August 1996
SIZE: 1/4 to 1-1/2 inches (6.4-12.7mm)
COLOR: Mostly black although some are brightly colored
DESCRIPTION: There are a great number of species of these beetles, and some are rather ferocious looking-resulting in some very worried homeowners! These shiny, blackish brown beetles are predators on other insects and may enter houses in the spring looking for other insects (food). Ground beetles have well developed mandibles, but are not known to bite people. They use their strong mouthparts to devour other insects. The larval stages of ground beetles are also predators on insects, but they live in the grass and soil around the house.
HABITAT: Ground beetles are often found in houses in the spring. They may crawl around basements or ground floor rooms or fly to bright lights.
LIFE CYCLE: Female ground beetles lay eggs in the soil. Eggs hatch into larvae that feed in or on the soil under debris. Depending on the species, there may be several generations per year that invade the house if food becomes scarce or moisture conditions are unfavorable.
TYPE OF DAMAGE: There is no need to worry about these beetles permanently infesting a house. Both adults and larvae are beneficial because they feed on larvae of harmful insects.
CONTROL: Extensive control programs for these invaders are not recommended. Control in the house is done best with an aerosol spray or a fly swatter. There is no need to apply insecticides outside the house.
INTERESTING FACTS: Ground beetles are beneficial insects and an important part of the natural animal population in turf, pasture, and crop land. Some ground beetles are an important natural control of some insect pests of corn.