Ground Beetles – Family Carabidae
Beetles in the Coleoptera family Carabidae are commonly known as “ground beetles.” Ground beetles are usually active nocturnal hunters, with the notable exception of the subfamily Cicindellidae (Tiber Beetles) which are almost all diurnal. There are more than 22,000 species worldwide and approximately 2,500 in North America. The adult beetles range from 1/8 inch to 1¼ inches long.
Variable in shape, they are usually elongate, heavy bodied, and slightly or distinctly tapered at the head end. While generally dark in color (dark brown to black), some beetles are an attractive purple or metallic green, or are multi-colored, as in the case of some tropical species.
Live adult ground beetles photographed at Winfield, Illinois, USA.
Larval ground beetles are elongate and wormlike in appearance; most live in burrows in the soil or in leaf litter or other debris. Both larval and adult ground beetles have powerful and prominent mandibles. Most ground beetles feed on a varied diet of insects, many of which are garden or house pests such as cutworms or house fly maggots. One specific group of ground beetles feeds on snails and slugs. A few species feed on pollen or seeds.
Order Coleoptera: Beetles are the dominant form of life on earth: one of every five living species is a beetle. Coleoptera is the largest order in the animal kingdom, containing a third of all insect species. There are about 400,000 known species worldwide, ~30,000 of which live in North America. Beetles live in nearly every habitat, and for every kind of food, there’s probably a beetle species that eats it.