The wheel bug (Arilus cristatus) is in the family Reduviidae (literally, "hangnail"), which consists of assassin bugs. The species is one of the largest terrestrial true bugs in North America, reaching up to 1.5 inches (38 mm) in length in their adult stage. However, males are smaller in terms of their length and width when compared to females. A characteristic structure is the wheel-shaped pronotal armor. They are predators upon soft-bodied insects such as caterpillars, Japanese be (Wikipedia)