Another group includes a very large number of beetles of very varying character and appearance. Among these are the Oil-beetles, so called from their habit of exuding small drops of an oily liquid from the joints of their limbs when handled. The eggs are laid in batches of several thousand in holes in the ground, and the little long-legged grubs, on emerging, clamber up the stems of flowers, and hide themselves among the petals to await the coming of a bee. When one of the latter appears, two or three of the grubs cling to its hairy body, and are carried back to the nest, in which they live as parasites. One of these beetles may be seen commonly upon grassy banks in early spring.
Allied to these insects is the Blister-beetle, or Spanish Fly, so well known from its use in medicine. It is a very handsome species, of a bright golden-green colour, occasionally found in Great Britain on the foliage of ash-trees. In many parts of Southern Europe it is extremely abundant.
The beetles belonging to the large and important group of Weevils are characterised, as a rule, by the fact that the head is prolonged into a more or less long and slender snout, or "rostrum," at the end of which the jaws are situated. The number of species already known is above 20,000.
Photo by L. H. Joutel] [New York.
HARLEQUIN BEETLE.
Notice the enormous length of the front legs.
One of the largest and most famous of these insects is the Diamond-beetle of Brazil, the scales from whose wing-cases are so frequently mounted as microscopic objects. When viewed through a good instrument under a powerful light, the beauty of these scales is simply indescribable. All that one can say of them is that they seem to be composed of diamonds, rubies, topazes, and emeralds massed together in rich profusion, while diamonds are transformed into rubies, rubies into topazes, and topazes into emeralds at every change of light.
The Osier-weevil, a black-and-white species about three-eighths of an inch long, is found on osiers in Great Britain, the grub boring galleries in the stems, and often causing considerable damage. The well-known Corn-weevil is still more destructive in granaries, the walls of which are often completely blackened by its crawling multitudes. The grub lives inside the grain, eating out the whole of the interior, and a single pair of the weevils are said to be capable of producing a family of more than 6,000 individuals in the course of a single season. The Rice-weevil is equally destructive to rice, and may be recognised by the two red spots on each wing-case.
The famous "Gru-gru" of the West Indies, which is regarded as so great a dainty both by the negroes and by many of the white colonists, is the grub of the Palm-weevil. It lives in the stems of palm-trees, and also in those of sugar-canes, causing a great deal of mischief by its burrowings. When fully fed, it constructs a cocoon by tearing off strips of bark and weaving them neatly together. The Sugar-weevil is still more troublesome, feeding upon the juice of the sugar-cane, and affecting the entire plant in such a manner that sugar can no longer be manufactured from it.