Calosoma sycophanta, the forest caterpillar hunter, is a species of ground beetle belonging to the family Carabidae.

These colours have iridescent shades that change (green, blue, bronze, copper, gold black) according to the direction and quality of light.

Pronotum is transverse shaped, posteriorly sharply narrowed, wrinkled and punctured.

[2] This ground beetle is a voracious consumer of caterpillars (especially Lymantria dispar, Thaumetopoea processionea, Thaumetopoea pityocampa and Euproctis chrysorrhoea) during both its larval stage and as an adult.

[3][4][5][6] As a predator the species has been researched for the effect of its predation upon the caterpillars with microsporidian pathogens, finding a preference for Vairimorpha disparis infected larva.