FaunaHub

Beetle (order Coleoptera)

InvertebrateInsectMost diverse order

Male European stag beetle (Lucanus cervus) with large jaw-like mandibles.

European stag beetle (Lucanus cervus), male.

Image: Holger Krisp, CC BY 4.0, via Wikimedia Commons.

Overview

Beetles (order Coleoptera) make up the most species-rich group of animals on Earth — by described species, more kinds of beetle are known than of any other animal order. Their defining feature is a pair of hardened front wings, called elytra, that fold over the back like a protective case and meet in a straight line down the middle. The reference species shown here is the European stag beetle (Lucanus cervus).

From tiny species to large, horned giants, beetles occupy nearly every land and freshwater habitat and fill an enormous range of ecological roles.

Note: beetles are extraordinarily diverse, and exact species totals vary by source and keep rising as new species are described. Figures should be treated as approximate.

Habitat & Range

Beetles are found almost everywhere on land and in fresh water, from forests, grasslands, and deserts to ponds and streams, and from the tropics to cold regions. Different beetles live in soil, leaf litter, wood, dung, fungi, flowers, and many other microhabitats.

Diet

As a group, beetles eat almost anything. There are plant-eaters that feed on leaves, roots, seeds, wood, or pollen; predators that hunt other invertebrates; scavengers and recyclers that consume dung, carrion, and decaying matter; and fungus-feeders. This dietary range is part of why beetles are so successful.

Behavior

Beetles undergo complete metamorphosis, passing through egg, larva, pupa, and adult stages — the larvae often look completely different from the adults and may live in different places. Many beetles can both walk and fly, unfolding membranous hind wings from beneath the elytra. Behaviours range from the dung-rolling of dung beetles to the light displays of fireflies (which are beetles).

Human Interaction & Conservation

Beetles matter enormously to people and ecosystems: dung beetles and carrion beetles recycle waste, many beetles pollinate plants or control pests, and others are themselves crop pests or wood-borers. Most species are harmless and ecologically valuable. As with all invertebrates, habitat loss and pesticide use are broad concerns. Consult authoritative sources for specific species.

More photos of the beetle

Female stag beetle on wood.

Stag beetle (Lucanus cervus), female.

Image: Frank Vassen from Brussels, Belgium, CC BY 2.0, via Wikimedia Commons.

Frequently Asked Questions — Beetle

Why are there so many kinds of beetle?
Beetles are the most species-rich order of animals, with more described species than any other. Their success is linked to features like protective wing cases, complete metamorphosis, the ability to exploit almost every habitat and food source, and a long evolutionary history — together these have allowed beetles to diversify enormously.
What are a beetle's hard wing cases?
The hardened front wings are called elytra. They protect the delicate flying hind wings and the body, and meet in a straight line down the back — a key way to recognise a beetle. To fly, a beetle lifts the elytra and unfolds the membranous hind wings beneath.
Are fireflies and ladybugs beetles?
Yes. Both are beetles. Fireflies (which produce light) and ladybugs/ladybirds (often helpful aphid predators) are members of the order Coleoptera, despite their very different appearances.
What do beetles eat?
It depends on the species. Beetles include plant-eaters, predators of other invertebrates, scavengers that recycle dung and carrion, and fungus-feeders. This huge dietary range is one reason beetles are found almost everywhere.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.