Coleoptera is the largest order of insects, with over 400,000 species of beetles and weevils, representing about 40 percent of known insect species and about 25 percent of all known animal species. They are found in nearly all climates and latitudes, excluding extreme environments like Antarctica. Beetles attract attention for many reasons, including economic importance, size, abundance, appearance, and remarkable habits. Most beetles have two pairs of wings; the front pair is modified into hard covers called elytra that protect the rear pair and most of the abdomen. The four developmental stages of Coleoptera—egg, larva, pupa, adult—constitute complete metamorphosis.

What is the common name for insects in the order Coleoptera?

Insects belonging to the order Coleoptera are commonly known as beetles . This order is the largest among insects and within the animal kingdom, comprising approximately 40 percent of all known insect species, with over 400,000 species of beetles and weevils. Beetles are found in almost all climates and latitudes across the world. Beetles are known for having two pairs of wings, where the front pair has evolved into hardened, protective covers called elytra. The elytra usually meet in a straight line down the beetle's back, shielding the rear wings and abdomen.

What are some main physical characteristics of beetles?

Beetles (Coleoptera) exhibit a wide array of structural modifications, making generalizations challenging. Their segmented bodies consist of a head, thorax, and abdomen. The exoskeleton varies from rigid to flexible, featuring hard plates (sclerites) separated by flexible membranes. Key characteristics include: * Wings Most beetles have two pairs of wings; the front pair, called elytra, serve as protective covers. Some species have reduced or absent wings. * Antennae Usually 11-segmented, but vary widely in form. * Jaws (mandibles) can be large or almost completely absent, typically triangular for biting or chewing. * Legs Modified for various functions like running, swimming, jumping, or digging. * Size They vary greatly in size, from a fraction of a millimeter to more than 200 mm in length.

How do beetles differ from other types of insects?

Beetles, belonging to the order Coleoptera , stand out from other insects due to their distinctive wing structure. The front wings of beetles are hardened or leathery and are called elytra , acting as protective covers for the delicate hindwings, which are used for flying. Other distinguishing features of beetles include their mouthparts , which are adapted for chewing, and their complete metamorphosis encompassing egg, larva, pupa, and adult stages. With over 400,000 species, Coleoptera is the largest insect order, representing about 40% of all known insect species.

Where can beetles be found in nature?

Beetles (order Coleoptera) are the largest insect order, with over 400,000 species, representing about 40 percent of known insect species and the largest animal order. They are found in nearly all climates and latitudes, except in extreme environments like Antarctica and the highest altitudes. While many species thrive in temperate environments, the greatest number of species is found in the tropics. Beetles can be solitary or found in aggregations. Ground beetles, long-horned wood-boring beetles, and weevils are often solitary, while ladybugs, leaf beetles, pleasing fungus beetles, darkling beetles, checkered beetles, bess beetles, sap beetles, and some scarab beetles frequently gather in groups. They live in almost all types of habitats and have a worldwide distribution. Many beetles have adapted to aquatic environments, while others live with ants and termites.

What roles do beetles play in the environment and ecosystems?

Beetles, belonging to the order Coleoptera, play diverse and crucial roles in various ecosystems. They contribute significantly to the environment through:

Coleoptera

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Images, Videos & Interactives

Illustration showing eleven different beetle species, each labeled with common and scientific names, including European rhinoceros beetle, clover seed weevil, great silver water beetle, violet ground beetle, longhorn beetle, green tiger beetle, seven-spotted ladybug, stag beetle, click beetle, deathwatch beetle, and glowworm. Each beetle is depicted in color and detail, highlighting their varied shapes and markings.

Illustration showing seven types of beetle larvae, each with distinct shapes and textures, including white grub, linden borer, water-penny, aquatic beetles, carpet beetle, and buprestid larva, with scientific names labeled.

Coleoptera

insect

Also known as: beetle, coleopteran

Written by

Judson Linsley Gressitt

Fact-checked by

Britannica Editors

Last updated

Oct. 16, 2026 •History

Top Questions

What are Coleoptera?
Coleoptera is the largest order of insects, with over 400,000 species of beetles and weevils, representing about 40 percent of known insect species and about 25 percent of all known animal species. They are found in nearly all climates and latitudes, excluding extreme environments like Antarctica.

Beetles attract attention for many reasons, including economic importance, size, abundance, appearance, and remarkable habits. Most beetles have two pairs of wings; the front pair is modified into hard covers called elytra that protect the rear pair and most of the abdomen. The four developmental stages of Coleoptera—egg, larva, pupa, adult—constitute complete metamorphosis.
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1. Coleoptera
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What is the common name for insects in the order Coleoptera?
Insects belonging to the order Coleoptera are commonly known as beetles. This order is the largest among insects and within the animal kingdom, comprising approximately 40 percent of all known insect species, with over 400,000 species of beetles and weevils. Beetles are found in almost all climates and latitudes across the world.

