Ground beetles are generalist predators with powerful jaws that feed on nearly any soil-dwelling insect. There are many species of ground beetle, usually found under debris, in soil cracks, or moving quickly along the ground. Adult ground beetles are mostly black or brown with ridged wing covers and have long legs. Their abdomen is usually shiny and hard and have long antennae. Adults vary in size, depending on species.
Larvae live in leaf litter on the ground or in the topsoil. They have elongated bodies and distinct, curved mouthparts that extend from the head. Pupae are brown to yellow and are rarely observed since they pupate underground in a soil cell.
- Adults and larvae are voracious predators and feed on a wide variety in insect pests such as caterpillars, millipedes, slugs, and snails.
- Typically, the adults are fast runners and rarely fly. Some species have fused forewings (elytra) and have lost the ability to fly completely.
- Although adults can enter homes, they are accidental invaders and do not feed or reproduce indoors and should be placed back outside if caught.
Life history and habits
Ground beetles have four life stages: egg, larva, pupa, and adult. These beetles can take up to one year to reach adulthood, and adults can live for two years or more. The development time varies depending on location and species.
Adult females lay eggs in soil, and the emergent larvae dwell in organic litter or in topsoil. Larvae develop through four instars before reaching adulthood. During the last instar, mature larvae will form a cell in the soil where they pupate.
Ground beetles provide essential biological control in gardens and fields. Therefore, applications of broad-spectrum insecticides should be avoided where ground beetles are present.
On occasion, the ground beetles can make their way into homes and can become a nuisance pest. However, they do not reproduce indoors and should be returned outside if caught.
UCIPM. (n.d.). Predaceous Ground Beetles. University of California Agriculture and Natural Resources. Available https://ipm.ucanr.edu/natural-enemies/predaceous-ground-beetles/
USU (n.d.). Ground Beetles. Utah State University – Extension. Available https://extension.usu.edu/pests/schoolipm/structural-pest-id-guide/ground-beetles
Varenhorst, A. 2023. Ground Beetles: Predators That Provide Benefits in Agricultural Landscapes. Available https://extension.sdstate.edu/ground-beetles-predators-provide-benefits-agricultural-landscapes