Are Wheel Bugs Poisonous? Debunking the Myths

Wheel bugs, scientifically known as Arilus cristatus, are large and distinctive-looking insects that can spark curiosity due to their unique appearance.

These insects are known for the cog-like toothed wheel on their thorax, which is exclusive to their species in the United States.

While they may appear intimidating, wheel bugs are beneficial insects that prey on various other arthropods, such as caterpillars and moths, making them a natural form of pest control.

Are Wheel Bugs Poisonous

Despite their usefulness, one concern that may arise is whether or not wheel bugs are poisonous.

Yes, wheel bugs are venomous insects.

Their bite can be painful and cause localized reactions in humans, they are not typically considered dangerous unless someone has an allergic reaction.

Wheel bugs use their piercing-sucking mouthparts to inject venom into their prey, which includes insects like caterpillars, beetles, and other small creatures.

It’s best to avoid handling wheel bugs to prevent accidental bites. Some prominent characteristics of wheel bugs include:

  • Length: 1 to 1-1/2 inches
  • Color: Light gray to grayish-brown
  • Distinct wheel-like structure on their thorax
  • Beneficial insect; preys on other arthropods

Pros of wheel bugs:

  • Natural pest control
  • Preys on harmful insects

Cons of wheel bugs:

  • Painful bite
  • Should be handled with caution

What Are Wheel Bugs

Arilus Cristatus

Wheel bugs, scientifically known as Arilus cristatus, are insects that belong to the assassin bug family.

They are native to the U.S. and play a beneficial role in the environment by preying on pest insects.

  • Found in the U.S.
  • Predators of pest insects

Assassin Bug Family

These insects belong to the Reduviidae family, which consists of various members known as assassin bugs.

The wheel bug is just one of many species in this family that share similar characteristics.

  • Reduviidae: assassin bug family
  • Wheel bug is one species among many

Physical Features

Wheel bugs have unique physical features that make them easily identifiable.

Their most prominent feature is the cog-like toothed ‘wheel’ on their thorax, with 8-12 teeth or tubercles.

They have membranous wings, creating an X pattern on their backs, and strawlike mouthparts for piercing and sucking.

Some distinguishing features include:

  • Cog-like toothed ‘wheel’ on thorax
  • Membranous wings with X pattern
  • Strawlike mouthparts for piercing and sucking

Nymphs of the wheel bug also exhibit similar physical features but have a crest instead of the wheel structure.

They can be easily mistaken for velvet ants, but are actually true bugs belonging to the Hemiptera order and Heteroptera suborder.

Physical Comparison Table

FeatureWheel BugVelvet Ants
Taxonomic GroupHemiptera (True Bugs)Hymenoptera (Wasps)
Crest/WheelWheel structure (adults)N/A
WingsMembranous, X patternSome wingless, others winged
MouthpartsStrawlike for piercing/suckingChewing, only female has sting

The Wheel Bug and Its Prey

Common Prey

The wheel bug, a type of assassin bug, preys on a variety of insects, some of which are considered pests. Here are examples of wheel bug prey:

  • Beetles: including invasive species like the brown marmorated stink bug (Halyomorpha halys)
  • Caterpillars: such as the destructive io moth caterpillars
  • Aphids: small insects that can cause damage to vegetables in the garden
  • Ants: social insects that can become a nuisance in certain environments
  • Wasps: specifically, paper wasps which can be harmful to humans

Predation Behavior

The wheel bug is an effective predator, using its raptorial front legs to capture prey.

Once captured, it injects saliva containing chemicals that paralyze the prey and begin digesting it.

Wheel Bug Predation BehaviorExample PreyDescription
CaptureBeetles, caterpillarsGrasps with enlarged forelegs
InjectAphids, antsInjects paralyzing saliva
DigestWasps, beesFeeds on liquefied prey tissue

Benefits in the Garden

Wheel bugs can provide benefits in a garden setting by controlling pest populations, including:

  • Reducing pest damage: Eliminating insects such as beetles and caterpillars that harm vegetables and other plants
  • Natural control: Serving as a predatory alternative to chemical pesticides
  • Supporting biodiversity: Contributing to a balanced ecosystem by keeping pest populations in check

Are Wheel Bugs Poisonous

Venom and Bite

Wheel bugs (Arilus cristatus) are venomous, not poisonous. They possess a painful bite due to their venomous saliva.

They are a type of assassin bug and use their venom to subdue their prey. The primary features of their bite include:

  • A sharp, needle-like mouthpart called a rostrum
  • Injecting venomous saliva to immobilize prey

Effects on Humans

While wheel bugs are not poisonous to humans, their bites can be quite painful and may cause some discomfort and reactions.

The effects of wheel bug bites on humans include:

  • Pain that may be more severe than a bee sting
  • Redness, swelling, and itching at the bite site
  • Possible allergic reactions for sensitive individuals

Comparing a wheel bug bite to a bee sting and a snakebite:

FeatureWheel Bug BiteBee StingSnakebite
PoisonousNoNoYes (depends on species)

Behavior and Habitat of Wheel Bugs

Geographical Distribution

Wheel bugs are primarily found in the United States, with a wide range extending from Pennsylvania to Florida.

They are known for their beneficial role as predators to pest insects.

For example, gardeners might appreciate their presence for controlling pests in their plants.


Wheel bugs typically inhabit gardens, fields, and forests.

