Ground Beetles and Tiger Beetles
Ground beetles, many species, Carabidae
Tiger beetles, Megacephala and Cicindela species, Cicindelidae
COLEOPTERA


DESCRIPTION

Adults -- Ground beetles are variable in size (3 to 25 mm), shape, and color. Most ground beetles have broad, hard wing covers with many parallel, longitudinal ridges. The prothorax is usually narrower than the abdomen, and the head is still narrower and directed forward. Mandibles are sickle-like. The antennae are 11-segmented and attached between the eyes and the bases of the mandibles. Most are black or dull brown in color, but some are metallic greens or blues. Some species have small, metallic spots of red or gold.

Tiger beetles are elongate, hard-bodied, long-legged, metallic blue, green, or bronze-colored beetles with sharp, sickle-shaped mandibles and large eyes. Length commonly varies from 10 to 20 mm. The head and thorax are narrower than the abdomen. The antennae are on the front of the head.

Eggs -- The eggs of ground beetles and tiger beetles are small, oval, and cream-colored.

Larva -- Ground beetles larvae are elongated, 10 to 45 mm long, slightly flattened, and taper toward the rear end. They have large heads with sickle-shaped mandibles that are directed forward.

Tiger beetles larvae are S-shaped and have strong spines. There is a hump with hooks on the fifth abdominal segment. Length varies from 20 to 50 mm. The head is large, dark in color and has strong jaws.

Pupae -- The pupae of ground beetles and tiger beetles resemble other beetle pupae.


BIOLOGY

Distribution -- Ground beetles and tiger beetles are found worldwide. About 2,000 tiger beetle species are known, many of which are tropical. Ground beetles are one of the largest beetle families with more than 20,000 known species. Adults of common southeastern species live on the ground. Ground beetle larvae can be found in soil, grass, and under bark or debris. Tiger beetle larvae live in vertical burrows in dry or sandy soil such as found in paths or beaches.

Hosts -- Both larvae and adults of ground beetles and tiger beetles are predaceous; a few ground beetle species feed on seeds and pollen or have mixed feeding habits. Both families include important enemies of many turf pests such as armyworms, cutworms, grubs, snails, and slugs.

Damage -- The adults of ground beetles and tiger beetles are sometimes nuisance pests when present in large numbers. Some species of ground beetles have been known to eat seeds and thus do occasional damage. However, economic damage by ground beetles in the Southeast is negligible.

Life History -- Most ground beetles complete a life cycle within a year. Ground beetles overwinter as larvae or adults. Eggs are deposited singly in the soil. Larvae develop in or on the soil, especially under stones, boards or other debris. Pupation takes place in the soil. Adults are usually nocturnal, and may be attracted to lights. Large numbers of adults are often found in areas where food is abundant.

Two or three years are usually required for tiger beetles to complete a life cycle. Eggs are deposited singly in chambers in the ground. Larvae live in the soil and may overwinter a meter or more below the soil surface. The larvae live in vertical tunnels. They lie in tunnel openings with heads out ready to attack prey that wanders by. The hooks on the fifth abdominal segment keep the larva from being pulled out of its burrow. Tiger beetles may also overwinter as adults. Tiger beetle adults are daytime feeders, but may be attracted to bright lights at night.


CONTROL

Ground beetles and tiger beetles are predators and are therefore considered beneficial. Control is usually not necessary, especially where turf is treated for other insects. Controlling the insects on which ground beetles and tiger beetles feed usually is sufficient to reduce the numbers of these predators.