Calosoma

Calosoma is a genus of large ground beetles, family Carabidae, occurring primarily throughout the Northern Hemisphere and known as caterpillar hunters or caterpillar searchers, comprising roughly 167 species. Members are recognizable by a large thorax nearly as wide as the abdomen and much wider than the head, predominantly black coloring though some species show metallic hues, and glands near the tip of the abdomen that produce a foul-smelling defensive spray. Both larvae and adults are voracious consumers of caterpillars, making the genus generally considered beneficial for pest control, and some species are especially common in areas such as California.