During the winter months, they overwinter by seeking shelter in leaf litter or other hidden spots.

Their unique appearance, such as a cogwheel-like structure on their backs, makes them easily identifiable in their environment.

Key Features of Wheel Bugs:

  • Large forelegs for grasping prey
  • Cogwheel-like structure on their back
  • Predatory behavior towards pest insects

Characteristics of Wheel Bugs:

  • Size: Up to 1 3/8 inches long
  • Color: Brown to gray
  • Geographical range: United States (from Pennsylvania to Florida)
FeatureWheel BugBee Sting
Bite SeverityMore intenseLess intense
PoisonousNoNo (for humans)
Beneficial rolePest controlPollination

In conclusion wheel bugs play a vital role in controlling pest populations and can be a useful ally for gardeners across their geographical range.

Other Dangerous Insects

Insect Comparison

When considering the dangers of insects, wheel bugs are not the only species to worry about.

There are many other insects and arachnids that pose potential hazards to humans.

Here is a brief overview of some notable dangerous insects and their characteristics:

Immature, female Northern Black Widow

Black Widow Spiders:

  • Latrodectus sp.
  • Bites can cause muscle spasms, abdominal pain, and difficulty breathing
  • Possess a lethal venom

Brown Recluse Spiders:

  • Loxosceles sp.
  • Bites can result in serious skin reactions and necrosis

Red Widow Spider:

  • Latrodectus bishopi

Africanized Honey Bee (Killer Bee):

  • Apis mellifera scutellata
  • Aggressive, more likely to sting humans
  • Increased risk of allergic reactions due to multiple stings

Arizona Bark Scorpion:

  • Centruroides exilicauda
  • Stings can cause pain, numbness, and tingling

Red Harvester Ants:

  • Pogonomyrmex barbatus
  • Stings are painful and result in swelling

Striped Bark Scorpions:

  • Centruroides vittatus


  • Various species
  • Possess urticating hairs that can cause irritation
SpeciesDistinguishing FeaturesRisks and Danger
Black WidowRed hourglass on abdomenLethal venom
Brown RecluseDark brown, violin-patternNecrosis
Red WidowRed legs, black abdomenPainful bites
Africanized Honey BeeBee with aggressive behaviorMultiple stings
Arizona Bark ScorpionSmall, pale yellow scorpionPainful stings

Additionally, some pests can cause harm indirectly, like rats and moths that can be a nuisance to crops and vegetable gardens.

For instance, the Oriental rat flea is known for spreading the bubonic plague.

To protect our health and property, it is crucial to be knowledgeable about these dangerous insects and their possible threats.


To wrap it up, delving into the world of wheel bugs shows they’re indeed venomous.

Their bites can be painful for us, but usually not a big danger unless someone’s allergic.

Understanding their role in nature helps us see how they fit in.

For safety, it’s best to watch them from a distance and let them do their thing without bothering them.

Reader Emails

Over the years, our website, has received hundreds of letters and some interesting images asking us about wheel bugs. Scroll down to have a look at some of them.

Letter 1 – Wheel Bug

This bug is strange, what is it, please?
Location: West-Central Florida.
June 2, 2011 3:46 pm
Hello bugman,
I was watering my plants and I saw whis WEIRD looking bug and I ran in the house to get my camera before it flew off. It was still there when I came back and noticed a bit more that it was at his/her home.

The plant it is in, is a lilly of some sort and he/she has a home inside, with a bit of spider web around it…which I don’t know if it is it’s web….since it doesn’t have 8 legs like a spider.

Me and husband are guessing it might be in a locust family. It looks like it has a very small head. I think it is an alien! LOL!
The location is West-central Florida, woodlands. The season is close to the end of spring.
Signature: is this an alien bug?

Wheel Bug

This is not an alien bug, but a native predatory species called a Wheel Bug.  We have much information about Wheel Bugs in our archives. 

Wheel Bugs will help keep your garden free of insects that will damage your plants, and Wheel Bugs should be handled with caution.  They are capable of biting if they are not handled with caution.

Letter 2 – Wheel Bug

cool looking bug I found on my satellite dish
Location: Charlottesville, VA
July 10, 2011 8:17 pm
Hi! I was up on my roof yesterday and saw this really interesting bug with a shiny patch of dark grey material on its back, and a spiked spine.

Also had an interseting hooked beak with a small worm in it. Can you identify it? Thanks!
Signature: James in VA

Wheel Bug

Hi James,
This is a Wheel Bug, one of the predatory Assassin Bugs in the family Reduviidae, and its largest North American member.  They use the beaklike mouth to pierce the prey and suck fluids. 

They are also capable of biting humans, though not aggressively.  Bites occur when they are accidentally encountered or carelessly handled.

Letter 3 – Wheel Bug

Subject: this insects’ got back
Location: Dallas (East), Texas
June 26, 2012 8:13 am
Went for a late evening drive to get a cheeseburger with the windows down at the drive-in Dairyette (worth a trip to Dallas). When I got home and let the dog out there it was, right where you would reach to get the seatbelt on the passenger side.

I moved it and took a few pictures. There is an amazing iridescent gold shield on its lower back and a daunting spiked ridge behind its neck. What species and is it male?
Signature: Dave

Wheel Bug

Hi Dave,
Though there is no dearth to the postings on our site devoted to the Wheel Bug (it is one of our Top 10 identification requests) we have decided to post your letter for two reasons.  First and foremost, we found your email totally entertaining and informative. 