Beetles are known for having two pairs of wings, where the front pair has evolved into hardened, protective covers called elytra. The elytra usually meet in a straight line down the beetle's back, shielding the rear wings and abdomen.
1 Britannica Source
1. Coleoptera
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What are some main physical characteristics of beetles?
Beetles (Coleoptera) exhibit a wide array of structural modifications, making generalizations challenging. Their segmented bodies consist of a head, thorax, and abdomen. The exoskeleton varies from rigid to flexible, featuring hard plates (sclerites) separated by flexible membranes.

Key characteristics include:
* Wings Most beetles have two pairs of wings; the front pair, called elytra, serve as protective covers. Some species have reduced or absent wings.
* Antennae Usually 11-segmented, but vary widely in form.
* Jaws (mandibles) can be large or almost completely absent, typically triangular for biting or chewing.
* Legs Modified for various functions like running, swimming, jumping, or digging.
* Size They vary greatly in size, from a fraction of a millimeter to more than 200 mm in length.
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Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
How do beetles differ from other types of insects?
Beetles, belonging to the order Coleoptera, stand out from other insects due to their distinctive wing structure. The front wings of beetles are hardened or leathery and are called elytra, acting as protective covers for the delicate hindwings, which are used for flying.

Other distinguishing features of beetles include their mouthparts, which are adapted for chewing, and their complete metamorphosis encompassing egg, larva, pupa, and adult stages. With over 400,000 species, Coleoptera is the largest insect order, representing about 40% of all known insect species.
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1. insect: Annotated classification
2. Coleoptera
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Where can beetles be found in nature?
Beetles (order Coleoptera) are the largest insect order, with over 400,000 species, representing about 40 percent of known insect species and the largest animal order. They are found in nearly all climates and latitudes, except in extreme environments like Antarctica and the highest altitudes.

While many species thrive in temperate environments, the greatest number of species is found in the tropics. Beetles can be solitary or found in aggregations. Ground beetles, long-horned wood-boring beetles, and weevils are often solitary, while ladybugs, leaf beetles, pleasing fungus beetles, darkling beetles, checkered beetles, bess beetles, sap beetles, and some scarab beetles frequently gather in groups.

They live in almost all types of habitats and have a worldwide distribution. Many beetles have adapted to aquatic environments, while others live with ants and termites.
1 Britannica Source
1. Coleoptera
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What roles do beetles play in the environment and ecosystems?
Beetles, belonging to the order Coleoptera, play diverse and crucial roles in various ecosystems. They contribute significantly to the environment through:
- Decomposition Assisting in breaking down organic matter and aiding soil formation.
- Pollination Some beetles incidentally transfer pollen while feeding, particularly in certain flowers.
- Herbivory Many beetle larvae and adults feed on plant materials, influencing plant communities.
- Predation Predatory beetles control populations of other insects, while some beetle larvae act as predators in various habitats.
- Scavenging Certain beetles feed on dead animals and decaying matter.
- Symbiotic Relationships Some beetles live in association with ants, termites, and fungi, contributing to nutrient cycling and habitat modification.
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boll weevilAdult boll weevil (*Anthonomus grandis*).

Coleoptera, (order Coleoptera), insect order comprising more than 400,000 species of beetles and weevils. It is the largest order of insects, representing about 40 percent of the known insect species, and the largest animal order. Coleopterans are many of the largest and most conspicuous insects, some of which also have brilliant metallic colors, showy patterns, or striking form. Beetles can usually be recognized by their two pairs of wings; the front pair is modified into horny covers (elytra) that hide the rear pair and most of the abdomen and usually meet down the back in a straight line. Coleoptera occur in nearly all climates. They may be divided into four groups: the first three, the Archostemata, the Adephaga, and the Myxophaga, contain relatively few families; the majority of beetles are placed in the fourth group, the Polyphaga.

Beetles attract attention for many different reasons, including their economic importance, size, abundance, appearance, and remarkable habits. Several groups of beetles (e.g., Lampyridae) are among the few terrestrial animals capable of producing light; members of several other families (e.g., Cerambycidae) can produce sound (stridulate). Most large beetles make a loud noise during flight, and many species, both large and small, are attracted to light at night. Some beetles (e.g., burying beetles of the family Silphidae and whirligig beetles of the family Gyrinidae) attract attention by their bizarre habits; others do so by their grotesque forms (e.g., Scarabaeidae). Many beetles have become adapted to an aquatic environment (e.g., Hydrophilidae); others (e.g., Thorictinae) live in association with ants and termites.

General features

Distribution and abundance

Beetles are found in nearly all climates and latitudes, except in such extreme environments as those in Antarctica and at the highest altitudes. They are found on subantarctic islands, close to the northern extremes in the Arctic, and on many mountaintops. Although many species occur in temperate environments, the number of species is greatest in the tropics; in general, individuals of a species are most abundant in temperate areas, and fewer individuals of more species are found in the tropics.

