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Home » Guide » Arthropods (Arthropoda) » Hexapods (Hexapoda) » Insects (Insecta) » True Bugs, Cicadas, Hoppers, Aphids and Allies (Hemiptera) » True Bugs (Heteroptera) » Cimicomorpha » Assassin Bugs (Reduviidae) » Harpactorinae » Harpactorini » Wheel Bugs (Arilus) » North American Wheel Bug (Arilus cristatus)

Species Arilus cristatus - North American Wheel Bug

Classification · Other Common Names · Explanation of Names · Size · Identification · Range · Habitat · Season · Food · Life Cycle · Print References · Internet References · Works Cited

Wheel Bugs? - Arilus cristatus - male - female

Squash Bug or Assassin Bug Nymph - Arilus cristatus

Classification

Kingdom Animalia (Animals)

Phylum Arthropoda (Arthropods)

Subphylum Hexapoda (Hexapods)

Class Insecta (Insects)

Order Hemiptera (True Bugs, Cicadas, Hoppers, Aphids and Allies)

Suborder Heteroptera (True Bugs)

Infraorder Cimicomorpha

Family Reduviidae (Assassin Bugs)

Subfamily Harpactorinae

Tribe Harpactorini

Genus Arilus (Wheel Bugs)

Species cristatus (North American Wheel Bug)

Other Common Names

Wheel Bug (also applies to the rest of the genus)

Explanation of Names

Arilus cristatus (Linnaeus 1763)

cristatus (L) 'crested'

The common name derives from the cog-like projection on the back of the adult

Size

at 28-36 mm (females larger than males), our largest assassin bug(1)

Identification

The "cogwheel" on the adult's back is unmistakable

Range

e NA (ON-FL to IA-KS-NM-CA) to C. Amer. - Map (2)(Hagerty & McPherson 2000)(3)

Habitat

Found where prey is abundant: adults often lurk on composite flowers attractive to insects, or prowl in trees where caterpillars are plentiful

Season

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

Food

All stages prey on other insects (caterpillars, aphids, bees, sawflies, etc.)

Life Cycle

One generation 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 on trees, shrubs or other structures, generally within 4 feet of the ground

Eggs hatch in spring:

Nymphs face predation

and cannibalism

(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

Molting:

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

and leave behind just an empty shell, inverted tracheal tubes and all

Adults are generally not seen until May even in warmest parts of the US and may survive into December

Some are unfortunate victims of parasitoids

despite chemical defenses

Others thrive, sometimes even with deformed wheels

Print References

Hagerty A.M., McPherson J.E. (2000) Life history and laboratory rearing of Arilus cristatus (Heteroptera: Reduviidae) in Southern Illinois. Fla. Entomol. 83: 58-63. (Full text)

Internet References

Featured Creatures (Mead 2014)(4)

Works Cited

1.	How to Know the True Bugs Slater, James A., and Baranowski, Richard M. 1978. Wm. C. Brown Company.

2.	The Reduviidae (Hemiptera: Heteroptera) of Alabama, with a morphological key to species Clem C.S., Swanson D.R., Ray C.H. 2019. Zootaxa 4688: 151–198.

3.	Global Biodiversity Information Facility (GBIF)

4.	University of Florida: Featured Creatures

Contributed by Troy Bartlett on 16 February, 2004 - 12:32pm
Additional contributions by cotinis, Hannah Nendick-Mason, john and jane balaban, Beatriz Moisset, Chuck Entz, Mike Quinn, v belov, PaleoJon
Last updated 23 April, 2023 - 11:19am

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