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.
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
| Feature | Wheel Bug | Velvet Ants |
|---|---|---|
| Taxonomic Group | Hemiptera (True Bugs) | Hymenoptera (Wasps) |
| Crest/Wheel | Wheel structure (adults) | N/A |
| Wings | Membranous, X pattern | Some wingless, others winged |
| Mouthparts | Strawlike for piercing/sucking | Chewing, 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 Behavior | Example Prey | Description |
|---|---|---|
| Capture | Beetles, caterpillars | Grasps with enlarged forelegs |
| Inject | Aphids, ants | Injects paralyzing saliva |
| Digest | Wasps, bees | Feeds 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:
| Feature | Wheel Bug Bite | Bee Sting | Snakebite |
|---|---|---|---|
| Painful | Yes | Yes | Yes |
| Venomous | Yes | Yes | Yes |
| Poisonous | No | No | Yes (depends on species) |
| Redness/Swelling | Yes | Yes | Yes |
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.
Habitat
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)
| Feature | Wheel Bug | Bee Sting |
|---|---|---|
| Bite Severity | More intense | Less intense |
| Poisonous | No | No (for humans) |
| Beneficial role | Pest control | Pollination |
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:
- Latrodectus sp.
- Bites can cause muscle spasms, abdominal pain, and difficulty breathing
- Possess a lethal venom
- Loxosceles sp.
- Bites can result in serious skin reactions and necrosis
- 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
- Centruroides exilicauda
- Stings can cause pain, numbness, and tingling
- Pogonomyrmex barbatus
- Stings are painful and result in swelling
- Centruroides vittatus
- Various species
- Possess urticating hairs that can cause irritation
| Species | Distinguishing Features | Risks and Danger |
|---|---|---|
| Black Widow | Red hourglass on abdomen | Lethal venom |
| Brown Recluse | Dark brown, violin-pattern | Necrosis |
| Red Widow | Red legs, black abdomen | Painful bites |
| Africanized Honey Bee | Bee with aggressive behavior | Multiple stings |
| Arizona Bark Scorpion | Small, pale yellow scorpion | Painful 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.
Conclusion
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.
25 Comments. Leave new
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?
We are not certain of the exact nature of the excretion.
I’ve actually seen one fly. I thought it was an enormous beetle, so I followed it to a nearby tree and realized it was a wheelbug. Very cool thing to see.
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.
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.
Wheel Bugs do not carry Chagas Disease. Blood Sucking Conenose Bugs or Kissing Bugs in the genus Triatoma (see BugGuide at http://bugguide.net/node/view/4789) are vectors for Chagas.
excuse my poor typing!
I do know how to spell!
The insect in this photograph is indeed a wheel bug.
Are they poison do they bite . Should we kill them . I think not if they are killing Japanese beetles that are killing are pine and other tress
They might bite if carelessly handled, but they are not aggressive. They do not have venom.
found this bug today ,have never seen one before,looks prehistoric.found out it called a wheel bug
my son and I found one by my job in Dayton Ohio. was getting ready to take to work so my class can see it. Not now smile
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.
I forgot to mention it was in Maryland.
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.
found two one small one and one large small one was on top . found them in Atco NJ . VERY KOOL LOOKING BUG
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
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!
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.
We have at least four postings on our site of Wheel Bugs eating Japanese Beetles, so you are probably right that there is a connection, but we do believe in the interconnectivity of all things on our fragile planet.
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.
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.
Perhaps our predatory native species will help control the spread of the invasive Spotted Lanternfly
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.