Common Ground Beetle

Family Carabidae — the ground beetles — contains over 40,000 described species worldwide and is one of the most species-rich beetle families. The vast majority of carabids are nocturnal predators that hunt soft-bodied invertebrates on the soil surface and in leaf litter — caterpillars, slugs, snails, root maggots, fly larvae, springtails, and many other small arthropods. Many species are also significant weed-seed predators (granivory): some Harpalus, Amara, and Anisodactylus species consume thousands of weed seeds per square meter per year, providing important agricultural biocontrol. Ground beetles are among the most studied indicator species in conservation biology — community composition reflects habitat quality, soil health, and pesticide exposure history. Many large carabid species are brilliantly iridescent: Carabus auratus (the golden ground beetle of central and southern Europe) is metallic green-gold-copper; Cicindela tigerbeetles are iridescent green and blue. Bombardier beetles (Brachininae, ~500 species) are a remarkable subgroup that can superheat hydroquinone and hydrogen peroxide in a chamber to 100°C and spray the resulting boiling reaction onto attackers. Most carabid species require persistent litter and soil-surface microhabitat that is destroyed by tillage and pesticide use; ground beetle conservation has driven the development of 'beetle banks' (linear strips of permanent grass within agricultural fields that provide overwintering habitat).