Number 2 • 2002 • Jeffrey K. Barnes

Caterpillar hunter
Order: Coleoptera
Family: Carabidae
Genus and species: Calosoma scrutator Fabricius

Caterpillar hunter

This brilliant, metallic green beetle is sometimes found in large numbers during the Arkansas spring, being attracted to lights at night. It may cause alarm because of its large size (it reaches 1 - 1½" in length) and the odor it emits to ward off predators and intruding humans. The wing covers have many fine longitudinal furrows that are beset with tiny punctures, and each cover has a reddish-copper border. The head, pronotum, and legs are deep metallic blue or purple, and the pronotum has a gold margin. Imprudent handlers could receive an unwelcome nip from the hefty mandibles. However, Calosoma scrutator is a highly beneficial species that climbs trees in search of caterpillar prey. Although the beetles are active from May to November, they seem to be especially numerous in May after trees are fully leafed out and while the spring flush of caterpillars is ravaging the foliage. Adults winter over, and they live up to 3 years. Eggs are placed one at a time in soil. Larvae also hunt caterpillars and climb trees and shrubs in search of prey. They pupate in earthen cells.

gray line