Second, we don’t get many adult Wheel Bug photos this early in the season.  Most recent examples have been immature nymphs that lack wings and the signature coglike “wheel” on the thorax.  Male and female Wheel Bugs look alike, though females are generally larger. 

You should exercise caution when handling a Wheel Bug.  Though they are not aggressive towards humans, they are predators and they possess a piercing beak of a proboscis.  The bite is reported to be quite painful, though not dangerous.

Letter 4 – Wheel Bug

Wheel bug found
Hi bugman,
Just wanted to let you know that I found this cool little bug in the flowers around my pond. Didn’t know what it was but came on your site and found it within a matter of minutes. Great site. I found this in Northeast PA.
Catasauqua, PA

Hi E K,
It always makes us so happy when people use the site as a research tool instead of just firing off a letter with an out of focus photo before even looking at any of the possibilities we have to offer. your image is great and we are happy to have it.

Letter 5 – Wheel Bug

What’s this one?I have searched your site and have not found anything quite like this one. Can you help me identify it? I live in Charlotte, NC .

We suspect you only searched our homepage. If you go to the Assasin Bug page, you will find many pictures of Wheel Bugs, but nothing as glorious as yours.

The Wheel Bug, Arilus cristatus, is valuable in the garden for the many pests it devours. Watch out though, it will give a painful bite if not respected.

Letter 6 – Wheel Bug

I saw this bug
Hi there, I am originally from Argentina but I live in Texas now. Today I found this bug that in Argentina we call “vinchuca” and transmit a disease called “chagas” is a very bad disease.

Someone told me that is a inoffensive beetle but it looks like the vinchuca (or kissing bug). The picture is not very good because I was scared. Can you tell me what it is?
Thank you

Hi Adriana,
We also have a Kissing Bug that transmits Chagas Disease, but your photo looks like a Wheel Bug, one of the Assassin Bugs. It is difficult to be certain based on your photo, but the distinguishing feature is the coglike “wheel” on the thorax.

Wheel Bugs are related to Kissing Bugs, and both are true bugs, or Hemipterans. Wheel Bugs are not known to be disease vectors, but they can bite painfully if mishandled. They are beneficial since they destroy many garden pests.

Letter 7 – Wheel Bug

Loud Flyer
Hello Bugman!
I was in Eastern PA this weekend on top of a mountain in Kempton, PA. While admiring the sites, this loud buzzing went very slowly past my ear. When I looked, there was this bug about an inch or so flying by. Its abdomen hung while it flew but managed to land on the side of a tree near me.

I was able to get this photo before it continued on its way. Note that the ridge on its back does run from head to tail and not side to side.. Any help in identifying is appreciated!

Hi Jim,
Great photo of a Wheel Bug, Arilus cristatus, a member of the Assasin Bug Family Reduviidae. These large true bugs can be recognized by the cog like wheel on their backs.

They are friends of gardeners since they eagerly feed on many garden pests, like the caterpillar you put in the jar. Those sucking mouthparts can deliver a painful bite if the bug is carelessly handled.

Incredible website… Now knowing it was an assassin bug, I looked through the assassin bug section of your site to get more information. What a remarkable species! Thank you so much for the work you do!

Letter 8 – Wheel Bug

Close Encounter of the bug kind!
Location: Carroll County, Maryland
October 25, 2010 7:38 pm
Hi there, I had a close encounter with this bug today (He decided to hitch a ride on my jacket!) I screamed at it, I flinged it off my jacket, but I did not resort to creating carnage despite passerby suggestions… any idea what it is? It has to be one of the largest bugs I’ve ever seen – I’d estimate about two inches long or so.
(Sorry about the picture quality, best I could manage with my phone.)
Signature: Angela in Maryland

Wheel Bug

Hi Angela,
We have gotten numerous images of Wheel Bugs in the past week, but we have not posted any of them after supplying a brief answer regarding the bug’s identity. 

Since there have been so many sightings recently, we have decided to post your letter (with its subject line that caught our attention) and your photo even though your photo does not adequately illustrate the coglike crest on the thorax that gives North America’s largest Assassin Bug its common name.

Letter 9 – Wheel Bug

unknown bug
Location: Oklahoma City
October 30, 2010 2:56 pm
I’ve heard it’s a Japanese Suicide Bug & a Wheel Bug. I’d love to know what it is.
Signature: @ScottMo

Wheel Bug

Dear ScottMo,
Wheel Bug is the approved common name for North America’s largest Assassin Bug, but we are quite intrigued with the name Japanese Suicide Bug.  The Wheel Bug will be our featured Bug of the Month for November.

Letter 10 – Wheel Bug

Unknown Insect
Location: San Antonio, TX, United States
December 12, 2010 2:24 am
Hi. I found this insect near a wooded area where I work. It was dead when I found it, unfortunately. Extremely coincidentally, my wife also found one in our own backyard the other day!

I have never seen insects like these, and I thought how rare it could be for me to find 2. Any help identifying what type of insect it is would be most appreciated. I tried researching on my own and only came up with it has a head/snout similar to a weevil. Thanks in advance.
Signature: John C

Wheel Bug

Hi John,
This is a Wheel Bug and it is the largest Assassin Bug in North America.

