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Wheel Bug

Arilus cristatus


"The wheel bug (Arilus cristatus), in the family Reduviidae, is one of the largest terrestrial true bugs in North America, being up to 1.5 inches, or 38 mm, in length; it is the only member of its genus. A characteristic structure is the wheel-shaped pronotal armor. They are predators upon soft-bodied insects such as caterpillars, Japanese beetles, etc., which they pierce with their beak to inject salivary fluids that dissolve soft tissue. Because most of their prey are pests, wheel bugs are considered beneficial insects, although they can inflict a painful bite if handled carelessly."


"Wheel bugs are common in eastern North America, although many people in the region have never seen them. They are camouflaged and very shy, hiding whenever possible. They have membranous wings, allowing for clumsy, noisy flight which can easily be mistaken for the flight of a large grasshopper. The adult is gray to brownish gray in color and black shortly after molting, but the nymphs (which do not yet have the wheel-shaped structure) have bright red or orange abdomens."


"The wheel bug has characteristic dorsal armor, shaped like a wheel or cog. It moves and flies slowly, and in flight produces a buzzing sound. It has one of the most developed set of mouth parts among true bugs. Its beak arises from the anterior end of its long, tubular head and unfolds forward. The bug plunges its beak into its victim, pinning its prey with its front legs. It then injects enzymes into the victim, paralyzing it and dissolving its insides, and proceeds to drain all of the victim's bodily fluids. The bite of a wheel bug is painful and may take months to heal (sometimes leaving a small scar), so caution is advised when handling them. The wheel bug is also noted to be very vicious in the wild, and cannibalistic behaviors between them have been noted; for example, nymphs may prey on nymphs and the female may feed on the male after mating is concluded. It possesses two scent sacs (red-orange in color) that can be fired from its anus, usually in reaction to being disturbed. The scent produced by it is not as powerful as that produced by the stink bug, but is still strong enough to be detected by human noses. Colors include black and gray. [edit]Reproduction The reproductive cycle of the wheel bug initiates in autumn. When a pair of wheel bugs encounter each other and mate, the female will lay 40-200 small, brown, cylindrical eggs on a tree twig, and eventually die. The eggs will hatch in the next spring into eighth-inch long red nymphs, which will undergo 5 molts and metamorphose until they reach the adult stage the following summer."

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MichaelMorris 11 years ago

great info, i saw these a lot in cinci,, your pic is way better than the one i got

HeatherMiller 11 years ago

Wow - your comments are incredibly detailed. I thought of those insect-eats-NeyYork type of movies when I saw this picture. It is pretty neat.

jamerbean 12 years ago

Thanks for the information on the nymphs! I looked up a picture and they look exactly like the bugs I saw in the spring that I could never identify when I lived in Georgia.

Latimeria 12 years ago

I love all the wheel bug spottings that are being submitted! I'm going to be studying these guys during the summer, and it's great to get a better feel for their distribution. Let me know if you find more!

harpster84 12 years ago

thanks :)

lori.tas 12 years ago

An excellent profile view, which really shows off the "wheel" for which it is named.

Spotted by

Cincinnati, Ohio, USA

Spotted on Aug 2, 2009
Submitted on Apr 2, 2011

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