02/13/2021
Today we're looking at The Wheel Bug, which has a curious physical feature.
The wheel bug is a species of large assassin bug in the family Reduviidae. The species is one of the largest terrestrial true bugs in North America, reaching up to 1.5 inches in length in their adult stage. They are sexually dimorphic, in that males are somewhat smaller than the females.
Order: True bugs
Scientific name: Arilus cristatus
Higher classification: Arilus
Phylum: Arthropoda
Rank: Species
Family: Reduviidae
A characteristic structure is the wheel-shaped pronotal armor. Wheel bugs prey on caterpillars and beetles, such as Japanese beetles, the cabbage worm, orange dogs, tent caterpillars, and the Mexican bean beetle, all of which they pierce with their beak to inject salivary fluids that dissolve soft tissue. Wheel bugs are most active in daylight, though they may engage in predatory behaviors at night in areas illuminated by lights. Because most of their prey are pests, wheel bugs are considered beneficial.
They are camouflaged and very shy, residing in leafy areas and hiding whenever possible. Specifically, habitats of the wheel bug include sunflowers, goldenrod, cotton, trunks of locust trees, and various fruit and tree groves. 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. It was described in 1763 by Carl Linnaeus. Despite the prevalence of the wheel bug in many habitats, the information compiled concerning the species is haphazard and incomplete.
The wheel bug has a characteristic dorsal crest, shaped like a wheel or cog. It moves and flies slowly, and in flight produces a noisy buzzing sound. As with other assassin bugs, its proboscis arises from the anterior end of its long, tubular head and unfolds forward when feeding.
It possesses two scent glands (red-orange in color) that can be ejected from its abdomen, usually in reaction to being disturbed. The scent produced by it is not as powerful as that produced by stink bugs, but is still strong enough to be detected by humans.
Wheel bugs exhibit armored forewings and membranous hind wings which allow the wheel bug to take flight. As a result of its inability to move swiftly, wheel bugs rely heavily upon camouflage, the effect of their bite, or the production of unpleasant odors in order to avoid predation.