Thank you very much for that incredibly quick response! Having the name was the key that I needed to unlock all the information about this insect, because before, I was searching for it based on its description.

I just read the whole Wikipedia page on it and some info on other sites. I wonder if I’ll ever see one alive in the wild? The info did mention that it is shy (yet vicious, an odd combo). Anyway, thanks again for the help!

Thanks again. P.S. Do you have any suggestions for containment of my two specimens? I know people put dead butterflies on pins, but I’d rather not impale them (for fear of them breaking).

I was thinking of getting a cheap small clear plastic box or something, maybe Hobby Lobby would have it, to display them (yes, might be weird, but I’m just so fascinated by this insect as neither my wife nor I or any of my family have EVER seen a creature such as this). My wife suggested a container with alcohol. Any ideas?

Hi again John,
We would not recommend putting a pin through an already dried insect.  Many hobby shops have display cases that contain a cottony substance. 

Alcohol is not used for hard bodied insect preservation.  They will last for many years provided they are kept safe from Dermestids and other creatures that damage museum collections.

Excellent! Thank you very much for your help. I’ll be sure to use again if ever I come across an unidentified insect. Thanks again.

Letter 11 – Wheel Bug

Summer 2010
Location: 19347
March 18, 2011 9:00 pm
I took half a dozen photos of this guy in Chester County, PA last summer (2010); he looked silvery sitting in full sun on a silver trash can full of birdseed.
Signature: Sue

Wheel Bug

Hi Sue,
Your Wheel Bug is an impressive creature, the largest Assassin Bug in North America.

Wow, maybe this is why I didn’t see any Japanese beetles this
year.  Thanks!  I’m looking forward to reading your book. 🙂 Sue

Hi again Sue,
If you normally get Japanese Beetles, and you saw none in 2010, you are one lucky gardener.  We have images in our Food Chain section of Wheel Bugs feeding on Japanese Beetles, but one lone Wheel Bug could probably not handle the hoards of Japanese Beetles that typically defoliate a wide variety of plants cultivated in the garden. 

Had you seen an army of Wheel Bugs, that would be a different story.  There may be other predators, like insectivorous birds, that are contributing to the gardener’s war against Japanese Beetles.  We hope you find the book The Curious World of Bugs as entertaining as Daniel intended it to be.

Letter 12 – Wheel Bug

Halloween Insect (some sort of mantis?)
Location: Southeastern Pennsylvania
August 24, 2011 6:32 pm
My father found this insect outside a Halloween store here in Pennsylvania about 7 years ago (October 18, 2004, to be exact).

A Halloween store seemed like an appropriate place to find such a weird-looking insect! I’ve never seen another one like it. We’ve always wondered what it is.
Signature: RickMK

Wheel Bug

Dear Rick
After seven years, you can stop losing any sleep.  This is a Wheel Bug.

Letter 13 – Wheel Bug

What’s that bug?
Location: Indiana, USA
October 6, 2011 4:53 pm
I saw this bug today when I was getting ready to leave my apartment. It was about 2 inches long and at first I thought it was a spider!

When I first found this site, I thought it might be a Western Conifer Seed Bug, but it has a prickly spine along it’s back and the Western doesn’t. Really curious about this bug, I’ve never seen anything like it before!
Signature: Drensik

Wheel Bug

Dear Drensik,
Though they are both in the same insect order, the Western Conifer Seed Bug is a plant feeding Leaf Footed Bug while your Wheel Bug is a predatory Assassin Bug.  Wheel Bugs move slowly, and they will not attach people, however, they can deliver a painful bite if threatened or carelessly handled.

Letter 14 – Wheel Bug

Location: North-east PA
October 10, 2011 11:08 pm
Monday, October 10th, 2011. Sunbury, PA, 6:30pm, Practice Field.
Fortunately our girls are made of sterner stuff because even I was a bit weirded out by this alien looking bug. He/she was rather large, bug-wise, about 1 1/2-2 inches long (not counting his/her veeerrry long legs).

Its’ head was disproportionately small and narrow compared to its’ body. Hopefully the pics are clear enough to see what I mean. I thought maybe it was some kind of nectar bug until I saw some of the pics you have of hunter-types.

It has a very long spear-looking ”tongue” but I couldn’t get a clear enough shot to see if it had pincers, too. It had wings but didn’t seem to care to fly, even when I coaxed it onto a pencil to move elsewhere. What on Earth is it?? I can’t find anything listed even with the odd ”razor-ridge” along its’ back.
Signature: Hannah Lewis

Wheel Bug

Hi Hannah,
The cheerleaders were wise to not try to pick up this Wheel Bug, because though they are not aggressive, they are predatory Assassin Bugs and they might bite if carelessly handled.

Letter 15 – Wheel Bug

need bug ID-ed
Location: Columbus, OH
October 26, 2011 10:06 pm
What is this bug??? It moved like a stink bug (I have gotten very familiar with stink/squash bugs this year). I found this on a grave monument in Columbus, OH. Fascinated by its crazy spiked mohawk thing.
Signature: ohiodave

Wheel Bug

Hi ohiodave,
This amazing creature is called a Wheel Bug and your observations about it looking like a stink bug is justifiable since they belong to the same insect order Hemiptera.  Wheel Bugs are predatory Assassin Bugs. 

In the past two weeks, we have received numerous identification requests for Wheel Bugs from many parts of Eastern North America.

