Jagged Ambush Bug: All You Need to Know in a Nutshell

Jagged ambush bugs are fascinating garden predators that play a crucial role in controlling many pests.

Measuring between 8 to 11 millimeters in length, these insects belong to the Phymata species and display a unique, angled appearance with a mixture of greenish-yellow, white, and brown hues on their bodies.

Their small wings expose jagged sides, while their muscular, thickened forelegs closely resemble the raptors of a praying mantis.

These insects fall under the subfamily of assassin bugs, sharing numerous traits like the distinct hooked forelegs with widened femur sections, clubbed antennae, and the wide back portion of their abdomens.

Ambush bugs are stealthy hunters, patiently waiting on flowers such as Queen Anne’s lace, where they tactfully conceal themselves just beneath the umbellifer flowers to catch unsuspecting prey.

Their remarkable camouflage capabilities and predatory prowess make them an essential component of any healthy garden ecosystem.

Jagged Ambush Bug Basics

Phymata Species

Jagged ambush bugs belong to the Phymata genus, which is part of the family Reduviidae in the order Hemiptera.

These insects are known for their voracious predatory behavior, capturing their prey using their strong, raptorial front legs.

Physical Characteristics

The physical features of jagged ambush bugs include:

• Length: 8 to 11 millimeters
• Angular bodies with greenish-yellow, white, and brown colors
• Small wings which leave their jagged abdomens exposed
• Thickened, powerful forelegs that resemble praying mantis raptors

These insects typically have jagged body contours, which help them blend into their surroundings and camouflage themselves from potential prey.

Classification and Relation to True Bugs

Jagged ambush bugs are classified within the subfamily Phymatinae, which is part of the true bug order, Hemiptera.

They are related to assassin bugs and share some similarities with them.

The table below shows the comparison between jagged ambush bugs and their relatives, assassin bugs.

Feature	Jagged Ambush Bugs	Assassin Bugs
Classification	Subfamily Phymatinae	Family Reduviidae
Order	Hemiptera	Hemiptera
Forelegs	Hooked, widened femur sections	Standard, slender legs
Antennae	Clubbed	Varied forms
Abdomen width	Widened back portion	Not as wide
Body contours	Jagged edges	Smooth or less jagged

Other members of the order Hemiptera, also known as “true bugs,” include insects such as aphids, cicadas, and shield bugs.

These arthropods are characterized by their piercing and sucking mouthparts, which allow them to extract liquid food sources from plants or other organisms.

Habitat and Behavior

Hunting Strategy

Jagged Ambush Bugs (Phymata species) are tiny predators found in North America, specifically in open, sunny areas like prairies, roadsides, fields, and gardens.

These bugs capture prey with their muscular, raptor-like forelegs ¹². The main hunting strategy of these bugs is using their ambush technique.

They patiently wait for their prey to approach and then swiftly capture them, often targeting insects like small butterflies and bees.

Camouflage and Mimicry

A notable feature of Jagged Ambush Bugs is their expert camouflage abilities.

They typically hide among flowers, such as goldenrods, asters, and thistles, where they blend in with their jagged-edged, greenish-yellow, white, and brown-colored bodies.

This allows them to become almost invisible while stalking their prey³.

Key Features:

• Range: North America
• Habitat: Prairies, roadsides, fields, and gardens
• Preferred flowers: Goldenrod, aster, and thistle
• Hunting strategy: Ambush technique
• Camouflage: Jagged, greenish-yellow, white, and brown body

Diet and Prey

Feeding Mechanism

Jagged ambush bugs use their piercing-sucking mouthparts, called a proboscis, to catch and consume their prey.

This strawlike, knifelike beak allows them to efficiently pierce the exoskeleton of their prey and inject a paralyzing venom.

They then suck out the internal fluids, leaving the empty exoskeleton behind.

Common Prey Species

Ambush bugs are predators that feed on a variety of insects, such as:

• Bees (e.g. bumble bees)
• Flies
• Butterflies
• Moths
• Aphids

These bugs tend to target pollinators visiting flowers, as their prey. They also consume pests, such as aphids and caterpillars, often making them beneficial to gardeners.

