Ampulicidae

The Ampulicidae, or cockroach wasps, are a small (about 170 species), primarily tropical family of sphecoid wasps, all of which use various cockroaches as prey for their larvae. They tend to have elongated jaws, pronounced neck-like constrictions behind the head, strongly petiolate abdomens, and deep grooves on the thorax. Many are quite ant-like in appearance, though some are brilliant metallic blue or green.