Letter 16 – Wheel Bug

Big brown spooky looking bug with spiked midsection
Location: Maryland
November 15, 2011 6:35 pm
Hello. We found this 2 inch brown and black bug on our deck in Maryland. He appears to have wings, but will not fly. He has two reddish antennae, a ridge on his mid section, and what looks like a proboscis. What is it! Thank you!
Signature: The Karas family

Wheel Bug

Dear Karas Family,
Your description of a Wheel Bug is spot on.

Letter 17 – Wheel Bug

The Kaiser’s Bug
Location: 38.552246,-77.926088
November 16, 2011 9:00 am
Dear Sir,
My wife and I are purchasing a new home in Brandy Station, Virginia. During the home inspection, I noticed this critter crawling up the siding, and was blown away. I’ve never seen anything like it. I thought the ridge on its back looked like an old German helmet, so I’m calling it a Kaiser Bug for now.
Signature: -Will K.

Wheel Bug

Hi Will,
While Kaiser’s Bug is a nice name, the Wheel Bug did receive its name from the coglike ridge on its back.

Letter 18 – Wheel Bug

Subject: can you help me identify
Location: Berkeley Springs, WV
October 16, 2012 8:15 pm
Hi I live in WV and found this guy hanging out on my back porch he was there all day, and i can honestly say that none of my family or friends or myself have ever seen one. If yyou could help me out with some info on this guy i would appreciate it. Thanks
Signature: Ian Lawyer

Wheel Bug

Dear Ian,
Though we try to make several new postings daily, we only post a fraction of the identification requests we receive.  We are unable to even respond to many of the requests we receive, though we try our best. 

Many submissions just get a quick ID without becoming a posting, and we have identified numerous unposted Wheel Bugs, Arilus cristatus, in the past few weeks.  Your photo is quite exceptional, so we decided to post your letter.  Wheel Bugs are the largest Assassin Bugs in North America. 

Though Wheel Bugs move in a docile manner, they should be handled with caution since many Assassin Bugs will bite if provoked and the bite can be quite painful.  Wheel Bugs use their piercing mouthparts to jab their prey and they suck out the fluids for nourishment. 

They are quite capable of piercing human skin, however they are not aggressive towards humans.  The unique coglike “wheel” on the thorax is structurally unique among North American Assassin Bugs and it probably serves to make them difficult to swallow by birds or other insectivores.

Letter 19 – Wheel Bug

Subject: Large with serrations on back has wings
Location: Near Pittsburgh, PA
October 25, 2012 9:16 am
Hello, This bug was found 10/24/12 near Pittsburgh, PA (in the country)on my Mother’s deck. What is it? Is it dangerous? Have never seen anything like it before.
Signature: Laura

Wheel Bug

Hi Laura,
We have been getting several requests each day recently to identify Wheel Bugs like yours.  With winter approaching, Wheel Bugs,
 Arilus cristatus, have matured and they are attracting more attention.  Wheel Bugs are stealth predators that should be handled with caution. 

Though they are not aggressive, they are capable of delivering a painful bite with their proboscis that is designed for piercing prey and sucking fluids from the bodies of other insects.  A recent request called it a Stegosaurus Bug.  Your excellent photograph nicely focuses on the coglike crest that gives the Wheel Bug its common name.

Hi Daniel,
Thank you for the explanation. Have these insects always been found in the Northeast? I have never seen one before. Should we be concerned that where there’s one there’s more? 

And, when do they lay eggs and where? We thought maybe the one we found was sick because it only moved a few inches in 2 days. We have a lot of stink bugs this fall so maybe that’s what attracted it?
All the best,

Hi Laura,
The Wheel Bug is the largest Assassin Bug in North America and they are found in the Northeast.  The female lays eggs in the fall, often on a branch or wood siding.  The eggs overwinter and hatch in the spring.  The hatchling Wheel Bugs are often mistaken for ants or spiders.

Letter 20 – Wheel Bug

Subject: Wheelbug in Rockwall tx
Location: Rockwall tx
November 6, 2012 5:47 pm
I also live in Rockwall Texas and just discovered a wheel bug in my back yard. I have never seen one before are they native to this area and why all of a sudden are they beginning to appear? Thanks.
Signature: Gary in Texas

Wheel Bug

Hi Gary,
The typical range of the Wheel Bug includes Texas.  Most Wheel Bugs reach adult size in the autumn and they become more visible.  Smaller nymphs often pass unnoticed earlier in the year.  Additionally adults have wings and they are more mobile which allows them to search for mates.

Letter 21 – Wheel Bug

Subject: Beautiful 4 inch bug
Location: Tampa Florida
February 21, 2013 6:50 pm
Another strange visitor in our yard here in Tampa Florida. V shaped body.
Signature: LSolie

Wheel Bug
Wheel Bug

Dear LSolie,
This is a Wheel Bug and four inches seems rather huge.  We would suspect two inches to be the maximum size they attain.

Letter 22 – Wheel Bug

Subject: Crazy looking bug
Location: Wake county, NC
June 14, 2013 2:05 pm
This bug was on my deck in summer time, near Raleigh, NC. What in the world is he? Thanks!
Signature: Traci – NC

Wheel Bug
Wheel Bug

Hi Traci,
We love your photo of a Wheel Bug in a clothespin.

