Ground Beetles

image of Fiery Searcher on dead leaves
Scientific Name
About 2,400 species in North America north of Mexico
Family
Carabidae (ground beetles) in the order Coleoptera (beetles)
Description

Like other beetles, ground beetles have shell-like wing covers (elytra) that meet in a straight line over their abdomen. Ground beetles are usually black or brown, often shiny, and often have lengthwise grooves on the elytra. Some are quite colorful. The jaws are well-developed. The legs are long and slender, and most ground beetles are fast runners. Many are nocturnal and hide in dark places during the day. If uncovered, they run quickly to find new shelter. Some species emit or spray foul or irritating chemicals in defense.

Tiger beetles are a subfamily of ground beetles that are more often brightly colored and active during the daytime.

The larvae are segmented; black, brown, tan, or pale; and worm- or grublike; with six legs; and have strong pincers at the mouth. Sometimes there’s a hump behind the head. If you are familiar with mealworms, they are rather similar to those.

Size
Length: most are ¼ to ¾ inch, though some North American species reach 2 inches (varies with species).
Where To Find
image of Ground Beetles Distribution Map
Statewide.
Except for the tiger beetles, most ground beetles are nocturnal and seek dark places under debris. If you overturn a rock or log, you will probably see a few ground beetles rushing away. Most run along the ground, but they sometimes climb up trees seeking the caterpillars and other insects they eat. Many can fly and are attracted to lights at night. Some, notably the tiger beetles, are excellent daytime fliers and can been seen darting in and out of trails, sandbars, and other open areas.
Both larvae and adults are predators. The adults run down prey insects, snatching them with their strong jaws. Some species are excellent fliers and can capture flying insects. Different species prefer different prey. Many hunt for caterpillars; others prefer slugs and snails. Some also eat fruit or seeds, or scavenge from dead material, as well. The larvae of some species are parasitic on other insects.
The life cycles of this large family of beetles are as diverse as the beetles themselves. Like other beetles, they all undergo a complete metamorphosis, which means they have four growth stages: egg, larva (grub), pupa, and adult. As the larvae grow, they shed their skin a number of times until they are large enough to pupate. The adult (beetle) stage is the life stage when they are sexually mature. This is basically the same process that butterflies, flies, and bees go through.

Ground beetles are a great help to agriculture, since many of them feed on cutworms and other caterpillars and grubs that are injurious to crops. By feeding on larvae, they kill insects before they can reproduce.

People admire the iridescent colors of tiger beetles.

As predators, ground beetles help maintain the natural balance of insects in an ecosystem. Although many species use foul or pungent chemicals to ward off attackers, the larvae and eggs are vulnerable to many predators.
Media Gallery
image of Fiery Searcher on dead leaves
The fiery searcher or caterpillar hunter (Calosoma scrutator) eats caterpillars. A gorgeous ground beetle, it can emit a foul odor if harassed. It is about 1–1½ inches long. The wing covers are bright green with a reddish or golden border, and the pronotum (between head and wing covers) is purplish. Adults can live for three years.
Donna Brunet
1/4
image of a bronzed or common shore tiger beetle
The bronzed tiger beetle, or common shore tiger beetle (Cinindela repanda), is usually seen patrolling the shores of creeks, rivers, and other bodies of water, in open areas with sand, gravel, or clay soils. Adults fly in spring and early summer.
Donna Brunet
2/4
image of Six-Spotted Tiger Beetle crawling on dead leaves
The six-spotted tiger beetle (Cinindela sexguttata) is one of the most familiar tiger beetles in Missouri. It’s most often seen in spring, as it darts in and out of trails just ahead of hikers.
Donna Brunet
3/4
Brown beetle with white markings on its back and white hair-like structures on its legs and thorax
Submitted by Mark Beckemeyer
4/4
image of Fiery Searcher on dead leaves
image of a bronzed or common shore tiger beetle
image of Six-Spotted Tiger Beetle crawling on dead leaves
Brown beetle with white markings on its back and white hair-like structures on its legs and thorax
Similar Species
About Land Invertebrates in Missouri
Invertebrates are animals without backbones, including earthworms, slugs, snails, and arthropods. Arthropods—invertebrates with “jointed legs” — are a group of invertebrates that includes crayfish, shrimp, millipedes, centipedes, mites, spiders, and insects. There may be as many as 10 million species of insects alive on earth today, and they probably constitute more than 90 percent all animal species.