Page:Encyclopædia Britannica, Ninth Edition, v. 6.djvu/158

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.
ABC—XYZ

132 COLEOPTERA labrum and strong mandibles suited for feeding on leaves. The club of the antennae consists of a variable number of plates, those in the male being considerably elongated and resembling a folded fan (Plate VII. fig. 23). The common Cockchafer (Melolontha vulgaris) is of a pitchy black colour clothed with a white pubescence or layer of minute scales. It is one of the commonest and most destructive of beetles, feeding in the perfect state on the leaves of the oak, beech, poplar, and elm, and sometimes appearing in such numbers as to utterly destroy the foliage over large districts; thus in the year 1688 they are said to have covered the hedges and trees in a district of Galway in such infinite numbers as to have hung in clusters like bees when they swarm. When on the wing they almost dark ened the light of day, and when feeding the noise of their jaws might have been mistaken for the sawing of timber. In a short time the foliage of the trees for miles round was so totally consumed that at midsummer the country wore the aspect of leafless winter. Destructive as they are in the perfect state they are still more injurious as larvae. The female buries herself beneath the surface of the ground and there deposits about 40 eggs. The larvae produced from these feed on the roots of grass and grain, thus "under mining," according to Kirby and Spence, " the richest meadows, and so loosening the turf that it will roll up as if cut with a turfing spade." These grubs continue their ravages for three years before undergoing metamorphosis, and thus do incalculable damage to the agriculturist. They are believed to have spread with the progress of agri culture, for it is only on soil rendered light and porous by tillage that they thrive. Enormous numbers of the grub are consumed by birds of the crow tribe, and it is princi pally in search of these that rooks so industriously follow the plough in England and France. The species is rare in Scotland. "Spinning" the cockchafer is a favourite but barbarous sport, practised by the boys of most countries in which this beetle commonly occurs, and seems to be at least as ancient as the time of Aristophanes, who refers to it in his Clouds as practised by the youth of Greece. Rose Beetles, Cetoniidce (Plate VIII. fig. 7), a beautiful tribe of insects, are distinguished from other Lamellicorn Beetles by the membranaceous character of their mandibles and maxillae. The Rose-Chafer (Cetonia aurata) is common in the south of England, where it feeds on the juices and petals of the rose, honeysuckle, and privet. It is about an inch long, of a brilliant-golden green above with coppery reflections beneath, and with whitish markings on the elytra. Its eggs are deposited among decayed wood, but certain species make use for this purpose of the nests of ants. The Goliath Beetles (Plate VIII. fig. 11) of tropical Africa are the largest of known Coleoptera, and their- larvae form enormous cocoons of mud in which they under go metamorphosis. One of these, Goliathus cacicus, is eaid to be roasted and eaten by the natives. VIII. Serricornes form a group of beetles chiefly distin guished from the others by their elongate filiform antennae of equal thickness throughout, or tapering towards the extremity, but generally serrated or pectinated. They are subdivided into the Sternoxi, characterized by the solid con sistence of their bodies, and by having the middle portion of the thorax elongated and advanced as far as beneath the mouth, and usually marked by a groove on each side, in which the short antennae are lodged, while the opposite extremity is prolonged into a point which is received into a cavity on the hinder part of the breast ; and the Mala codermata, characterized by their bodies being generally, in whole or in part, of a soft or flexible texture, and by the absence of the prolongation just referred to. The titernoxi include the Metallic Beetles, Buprestidce (Plate VII. figs. 18, 19) the most gorgeous of the Coleopterous families. " Nothing can exceed," says Westwood, " the splendour of colour in many of the species, being decorated with the most brilliant metallic tints ; some have a general coppery hue, whilst some present the beautiful contrast of fine yellow spots and marks upon a highly polished blue or green ground, and others exhibit the appearance of burnished gold or of rubies, inlaid on emerald or ebony." The elytra of the Metallic Beetles are those usually employed in the embroidery of ladies dresses and for other purposes of personal ornament. They are most plentiful in the thick forests of tropical countries, and seem partial to the various species of fir-trees. They pass their larval- stage in the heart of timber, and there is an instance recorded of the escape of Buprestis splendens from the wood of a desk which had stood in one of the Guildhall offices for over twenty years. Springing Beetles, Elatcridcn (Plate VII. fig. 30), are narrower and more elongate than the former, and their legs are so short that when they fall on their backs they are as unable to right themselves as a capsized turtle, but by bending the head and thorax back wards, and making use of the prolongation already described, they are enabled to spring to a height fully ten times their own length, and this operation they repeat until they fall on their feet. The noise which accompanies the springing process has earned for thein the name of Click Beetles. Some species of Elateridce are luminous in the dark, and are known as Fireflies. A South American form diffuses during the night from its thoracic spots a strong and beautiful light sufficient to enable a person to read ordinary type, particularly if several are placed together in a glass vessel. By means of this natural illumination the women of the country can pursue their ordinary work, and ladies use this fire-fly as an ornament, placing it among their tresses during their evening pro menades. The larva of Elater lineatus is known as the Wire-worm, a grub which often does great damage to the turnip crop. The Malacodermata include the Glow worms, Lampyridce (Plate VII. fig. 1), of which the best known is the common Glow-worm (Lampyris noctihica) (Plate VII. figs. 8, 9, 16), found in meadows and under hedges in England, but rare in Scotland. The male of this beetle has large wings and elytra, and flies swiftly, but the female is wingless and is a sluggish nocturnal creature ; the latter, however, emits a beautiful phosphorescent light, by means of which the male, who is generally concealed by day in the trunks of trees, is directed to his mate. In the perfect insect the luminous matter chiefly occupies the under part of the three last segments of the abdomen, which differ from the rest in colour, being usually of a yellow hue, and the luminous property is apparently under the control of the Glow-worm, for when approached it may frequently be observed to diminish or extinguish its ] ight. In form the larvae somewhat resemble the female, and possess in common with the pupae and eggs a slight degree of luminosity. The larvae are predaceous, attacking and devouring the smaller snails and slugs, b,ut in the perfect state they become entirely herbivorous, only eating the tender leaves of plants. Many of the Malacodermata are wood-borers ; these include the Death-watch Beetles (Anobium), which as larvae perforate chairs, tables, and other wood-work in such numbers as usually to render the wood completely rotten. During the pairing season they make a noise like the ticking of a watch, by striking with their jaws against the object on which they rest. This is intended as a mutual call of the sexes, but it has long been regarded by the ignorant as of evil omen, hence the name, and the import of Gay s words " The solemn death-vatch clicked the hour she died.

Another species, Lymerylon navale, abundant in the forests