Colorado Beetle (Chrysomela) is a North American beetle which commits fearful ravages among potatoes. It is an oval insect, of an orange color, with black spots and lines. The antennæ are club-shaped. The larvæ and adults live on the potato-plant, and have sometimes quite destroyed the crop in certain parts of the United States. They pass the winter underground, and emerge from their hiding-places in the beginning of May. The female lays many hundreds of eggs in groups of twelve to twenty on the under side of potato leaves. The larvæ, which emerge in about a week, are reddish and afterwards orange. They grow up quickly and produce a second generation, which may again produce a third in the same summer. Their rate of multiplication is therefore very rapid. The surest remedy in case of attack is said to be a preparation of arsenic known as “Paris Green.”
Scarabæus (Ateuchus sacer), one of the dung-beetles well known for the zeal with which they unite in rolling balls of dung to their holes. The dung serves as food, and a beetle having secured a ball seems to gnaw at it continuously—sometimes for a fortnight—until the supply is exhausted. Sometimes an egg is laid in the ball, and the parents unite in rolling this to a place of safety. There are numerous American species.
By the Egyptians the scarabæus was venerated during its life, and often embalmed after death. Entomologists have recognized four distinct species sculptured on the Egyptian monuments, and gems of various kinds of stones were often fashioned in their image.
Stag-beetles (Lucanus) are nearly allied to the scarabees. The males are remarkable for the large size of their mandibles, the branching of which has suggested stags’ antlers. The common stag-beetle is a large formidable-looking insect, the males being fully two inches long, and able to give a sharp bite with their strong mandibles. It flies about in the evening in the middle of summer, chiefly frequenting oak-woods.
These insects habitually are well known to fight for possession of a coveted mate. For this purpose the mandibles of the male are enormously developed, and frequently there occurs a most amusing tussle, one beetle striving to gain the side of his lady-love, the other balking him. Eventually one suitor admits defeat by turning tail and making off, while the victor marches in triumph to the fair cause of all the trouble, and begins to court her.
The huge Hercules Beetle of South America has been seen to carry off his mate bodily in this way. Other tropical beetles have specially developed forelegs for grasping their spouse, should she prove coy and attempt playfully to run away.
Water-beetles (Ditiscus marginalis) are carnivorous types which have become adapted to life in freshwater, although the adults have not lost the power of flight. In our native great water-beetle the large hind legs are fringed with bristles, and serve as oars, while air can be stored under the wing-covers. There is only a partial metamorphosis.
Weevil is a popular name for a large number of beetles, marked by a beak or proboscis, generally used by both sexes as a boring organ. Among ten thousand described species are the American species Trichobaris trinotata, a small black weevil which destroys potatoes, and Conotrachelus nenuphar, which lays its eggs in various fruits and is a great pest, and the Entimus imperialis, the diamond-beetle with very brilliant scales.
Wire-worms are the grubs of skip-jack or click beetles, perhaps the most injurious of farm pests. They are called wire-worms “from their likeness in toughness and shape to a piece of wire;” they are yellowish in color, from one-quarter to one-half an inch in length, with three pairs of legs, and a suctorial appendage below the tail. The eggs are laid near the roots of plants, in the ground or in the axils of leaves; the grub remains for several years (three to five) as such, burrowing in the ground during the frost of winter, but at other times hardly ceasing from voracious attacks on the roots and underground stems of all sorts of crops. Dressing of lime, salt, nitrate of soda, etc., have been recommended as remedies.