Letter 23 – Wheel Bug

Subject: Armored bug?
Location: Amelia, Ohio
July 25, 2013 8:43 pm
A friend of mine found this at her place in Ohio tonight. It’s not the best of pictures, but do you have any idea what this might be? I believe it is approximately 1 1/2”-2” in length.
Signature: Becky

Wheel Bug
Wheel Bug

Hi Becky,
This is a predatory species of Assassin Bug known as a Wheel Bug.  Wheel Bugs are not aggressive, but they should be handled with caution as they might deliver a painful bite.  We probably have close to 100 postings of Wheel Bugs on our site.

Letter 24 – Wheel Bug

Subject: Interesting bug??
Location: Western Pennsylvania
September 11, 2013 4:52 pm
Bugman, I am a commercial roofer and we have recently come across an insect on two different jobs/ locations that we are unfamiliar with. Hope you can help us out. Thanks.
Signature: Michael Miano

Wheel Bug
Wheel Bug

Hi Michael,
This Assassin Bug is commonly called a Wheel Bug because of the coglike appearance of its thorax.  Wheel Bugs, like other Assassin Bugs, will deliver a painful bite if carelessly handled.

Letter 25 – Wheel Bug

Subject: No idea what Satan-spawn this is
Location: Carrick, Pittsburgh, Pennsylvania
October 7, 2013 2:45 pm
Signature: Brandon

Wheel Bug
Wheel Bug

Hi Brandon,
That is a bit harsh.  This is a Wheel Bug, the largest North American Assassin Bug and it is an impressive predator.  Handle with caution.  they are known to bite.  The bite is painful, but not considered dangerous.

Letter 26 – Wheel Bug

Subject: Black flying bug with spikes
Location: Gallipolis ohio
October 14, 2013 10:07 pm
Just wondering what this bug is
Signature: Lacey

Wheel Bug
Wheel Bug

Hi Lacey,
This Wheel Bug is the largest North American Assassin Bug.  Your photo makes it look larger than a human hand.  We wish the photo was more in focus as that would really add to the scale illusion.

Letter 27 – Wheel Bug

Subject: What kind of bug is this?
Location: Salisbury,md
October 15, 2013 1:11 pm
Found this bug outside my work place and we don’t know what it is. Never have anyone of us ever seen this bug before.
Signature: Angela Bounds

Wheel Bug
Wheel Bug

Dear Angela,
This is a beneficial, predatory Wheel Bug.  They move slowly and they are not aggressive towards humans, however, you want to stay clear of the piercing mouth that is evident in your photo.  Wheel Bugs can deliver a painful bite if carelessly handled.

Letter 28 – Wheel Bug

Subject: What is this bug?
Location: Delaware State
October 18, 2013 8:47 pm
Dear Bugman,
Could you help me find the name of this bug we found in a park yesterday.
Thank you very much.
Signature: Emma

Wheel Bug
Wheel Bug

Hi Emma,
This is a Wheel Bug, the largest Assassin Bug in North America.  While Wheel Bugs are not aggressive toward humans, they should be handled with caution as they are capable of inflicting a painful bite. 

We have been receiving many more Wheel Bug identification requests than usual this season, which causes us to suspect that they are more numerous than usual.

Thank you very much for taking the time!

Letter 29 – Wheel Bug

Subject: What is it?
Location: West Central Ohio
October 18, 2013 5:13 pm
A friend in wsest Centeral Ohio shot this photo today Oct. 18, 2013. Can you tell me what it is?
Signature: Tammy Hiday

Wheel Bug
Wheel Bug

Hi Tammy,
This is a Wheel Bug, and we have gotten countless identification requests for Wheel Bugs this fall.  Your letter will post live to our site in early November when we are out of the office visiting family in Ohio.

Letter 30 – Wheel Bug

Subject: What’s that bug?
Location: South eastern new jersey
November 11, 2013 11:54 am
South eastern new jersey. By wetlands. Mid November. This thing is 2 inches or more! I found it on my deck. It looks like there’s a hook coming from it’s face. Yikes! I’m not usually afraid of bugs but this one gives me the willies!
Thanks in advance!
Signature: sunny

Wheel Bug
Wheel Bug

Hi Sunny,
This is a predatory Wheel Bug, the largest North American Assassin Bug.  Like other members of its family, the Wheel Bug has a mouth adapted to piercing the skin and sucking fluids from its prey. 

Assassin Bugs will bite humans if carelessly handled, but except for the Blood Sucking Conenose Bugs or Kissing Bugs, Assassin Bugs are considered harmless to humans.

Letter 31 – Wheel Bug

Subject: Cool bug, no clue what it is!
Location: Virginia
December 9, 2013 3:57 am
Hey Mr. Bug man!
I teach third grade science in rural southeastern VA. One day we were coming in from the playground and saw this cool little thing on the brick building.

The ground was pretty wet that day, and it was chilly if I remember correctly. My students were wondering what this critter might be. We left it alone, but I haven’t seen it again.
Signature: Stumped

Wheel Bug
Wheel Bug

Dear Stumped,
Your students encountered a Wheel Bug, the largest North American Assassin Bug.  This is a beneficial hunter, but they have mouths designed for piercing the exoskeleton and sucking the nutrients from prey, and they can deliver a painful bite if carelessly handled.