However, their habit of preying on beneficial pollinators can be a drawback. Here is a comparison table of pros and cons:

Pros	Cons
Help control aphids and caterpillars	Predation of beneficial pollinators
May reduce need for chemical control	Unintentional harm to other insect species

Please note that jagged ambush bugs lay barrel-shaped eggs, which hatch into nymphs that resemble adults but with undeveloped wings.

Both nymphs and adult ambush bugs are predators and use their distinct feeding mechanisms to consume prey.

Life Cycle and Reproduction

Mating and Egg Laying

Jagged ambush bugs, like Phymata pennsylvanica and Phymata americana, exhibit a simple metamorphosis.

Their life cycle starts with mating and egg-laying. Female jagged ambush bugs lay their eggs on leaves or stems, providing a suitable environment for development.

Development From Nymph to Adult

• Nymphs hatch from the eggs and go through several molts.
• Their hooked forelegs, widened femur sections, and clubbed antennae develop progressively.
• The widened back portion and jagged body contours become more pronounced.

Once they reach adulthood, these predators use their distinct features to catch prey. For example, their hooked forelegs with widened femur sections help grasp and hold onto their victims.

Feature	Nymph	Adult
Hooked Forelegs	Developing	Fully developed
Widened Femur Sections	Developing	Fully developed
Clubbed Antennae	Developing	Fully developed
Widened Back Portion	Partially developed	Fully developed and pronounced
Jagged Body Contours	Partially developed	Fully developed and pronounced

Role in the Ecosystem

Beneficial Impacts: Pest Control

Jagged ambush bugs play an essential role in maintaining the ecosystem’s balance by acting as predators.

They feed on a variety of garden pests, which keeps their population under control.

This helps prevent potential damage to plants and reduces the need for chemical pesticides in gardens. Some of their prey includes:

• Earthworms
• Slugs
• Snails
• Crayfish
• Shrimp
• Millipedes
• Centipedes
• Mites
• Spiders

Their classification and appearance, including the unique pronotum and clubbed antennae, allow them to blend seamlessly into their habitat, making them an effective and stealthy predator.

Impact on Pollinators

Although jagged ambush bugs provide benefits to garden environments, their presence can also have negative effects on pollinators.

They are known to prey on pollinators such as bees and butterflies, which can lead to a decrease in pollination activity. This, in turn, may affect the overall health and productivity of a garden’s flowering plants.

Beneficial Aspects	Impact on Pollinators
Predator of garden pests	Prey on bees
Limit pest populations	Prey on butterflies
Reduce need for chemicals	Affect plant pollination

It is important to acknowledge both the beneficial and negative aspects of jagged ambush bugs in order to maintain a balanced ecosystem.

As gardeners and nature enthusiasts, being aware of their role in controlling pest populations and their potential impact on pollinators can help inform our decisions on how to support biodiversity.

Conclusion

To summarize, Jagged ambush bugs are predatory insects that belong to the assassin bug family.

They have a distinctive shape and coloration that help them blend in with flowers and foliage. They use their powerful front legs to grab and hold their prey, which can include bees, wasps, flies, and butterflies.

They inject their prey with saliva that paralyzes and dissolves them. Jagged ambush bugs are beneficial insects that control the population of other insects and pollinate plants.

Jagged ambush bugs are stealthy and skillful hunters that are rarely noticed by humans.

Footnotes

1. https://entomology.umn.edu/jagged-ambush-bugs ↩
2. https://mdc.mo.gov/discover-nature/field-guide/ambush-bugs ↩
3. https://extension.umd.edu/resource/ambush-bugs ↩

Reader Emails

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

Letter 1 – Mating Ambush Bugs

Love the lovin’ Ambush Bugs
I love your website! I’ve recently started photographing critters in our back yard. This is a fun one from our raspberry bushes.

Thank you for sending us your photo of mating Ambush Bugs.

