I have been getting a lot of questions about Wheel Bugs this fall, for some reason. They are fairly big, and pretty unusual looking. Their most characteristic feature is a round, cog-looking wheel on their thorax.
They also move very slowly, which makes them easy to spot and follow.
Wheel Bugs are part of the Family of Assasin Bugs (Reduviidae), and are helpful insect predators. You definitely would like to have these in your garden. They’ll eat grasshoppers and caterpillars, among other insects.
They can give a painful poke if they are picked up, so don’t let kids handle them. Their beak, or mouth, is basically a straw for stabbing through an insect’s exoskeleton, and then sucking the innards out.
You can see a great series of photos at the BugGuide Wheel Bug Page!
(and thanks to zen for this very nice photo.)