Beetles

Beetles are insects in the order Coleoptera, the largest group of animals by described species. Estimates place around 400,000 beetle species, with total diversity likely higher. They live in nearly all habitats, from forests to deserts and freshwater, and perform a wide range of ecological roles.

A defining feature is the pair of hardened forewings, the elytra, which cover the hind wings and abdomen. Beetles have chewing mouthparts and undergo complete metamorphosis: egg, larva, pupa, adult. Larvae are diverse in form and habit, often living in wood, soil, or detritus.

Ecology and roles: Beetles occupy many niches as decomposers, herbivores, predators, and parasites. They contribute to nutrient cycling, pollination in some species, and prey on other insects. Some lineages are pests to crops or stored products, while others are beneficial biological control agents, such as lady beetles and predatory ground beetles.

Classification: Major suborders include Adephaga and Polyphaga; well-known families include Carabidae (ground beetles), Scarabaeidae (scarabs), Curculionidae (weevils), Cerambycidae (longhorn beetles), and Coccinellidae (lady beetles). Beetles exhibit extensive diversity in size, color, and life history, including wood borers, leaf miners, and aquatic forms.

Evolution and human impact: Beetles have a long fossil record, with major diversification linked to flowering plants. They interact with humans as pests or beneficial organisms. Conservation concerns focus on habitat loss and climate change, which threaten many species, including specialized wood and forest beetles.