Letter 32 – Wheel Bug

Subject: Odd bug
Location: Northwest Ohio
December 28, 2013 8:18 pm
Dear Bug man,
This picture was taken by myself in Northwest Ohio. It was in the late summer of 2013. I have never seen a bug such as this one. It was crawling up the screen door on the front porch.
Signature: Tri-Ana

Wheel Bug
Wheel Bug

Dear Tri-Ana,
We get numerous requests to identify Wheel Bugs like your individual because of their unusual, almost prehistoric appearance.  Wheel Bugs are predators and they are the largest members of the Assassin Bug family, Reduviidae, that are found in North America. 

Letter 33 – Wheel Bug

Subject: Kissing Bug?
Location: Cabot, AR
August 16, 2014 8:13 am
Found this bug on my patio. We live in a state where the “kissing bug” is making the news. I have gotten several conflicting answers and photos on Google are making me even more confused. I just want to know for sure what it is!
Signature: Don’t kiss me!

Wheel Bug
Wheel Bug

Dear Don’t kiss me!,
Your confusion is understandable because this predatory Wheel Bug is in the same family, the Assassin Bug family Reduviidae, as the Kissing BugWheel Bugs prey upon other insects and they feed using their sharp proboscis that they use to pierce the prey and then suck the fluids from the body. 

Kissing Bugs in the genus Triatoma feed in a similar manner, but they feed on the blood of birds and mammals, including sleeping humans.  The problem with Kissing Bugs is that they can spread Chagras Disease when they bite. 

Though there is a chance that carelessly handling a Wheel Bug will result in a painful bite, there is no negative, lasting health problem associated with the bite, merely local swelling and tenderness.

Letter 34 – Wheel Bug

Subject: Weird scary bug
Location: Suburb of Philadelphia
September 2, 2014 3:33 pm
Dear Bugman, my name is MK. My husband found this bug last night, 09/01/14, in the evening. It had a very long stinger on the front and kept trying to snack at my husband. We found it in the garage. We Live in a suburb of Philadelphia. Any information would be great, thanks.
Signature: MK

Wheel Bug
Wheel Bug

Dear MK,
This is a predatory Wheel Bug, and though they are not aggressive, they can bite if provoked.

Letter 35 – Wheel Bug

Wheel Bug
Wheel Bug

Subject: Identify bug
Location: West Tennessee
October 11, 2014 7:55 pm
In the yard. Don’t know what it is.
Signature: Mike

Hi Mike,
Because of its highly distinctive outline, including the coglike projection on the thorax, it is unlikely that an adult Wheel Bug will be confused with any other North American insect. 

Wheel Bugs are in the predatory Assassin Bug family and they should be handled with caution since a painful bite might result from careless handling.

Letter 36 – Wheel Bug

Subject: What’s this bug
Location: Charlottesville, Virginia
October 20, 2014 11:16 am
Hi, I found this bizarre looking guy dying on my back steps yesterday. His body is about 2 inches long. I live in a rural, open area. I think he is the stink bug king, because he was hanging out with a lot of dying stink bugs. Thanks for your help!
Signature: Melissa

Wheel Bug
Wheel Bug

Dear Melissa,
We would love to learn that the Wheel Bug in your image is feeding on invasive Brown Marmorated Stink Bugs, but we don’t think that the native predators could ever eliminate the impact of the rapidly spreading import from Asia.

Letter 37 – Wheel Bug

Subject: what kind of bug is this?
Location: Boonsboro Maryland
October 25, 2014 6:05 pm
I’m just wondering what kind of bug this is and if you can help that would be wonderful thank you.
Signature: Kyle Kwiatkowski

Wheel Bug
Wheel Bug

Dear Kyle,
Wheel Bugs like your individual attract attention throughout their lives, from young hatchlings, to brightly colored nymphs, to transitionary molts, to mating adults.

Letter 38 – Wheel Bug

Subject: What is this bug?
Location: Ohio
November 3, 2014 11:14 pm
Yesterday, November 3rd on a sunny day around 54 degrees in Englewood Ohio, we saw this large flying bug crawling up the side of my parents shed. Never seen one like it before.
Signature: Scott Stewart

Wheel Bug
Wheel Bug

Hi Scott,
This is a predatory, beneficial Wheel Bug.  They mature in the autumn and they often attract attention as they are the largest Assassin Bugs in North America.

Letter 39 – Wheel Bug

Location: Southern New Jersey
November 11, 2014 3:41 pm
Found this big guy out back of my office hanging out on the stucco in the sun. He moves very slow. His head seems to be the little stem that hangs far out in front of the rest of him.

Just behind the head is what seems like a spiky back-pack. There’s a single line of spikes running down the middle of this ‘back-pack’. His abdomen was covered by wings.

Both pictures were taken about a month apart at the same location. The one looking head-on was taken today (11/11/14).
Whats this bug?!
Signature: Adam

Wheel Bug
Wheel Bug

Dear Adam,
This Wheel Bug is an Assassin Bug in the family Reduviidae, not a Beetle.  The Wheel Bug is a predator, and though it is not aggressive toward humans, it might bite if carelessly handled, and we suspect the bite is painful.

Letter 40 – Wheel Bug

Subject: Stegosaurus?
Location: Eastern virginia, USA
November 14, 2014 8:17 pm
Found this beauty in my backyard in eastern Virginia in early November. I’ve never seen such a bug, was larger than a nickel but smaller than a quarter. What is it?
Signature: Tom

Wheel Bug
Wheel Bug

Hi Tom,
It seems like each autumn we get at least a few requests to identify a dinosaur bug or stegosaurus bug, because that is the time that Wheel Bugs like your individual attain maturity and develop the coglike thoracic feature.

