Sample of the week (January 28, 2019):
Ground Beetle

Ground beetle

Adult ground beetles

Ground beetles make up the largest group of insects in the order Coleoptera belonging to the family Carabidae. They are small to moderate in size measuring between 1/8 and 3/4 inches long and they vary in shapes and colors. They are commonly found in different environments such as forests, landscapes and fields. They are attracted to light and sometimes can become a nuisance when they occur in large numbers inside houses and buildings. These beetles wander into buildings through cracks and openings and can be found in hidden damp areas. Ground beetles can be confused with cockroaches, carpet beetles or other household pests.

The beetles live temporarily indoors and do not establish there. Female adults lay eggs in soil, upon hatching the larvae pupate and overwinter in the soil. Adult ground beetle emerge in the spring and some can live for several years. Most ground beetles complete their developmental stages within 1 year.

Ground beetles do not cause any damage to buildings and furniture, and they are not harmful to human and pets. Most larvae and adult ground beetles are beneficial by feeding on other insects, and therefore control is not necessary. However, in circumstances where these beetles are nuisance pests in buildings, non-chemical strategies such as sealing and repairing points of entry, eliminating hiding places (i.e. mulch, stones, plant debris, tall grasses and weeds) around the home can be helpful in mitigating invasion. In extremely severe cases, spraying insecticide around the house foundation, doorways and other points of entry may be necessary.

For appropriate identification, the MU Plant Diagnostic Clinic can help you confirm your insect species and provide you with the best way to manage them. Please visit our website and follow the instructions for collecting, packaging and shipping samples to the clinic.

For more information on ground beetles, see the article by Penn State's Department of Entomology: