Beetles are a group of insects that form the order Coleoptera, in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal life-forms; new species are discovered frequently. The largest of all families, the Curculionidae (weevils) with some 70,000 member species, belongs to this order. Found in almost every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae eat aphids, scale insects, thrips, and other plant-sucking insects that damage crops.
The family Scarabaeidae as currently defined consists of over 30,000 species of beetles worldwide, often called scarabs or scarab beetles. The classification of this family has undergone significant change in recent years. Several subfamilies have been elevated to family rank, and some reduced to lower ranks. The subfamilies listed in this article are in accordance with those in Bouchard (2011).
The telephone-pole beetle is a beetle native to the eastern United States, and the only living representative of the otherwise extinct family Micromalthidae. Classification of M. debilis was historically controversial and unsettled. The species, first reported by John Lawrence LeConte in 1878, was long considered one of the Polyphaga, and placed in the Lymexylidae or Telegeusidae, or as a family within the Cantharoidea. However, characteristics of larvae, wings, and male genitalia show that it is in the suborder Archostemata, where it has been placed since 1999.
The Hydroscaphidae are a small family of water beetles known commonly as skiff beetles. As of 2010, there are 23 species in the family. Several are recently described.
Rhysodidae is a family of beetles, consisting of more than 350 species in about 20 genera.
The soldier beetles (Cantharidae) are relatively soft-bodied, straight-sided beetles. They are cosmopolitan in distribution. One of the first described species has a color pattern reminiscent of the red coats of early British soldiers, hence the common name. They are also known commonly as leatherwings because of their soft elytra.
The longhorn beetles are a cosmopolitan family of beetles, typically characterized by extremely long antennae, which are often as long as or longer than the beetle's body. In various members of the family, however, the antennae are quite short and such species can be difficult to distinguish from related beetle families such as the Chrysomelidae. The family is large, with over 26,000 species described, slightly more than half from the Eastern Hemisphere. Several are serious pests. The larvae, called roundheaded borers, bore into wood, where they can cause extensive damage to either living trees or untreated lumber. A number of species mimic ants, bees, and wasps, though a majority of species are cryptically colored. The rare titan beetle from northeastern South America is often considered the largest insect, with a maximum known body length of just over 16.7 cm (6.6 in). The scientific name of this beetle family goes back to a figure from Greek mythology: after an argument with nymphs, the shepherd Cerambus was transformed into a large beetle with horns.
Staphyliniformia is a large infraorder of beetles. It contains over 60,000 described species from all regions of the world. Most species occur in moist habitats - various kinds of rotting plant debris, fungi, dung, carrion, many live in fresh water.
Scarabaeoidea is a superfamily of beetles, the only subgroup of the infraorder Scarabaeiformia. Around 35,000 species are placed in this superfamily and some 200 new species are described each year. Its constituent families are also undergoing revision presently, and the family list below is only preliminary.
Cucujoidea is a superfamily of beetles. They include many fungus beetles, as well as lady beetles. Also included are a diversity of lineages of "bark beetles" unrelated to the "true" bark beetles (Scolytinae), which are weevils.
A bark beetle is one of about 220 genera with 6,000 species of beetles in the subfamily Scolytinae. Traditionally, this was considered a distinct family Scolytidae, but is now understood to be very specialized members of the "true weevil" family (Curculionidae). Well-known species are members of the type genus Scolytus, namely the European elm bark beetle S. multistriatus and the large elm bark beetle S. scolytus, which like the American elm bark beetle Hylurgopinus rufipes, transmit Dutch elm disease fungi (Ophiostoma). The mountain pine beetle Dendroctonus ponderosae, southern pine beetle Dendroctonus frontalis, and their near relatives are major pests of conifer forests in North America. A similarly aggressive species in Europe is the spruce ips Ips typographus. A tiny bark beetle, the coffee berry borer, Hypothenemus hampei is a major pest on coffee plantations around the world.
Bostrichoidea is a superfamily of beetles. It is the type superfamily of the infraorder Bostrichiformia.
Ochodaeidae, also known as the sand-loving scarab beetles, is a small family of scarabaeiform beetles occurring in many parts of the world.
The Megalopodidae are a small family of leaf beetles, previously included as a subfamily within the Chrysomelidae. One of its constituent subfamilies, Zeugophorinae, which contains a single genus, has also frequently been treated as a subfamily within Chrysomelidae. The family contains approximately 30 genera worldwide, primarily in the nominate subfamily Megalopodinae, and mostly circumtropical.
Glaphyridae is a family of beetles, commonly known as bumble bee scarab beetles. There are eight extant genera with about 80 species distributed worldwide and two extinct genera described from the fossil record of China.
Georissus, also called minute mud-loving beetles, is the only genus in the beetle family Georissidae. They are tiny insects living in wet soil, often near water. Found on every continent except Antarctica.
Schizopodidae is a family of beetles, in the large suborder Polyphaga. It was a subfamily until 1991, when it was elevated to family status.
Clambidae is a family of beetles. They are known commonly as the minute beetles or the fringe-winged beetles. They are found worldwide on every continent except Antarctica.
Coccinelloidea is a superfamily of beetles in the order Coleoptera. There are more than 10,000 species in Coccinelloidea, including more than 6000 in the lady beetle family Coccinellidae.