Letter 41 – Wheel Bug

Subject: Scorpian like bug
Location: South Carolina
July 5, 2015 8:01 am
Could you help id this bug. Much like a grasshopper but has a scorpian like tail. Throws the tail over the back when mad. They are all over the stable which houses racehorses.
Signature: Catherine French

Wheel Bug
Wheel Bug

Dear Catherine,
This is a beneficial, predatory Wheel Bug that feeds on other insects.  It will not harm your horses, though we are very curious why there are large numbers of them near the stables.  Perhaps they are feeding on flies.

Thank you so much for answering my question. There are a lot of flies around the barns so they must love the atmosphere. Thanks again. Catherine

Letter 42 – Wheel Bug

Subject: Creepy Porch Friend
Location: Eastern Shore/Ocean City, Maryland
July 28, 2015 7:18 am
Hi, in the previous 24-hour period, I have found 3 of these creepy crawlers. One in the garage and two on the front porch. It is about 1.5″ – 2″ long. It’s gray in color.

If another photo is needed, I can take another photo. It seems like a cross between a stink bug and a spider (6 legs though).
Signature: Rena

Wheel Bug
Wheel Bug

Dear Rena,
Your image of a Wheel Bug is shot from an atypical perspective.  Most people take images from the side in order to feature the coglike projection or “wheel” on the thorax and many people describe the Wheel Bug as prehistoric and some have even coined the name Stegosaurus Bug

The Wheel Bug is a beneficial predator, but they should be handled with caution as a painful bite might result.

Hi Daniel,
Thank you for the timely response and identification. I have pest control service coming out. If there was only one around,

I wouldn’t have called but after finding three, I was afraid they could cause damage (of course not knowing what it was when I called). As a beneficial predator, what do they prey on?
Thank you,

Hi Rena,
They will prey on many species of insects.  We already provided a link to a Wheel Bug feeding on an invasive, exotic Japanese Beetle.


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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25 thoughts on “Are Wheel Bugs Poisonous? Debunking the Myths”

  1. These things seem to be out in mass here in western NC this year. I still am amazed at their appearance. One question though, has anyone else noticed they produce a red/pink liquid from the back? My friend had one on him and he is afraid of bugs so I took it off of him and the bug produced a red/pink liquid. I was thinking its a bad tasting substance to deter predators?

  2. i also found this prehistoric looking bug on my door step. my bug also has a red thingy hanging of his hind side. i was told anything with red like that it is poisonous. true or not i don’t know? that’s why i came in here to check it out. back in the end of june 2011 in columbus ohio. i had been playing with him to make him react and he/she really wasn’t interested or bothered by my playfulness. i had posted “what’s this bug” back in june of this year (2012). and received no replies. tonight i was just checking on my bug and found if not the same or very similar to it from u dave. i will post my bug again so that all can see. mine has a real pretty copper hinny area.

    • Thanks for your comment. For the record, our tiny staff often takes a holiday in June and while we are away from the office, mail frequently piles up unanswered. We try to respond to as many requests as possible, but we only have the capabilities to respond to a fraction of the requests we receive, and an even smaller percentage get posted live to the website. We are happy you were able to self identify your Wheel Bug. They are capable of biting, but we do not get as many reports of bites from Wheel Bugs as we do from other Assassin Bugs.

  3. Adriana, I found one last summer outside, and it looked like the Vinchuca to me, (I lived in Bolvia once). I live in the Texas Rio Grande Valley, and I did here on the news last summer that there were some found here. Make sure they don’t bite you on the lip, as you know about Chagas disease.

  4. I believe one of these bugs was on my deck yesterday. It freaked me out bad. We likened it to a very large stink bug but worse. It did not move fast but we did not appreciate it being around.

  5. I found one last year that had a Japanese beetle in its clutches, so I was curious what it was. Now I see the wheel bug nymphs all over the place and I know to leave them alone.

  6. I saw one on my house the other day. I thought it was a queen stink bug! The a friend said she saw one at work. Glad w didn’t touch it!

    Glen Burnie, Md

  7. Found a wheel bug in Manassas, VA – I’ve lived in Northern Virginia all my life and have never seen a bug like this. Quite interesting!

  8. I didn’t see a single Wheel Bug this year, or any Preying Mantis. There were a lot less Japanese Beetles as well, I think there’s a connection.

  9. Yep my 4yr old son was stung by one of these wheel bugs today in Japan. I thought it was totally harmless and didn’t bother taking it of him, then shortly after he gave a yelp and his eyes started to well up… i picked up the bug for closer inspection and saw the hooked spike for a mouth. It may not have been all that lively due to the cold but it sloooowly tried to extent its spiked snorkle mouth thingy again to sting me. Got rid of it but good to know its a beneficial predetor bug for next time.

  10. I have been seeing these bugs in my area recently.

    I witnessed one of these bugs feeding on a late stage nymph of the spotted lanternfly approximately two months ago in my back yard in Shartlesville, PA.

  11. I live about 20 miles from St. Louis, Mo. Had a wheel bug on my porch! First time to see or notice one. I’ve lived here about 10 years.


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