Species Arilus cristatus - Wheel Bug

Arilus cristatus (Linnaeus, 1763)

Species name cristatus is Latin for "crested"

The common name derives from the coglike projection on the back of the mature insect.

Of four Arilus species listed in the New World, this is the only one reported in the US.

Perhaps the largest North American assassin bug--the mature adult is 28-36 mm long (1), with females being larger than males.

The "wheel" on the adult insect's back is unmistakable. Immature nymphs are mostly red. Adults are gray to brown.

Widespread: Ontario, New York, west through Iowa & Nebraska to New Mexico, California, South to Texas and Florida. Also reported from Mexico, Guatemala (Hagerty and McPherson, 2000).

Found where prey is abundant: adults often lurk on composite (daisy-like) flowers attractive to insects, or prowl in trees where caterpillars are plentiful.

Nymphs hatch in spring, adults are found late spring into fall and early winter.

All stages prey upon other insects - caterpillars, aphids, bees, sawflies etc. - and are thus considered beneficial.

One generation occurs per year. Adults mate in fall, the male then guards the female

since other males may try to move in .

Clusters of eggs (described as "brown bottles with fancy stoppers") are laid in hexagonal clusters of 42-182 on trees, shrubs or other structures, generally within 4 feet of the ground

.

Here's a great series from Jim Kramer on eggs and hatching (more in the guide):

After eggs hatch in spring , nymphs develop slowly. They must

watch out for predators including their own brethren!

and

(about 3 months to maturity): red/black

;

red/grey

;

grey/black

.

They hunt down their prey such as this one walking on a Hyphantria tent

and attack

They have a heavy beak for feeding ,

pierce their prey and eat

.

They need to molt in order to grow, described by one contributor as looking like an orange bug with a spider stuck on its tail!

.

Which can be fatal if they can't extricate themselves:

Adults are generally not seen until May even in warmest parts of US

Some are unfortunate victims of parasitoids .

Others thrive, sometimes even with deformed wheels ,

reproduce,and the cycle begins again. Adults may survive into December in warmest regions.

CAUTION: the adult wheelbug is reported to inflict a very painful bite. Featured Creatures (see below for link) reports that ammonia water and magnesium sulphate soaks can be helpful in relieving pain from the bite. Perhaps (like fire ant bites), quick treatment with an ammonia-based household cleaner may be effective if you have been bitten. See Lynette's list of fire ant remedies here for some other suggestions - and please comment if you have any experience with these bites.