on its pursuits, and exercising all its activity amid the gloom of darkness. So numerous is the variety of moths, that there are upward of five hundred species.
The giant Owl-Moth of Brazil (Thysania agrippina) measures nearly a foot across from tip to tip of expanded wings, while the smallest are hardly visible to unaided eyes. The larvæ or caterpillars feed mostly on living plants, and in this connection are very familiar; others of these ravaging forms ruin clothes, furs, and the like. Almost the only directly useful form is the silk-moth.
Silkworm Moth. See under [Domesticated Animals].
STRAIGHT-WINGED INSECTS (Orthoptera)
The fore wings are either parchment-like or membraneous; the hind wings always membraneous. The wings cover the body horizontally, and do not meet in a straight line or ridge, as they do in the beetles. This order of insects undergoes only a partial metamorphosis, being produced from eggs in a wingless condition. The Cicadas, however, are an exception, [237] as they live in the ground frequently for years in the larva state. In this order are included the locust, cricket, grasshopper, cockroach, scale insect, plant-lice, and many kinds of bugs.
Crickets (Gryllus) are akin to grasshoppers. They have long feelers, a rasping organ on the wing-covers of the males, wings closely folded lengthwise, but often along with the wing-covers degenerate, great powers of leaping, and a retiring, more or less subterranean habit of life. Many of the species are wingless, and it is the males only which make a chirping sound. They are widely distributed, and all are herbivorous. The field cricket, house cricket and the common mole-cricket, are well-known representatives of the family.
Earwigs (Forficula) have two pairs of wings, very dissimilar, the anterior pair being short and horny, the posterior pair folded longitudinally and transversely; the mouth parts are well developed and suited for biting; the antennae are thread-like; there is no true metamorphosis in the life-history. The common earwig is best known for the pincer-like organ at the end of the abdomen.
Earwigs avoid the light, and do most of their work in the dark. They feed, as gardeners well know, on petals and other parts of flowers, on fruit, seeds and leaves, nor is animal debris refused. They are usually and readily caught in artificial shelters provided for their destruction.
The eggs of the common species are laid in spring, fifteen to twenty, in some convenient cavity. These are carefully watched, and even after the birth of the young earwigs, the mother still tends them as a hen does her chicks.
Grasshopper, a name given to numerous insects forming the locust family. They usually live among vegetation, in woods and thickets or in the open field. Most of them feed on flies and caterpillars, in catching which they use their powerful fore-legs, but many affect plants, and some combine both diets.