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).
Stag beetles are a group of about 1,200 species of beetles in the family Lucanidae, presently classified in four subfamilies. Some species grow to over 12 cm (4.7 in), but most are about 5 cm (2.0 in).
Ground beetles are a large, cosmopolitan family of beetles, Carabidae, with more than 40,000 species worldwide, around 2,000 of which are found in North America and 2,700 in Europe. It is one of the ten most speciose animal families, as of 2015.
The insects of the beetle family Chrysomelidae are commonly known as leaf beetles, and include over 37,000 species in more than 2,500 genera, making up one of the largest and most commonly encountered of all beetle families. Numerous subfamilies are recognized, but only some of them are listed below. The precise taxonomy and systematics are likely to change with ongoing research.
The rove beetles are a family (Staphylinidae) of beetles, primarily distinguished by their short elytra that typically leave more than half of their abdomens exposed. With roughly 63,000 species in thousands of genera, the group is currently recognized as the largest extant family of beetles. It is an ancient group, with fossilized rove beetles known from the Triassic, 200 million years ago, and possibly even earlier if the genus Leehermania proves to be a member of this family. They are an ecologically and morphologically diverse group of beetles, and commonly encountered in terrestrial ecosystems.
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.
Dung beetles are beetles that feed partly or exclusively on feces (dung). A dung beetle can bury dung 250 times heavier than itself in one night.
Polyphaga is the largest and most diverse suborder of beetles. It comprises 144 families in 16 superfamilies, and displays an enormous variety of specialization and adaptation, with over 300,000 described species, or approximately 90% of the beetle species so far discovered.
Darkling beetle is the common name of the large family of beetles, Tenebrionidae. The number of species in the Tenebrionidae is estimated at more than 20,000 and the family is cosmopolitan in distribution.
Buprestidae is a family of beetles known as jewel beetles or metallic wood-boring beetles because of their glossy iridescent colors. Larvae of this family are known as flatheaded borers. The family is among the largest of the beetles, with some 15,500 species known in 775 genera. In addition, almost 100 fossil species have been described.
Histeridae is a family of beetles commonly known as Clown beetles or Hister beetles. This very diverse group of beetles contains 3,900 species found worldwide. They can be easily identified by their shortened elytra that leaves two of the seven tergites exposed, and their elbowed antennae with clubbed ends. These predatory feeders are most active at night and will fake death if they feel threatened. This family of beetles will occupy almost any kind of niche throughout the world. Hister beetles have proved useful during forensic investigations to help in time of death estimation. Also, certain species are used in the control of livestock pests that infest dung and to control houseflies. Because they are predacious and will even eat other Hister beetles, they must be isolated when collected.
Dermestidae are a family of Coleoptera that are commonly referred to as skin beetles. Other common names include larder beetle, hide or leather beetles, carpet beetles, and khapra beetles. There are approximately 500 to 700 species worldwide. They can range in size from 1 to 12 mm. Key characteristics for adults are round oval shaped bodies covered in scales or setae. The (usually) clubbed antennae fit into deep grooves. The hind femora also fit into recesses of the coxa. Larvae are scarabaeiform and also have setae.
Elateriformia is an infraorder of polyphagan beetles. The two largest families in this group are buprestids, of which there are around 15,000 described species, and click beetles, of which there are around 10,000 described species.
Derodontidae is a family of beetles, in its own superfamily, Derodontoidea, sometimes known as the tooth-necked fungus beetles. Beetles of this family are small, between 2 and 6 mm in length, with spiny margins on their pronotum that give them their name. The genus, Laricobius, lacks these spines. They have two ocelli on the top of their heads.
The family Prostomidae is a small group of beetles with no vernacular common name, though recent authors have coined the name jugular-horned beetles. They are often found in dead wood. The family consist of two genera with about 20 species. Prostomis mandibularis is known from North America. Other species of Prostomis are found in Africa, the Pacific region and East Asia. Species of Dryocora are known from New Zealand, Australia and Tasmania.
Cleridae are a family of beetles of the superfamily Cleroidea. They are commonly known as checkered beetles. The family Cleridae has a worldwide distribution, and a variety of habitats and feeding preferences.
The Bostrichidae are a family of beetles with more than 700 described species. They are commonly called auger beetles, false powderpost beetles, or horned powderpost beetles. The head of most auger beetles cannot be seen from above, as it is downwardly directed and hidden by the thorax. Exceptions are the powderpost beetles, and members of the subfamily Psoinae.
Coccinellidae is a widespread family of small beetles ranging in size from 0.8 to 18 mm. The family is commonly known as ladybugs in North America, and ladybirds in Britain and other parts of the English-speaking world. Entomologists widely prefer the names ladybird beetles or lady beetles as these insects are not classified as true bugs.
Bothrideridae is a family of beetles in the suborder Polyphaga. They are known commonly as the cocoon-forming beetles or dry bark beetles. They occur worldwide with most native to the Old World tropics.
