MUSK-BEETLE.
The odour of this beetle may often be detected at a distance of twenty or thirty yards.
Another very large group of beetles is represented by the Cellar-beetle, which is generally very common in old houses. This insect must not be confused with the so-called "Black-beetle," from which it may easily be distinguished by its deep black colour, its very much shorter feelers, and the curious point into which the end of its body is produced. It hides away in dark corners by day, and crawls slowly about by night. Related to it is the Meal-worm, so much in request for the food of cage-birds, which is usually very plentiful in granaries.
Very different, in appearance, yet belonging to the same group, is the handsome Cardinal Beetle, a bright scarlet insect which is not uncommon in summer. It may sometimes be found lurking behind pieces of loose bark, and is also fond of resting upon the flowers of umbelliferous plants in the hot sunshine. A second species, which is not nearly so plentiful, may be distinguished by the fact that the head is entirely black.
Still more curious is the Rhipiphorus Beetle, which is parasitic within the nests of wasps. Where the egg is laid, or how the grub first finds its way into the nest, no one has yet succeeded in discovering; but having made its entry, the insect proceeds to burrow into the body of a wasp-grub, and lives within it for several days, feeding upon its flesh meanwhile. After increasing considerably in size, it creeps out of the carcase of its victim and changes its skin, after which it resumes its interrupted meal, and continues to feed until the last vestige of the wasp-grub has been devoured. It then changes to a chrysalis in the cell, and the perfect insect appears a few days later. Oddly enough, the wasps appear to take no notice of its presence, and never attempt to molest it. The two sexes of this beetle are quite unlike one another, the male having the wing-cases yellow and the feelers heavily plumed, while the female is black, with the feelers only slightly toothed.
Most singular of all the insects belonging to this order, however, is the strange little Stalk-eyed Beetle, which spends the greater part of its life half buried in the body of a bee. In this insect the feelers are branched, somewhat like the antennules, or lesser feelers, of a lobster, and the eyes, which are comparatively few in number, are set at the ends of short foot-stalks. The male has very narrow wing-cases, but extremely large wings, which have a milky appearance during flight that can hardly be mistaken. The female has no wings at all, and in general aspect is nothing more than a grub. In early spring a great number of solitary bees are infested by this extraordinary parasite, which burrows into their bodies under cover of the projecting edges of the segments, and there remains feeding upon their internal juices for several weeks, with only just the tip of its tail protruding. When fully fed, it emerges from the body of its involuntary host, leaving a large round hole behind it, which frequently closes up and heals. In any case, strange to say, the ravages of the parasite appear to have but little effect upon the health of the bee.
STRAIGHT-WINGED INSECTS, OR EARWIGS, COCKROACHES, SOOTHSAYERS, STICK-INSECTS, CRICKETS, GRASSHOPPERS, AND LOCUSTS.
BY W. F. KIRBY, F.L.S.
The insects of this order are less numerous in species than those of any other but the next, and are easily recognised. The fore wings are usually of a leathery consistency, and the hind wings are folded beneath them like a fan in the more typical families, though in the Earwigs and Cockroaches a somewhat different arrangement prevails. In the Earwigs, indeed, the wings are doubled back at the ends, and in the Cockroaches the wing-cases, or "tegmina," as they are technically called, overlap. As a rule these insects feed entirely on vegetable substances. The "Soothsayers" form an exception, being carnivorous, though they are not parasitic, like the Ichneumon-flies, but feed on fresh food; and several species of Earwigs, Cockroaches, and Crickets, especially those which are semi-domesticated, are omnivorous, and will eat animal as well as vegetable food. These insects have an imperfect metamorphosis—that is, there is no inactive pupa-state; but, the young, on emerging from the egg, already possess a recognisable resemblance to their full-grown parents, and their metamorphosis consists of a series of moults, before the last of which rudimentary wings appear in those species which ultimately acquire these appendages. A considerable number of species never have wings, a circumstance which frequently renders it difficult to determine whether a specimen is fully developed. The antennæ are usually long, and the joints distinctly separated, but are very rarely feathered. At the other end of the body we often find two long jointed organs, called "cerci." The jaws are always furnished with strong mandibles. Many Grasshoppers and Locusts have a curious arrangement on the shank of the front leg, consisting either of a round or an oval cavity on each side, closed by a membrane, or of two long parallel slits in front. These are considered to be organs of hearing. The largest known insects belong to this order; the proportion of large or moderate-sized species is considerable; and the smallest are probably considerably larger than the smallest members of any other group. They are not numerous in temperate climates; there are only about fifty British species, and most of the larger of these are either naturalised species, or merely casual visitors from abroad.
