Animal profile

Wheel bug

Arilus cristatus

InsectaWoodland edge, orchards, gardens and scrub

Field profile

The wheel bug is a large grey assassin bug, up to about 35 millimetres, carrying a semicircular cog-toothed crest on the thorax that is unique among North American insects. It is a generalist predator of caterpillars, beetles and other insects, and delivers a painful defensive bite if handled.

Published field notes

2025-10-06

Wheel bug

The wheel bug digests its prey before drinking it

An assassin bug has no jaws to chew with. It stabs prey with a hinged beak, injects saliva that paralyses the victim and dissolves its tissues from within, then draws the liquefied contents back out through the same tube.

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