The more familiar species are up to 5 cm (2 in) long, making them among the largest of wasps, and have blue-black bodies and bright, rust-colored wings (other species have black wings with blue highlights). The vivid coloration found on their bodies, and especially wings, is an aposematism, advertising to potential predators the wasps' ability to deliver a powerful sting. Their long legs have hooked claws for grappling with their victims.