Some species are solitary; others occur in aggregations. Predators such as the ground beetles (Carabidae) are more apt to be found alone, as are many long-horned wood-boring beetles (Cerambycidae) and weevils (Curculionidae). Ladybugs (Coccinellidae), leaf beetles (Chrysomelidae), pleasing fungus beetles (Erotylidae), darkling beetles (Tenebrionidae), checkered beetles (Cleridae), bess beetles (Passalidae), sap beetles (Nitidulidae), and some species of scarab beetles (Scarabaeoidea) are often found in aggregations of one or several different species.

Most families contain both widely distributed species and some with very limited ranges. Wide distribution in this sense refers to a zoogeographical or faunal region; limited distribution, to a single valley, plain, island, altitude zone, or vegetation type on a mountain.

Sea otter (Enhydra lutris), also called great sea otter, rare, completely marine otter of the northern Pacific, usually found in kelp beds. Floats on back. Looks like sea otter laughing. saltwater otters

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Animal Group Names

Size range and diversity of structure

Coleoptera vary greatly in size, from a fraction of a millimeter to more than 200 mm (almost 8 inches) in length (e.g., rhinoceros beetle, Xyloryctes satyrus) and up to 75 mm (2.95 inches) in width (e.g., goliath beetle, Goliathus goliathus).

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Diversity of structure among adult beetles is as great as range of size. The ground beetles (Carabidae) have a rather generalized (primitive) form—the flattened, oval body has a relatively even surface, with regular ridges or grooves; antennae and legs are of moderate length and slender. The underside of most water beetles (Hydrophilidae) is oval, smooth, and flattened, the antennae either short or very slender, and the forelegs short and the hindlegs long and fringed with hairs that are used as paddles. Rove beetles (Staphylinidae) have very short elytra and a slender abdomen. Soldier beetles (Cantharidae), fireflies (Lampyridae), and net-winged beetles (Lycidae) have soft elytra.

Click beetles (Elateridae) have a hingelike joint in the body region called the thorax that enables them to snap their bodies and jump high in the air; their relatives, the Buprestidae (metallic wood borers), cannot jump but take flight very quickly. Cleridae (checkered beetles) are usually oblong or cylindrical, fairly active, and often brightly colored. Nitidulidae (sap beetles) are short and flattened and have slightly shortened elytra. Coccinellidae (ladybugs, ladybird beetles) are rounded, with a smooth, raised upper surface and a flat underside. The Endomychidae (handsome fungus beetles) often have enlarged, rounded elytra. The Erotylidae (pleasing fungus beetles) are usually slender, smooth, and shiny, as are the Languriidae.

Among the stout or cylindrical lamellicorns (Scarabaeoidea) are a number of bizarre forms. The male rhinoceros beetles (Dynastinae) have one or more horns on the head and sometimes on part of the thorax. Many of the true scarabs (Scarabaeinae) and other dung-feeding groups of the lamellicorns also have horns, including some of the goliath beetles (Cetoniinae). Male stag beetles (Lucanidae) have greatly enlarged mandibles (jaws); some are as long as the rest of the body.

The Chrysomelidae (leaf beetles) vary from simple egg-shaped forms to slender, flat, or wedge-shaped ones, with wide elytra in the tortoise beetles and often numerous spines or tubercles in the leaf-mining leaf beetles (Cassidinae). The Bruchinae (seed beetles, or bean weevils) are short and stumpy, with short stout legs. The head, slightly elongated in front, is similar to that of some curculionid weevils. The Cerambycidae (long-horned beetles), diverse in form and structure, usually have antennae that are longer than the body. Cerambycids may be slender and medium to large in size or very small.

The extremely diverse Tenebrionidae (darkling beetles) are not always recognized as members of one family. Most arboreal (tree-dwelling) forms in the tropics or subtropics are slender and long-legged. Some slender and egg-shaped forms have a metallic sheen; most of the ground-dwelling forms are black and robust. The large tropical Trictenotomidae resemble some cerambycids (Prioninae) but are not related to them. The Alleculinae (comb-clawed beetles) resemble some of the slender tenebrionids but are usually more active. Lagriinae (lagriids) have a characteristic shape, usually widened behind, and sometimes a metallic sheen. Colydiinae (cylindrical bark beetles), hard-bodied and shiny or roughened, may be cylindrical and somewhat flattened.

The Curculionidae (weevils) range from slender to stout, elongated to egg-shaped; the bodies of some species contain many rounded projections (tubercles), and those of others may be smooth or grooved. The mouth is located on the end of a snoutlike projection, which varies in shape from short and stout to long and slender and sometimes exceeds the length of the rest of the body. Some Anthribidae (fungus weevils), usually cylindrical in shape, have slender antennae that may be longer than the rest of the body; they are easily confused with the cerambycids. Brentidae (primitive weevils) usually are long and slender with antennae projecting from the sides of the snout. Scolytinae (bark beetles, ambrosia beetles) do not have a distinct snout and are usually cylindrical in shape, as are Platypodinae.

Coleoptera

General features

Distribution and abundance

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Size range and diversity of structure