Beetle - Students | Britannica Kids | Homework Help

There are more species of beetles than of any other kind of insect. They constitute the largest order of insects—Coleoptera—which includes more than a third of a million recognized species. In fact, the beetle order is the largest order in the entire animal kingdom. About a quarter of all known species of animals in the world are beetles. These insects are characterized by a pair of special hardened forewings that serve as a protective covering for a second pair of wings used for flying.

Beetles are found throughout all continents except Antarctica, in all but the most extreme environments. Although most species live on land, many—such as the whirligig, water scavenger, and true water beetles—have become adapted to aquatic environments. Some beetles are only about 0.01 inch (0.025 centimeter) long, whereas some tropical rhinoceros beetles and goliath beetles may reach lengths of 4 to nearly 8 inches (10 to 20 centimeters).

Beetles display a remarkable array of colors, forms, and habits. Some are plain black or have brownish patterns that help to camouflage the insects against certain types of wood or soil. Some beetles are brilliant orange, red, or yellow; others are iridescent green or blue or have a metallic sheen. The antennae of some beetles are large and ornate. Some stag beetles have enlarged, hooked mandibles, or lower jaws, that are almost as long as the beetle itself. Male rhinoceros beetles have huge horns projecting over their heads. The shapes of beetles’ bodies vary from round to elongate. Some are flattened; others are domed or cylindrical.

Some beetles are of great significance to humans. Among the members of the family of beetles known as weevils, or snout beetles, are notorious agricultural pests that can destroy growing crops and stored grains. Some beetle species feed on plant materials such as wood, paper, and fabrics. The larvae of some dermestid beetles are destructive pests of clothing and carpets and even of plant and animal specimens in museums.

Certain beetles are valuable because they prey on destructive insect pests. Ladybugs, or ladybird beetles, for example, eat untold numbers of aphids each year and so protect a wide variety of flowers and vegetables. Many other beetles play more subtle but equally important roles in various ecosystems. Dung beetles, or tumblebugs, consume vast quantities of dung in livestock areas. Carrion beetles are scavengers whose larvae feed on dead animals. Many beetles pollinate flowers.