Letter 2 – Mating Ambush Bugs

Bug Love
Hi, my name is Brigette and I love your site. I’ve been interested in insects since I was a little kid, and am currently an undergrad studying entomology at McGill University.

I love to photograph insects and thought you might enjoy some additions to your ‘bug love’ section. These were taken in my backyard in upstate NY. I have included some japanese beetles, craneflies, horseflies, and ambush bugs (my favorites!).

I even have some eggs as a result of the ambush bug matings, I kept several during the fall months. When introduced the males waste no time at all getting busy!
Brigette

Hi Brigette,
Wow!!! Thanks for sending us all your wonderful Bug Love images. They are most excellent.

Letter 3 – Jagged Ambush Bug

strange bug from Connecticut
Hello again from Connecticut! We’re flooding you with emails today, but it’s been a good week for bug sightings here. This insect was spotted on a wild blackberry bush while hiking with the kids.

We’ve never seen one of these and have no idea what it is. Any ideas? My son (ever the brave one) picked it up, then quickly dropped it because it bit him.

I keep trying to get him to stop touching bugs if we don’t know what they are, but he can’t seem to help himself. Thanks!
A. Ganino

Hi A. Ganino,
In the interest of equal opportunity posting, we are only responding to and posting your photo of a Jagged Ambush Bug in the genus Phymata for now. If time permits, we will address your other emails.

Letter 4 – Mating Ambush Bugs

is it some sort of mantis?
I was out shooting fall color and some insects when I came across this very small insect feeding on another insect. I didn’t really give it much thought until I was editing photos and noticed the mantis like front legs.
Jerry
Milwaukee, Wisconsin, USA

Hi Jerry,
While we have heard of many foods as being described as being “better than sex” in the case of your photograph, it seems the male Ambush Bug would rather procreate than eat. Ambush Bugs in the genus Phymata are typically found on blossoms where they wait to ambush insects attracted to the nectar and pollen.

Letter 5 – Jagged Ambush Bugs Mating

Bug Love Meets Where’s Waldo
Tue, Nov 11, 2008 at 7:49 PM
My son Sam took this picture of what he thought was an assassin bug on a flower. Later when we looked back at it we noticed that it was actually two bugs mating.

If you can zoom in it’s really a pretty amazing picture. We are wondering now if they are assassin bugs since they don’t seem much like the others on this site.

In any case, it’s one for your Bug Love. Any ideas? Thanks, as always, for your great great site!
Sam and Daddy Jim
Suburban backyard, 35 miles west of Chicago

Hi Sam and Daddy Jim,
Though they are sometimes mistaken for Assassin Bugs, Ambush Bugs are in a different family, Phymatidae.  Your pair are Jagged Ambush Bugs in the genus Phymata, and you can see more images on BugGuide.

Letter 6 – Jagged Ambush Bug

unknown insect spotted in the flower bed
Wed, Jul 1, 2009 at 4:47 PM
I snapped this photo of a strange insect in my flower bed. I have no idea what it is. This was the one and only time I’ve seen it. The paddle like front legs are interesting. You may have to zoom in a bit on the photo.
Mr. Rob
Eastern NC nearFayetteville

Dear Mr. Rob,
You have photographed a Jagged Ambush Bug in the genus Phymata.  Ambush Bugs were originally  in their own family, but they have recently been reclassified as Assassin Bugs in the family Reduviidae, and the Ambush Bugs subfamily Phymatinae.  Ambush Bugs often wait on flowers in order to ambush and eat pollinating insects.

Letter 7 – Jagged Ambush Bug

13mm, green, armored tank/assassin bug-like body, with mantid forelimbs and a turtle head.
August 26, 2009
Hello again Bugman!,
Love your site.
I was looking over a stand of ragweed today, admiring all the activity, when I noticed there was a dead fly on one flowerheads, so I began looking deeper, in between the flowers, for a crab spider or something like that…and found this instead.

It was scrunched down between flowertops as if lying in ambush. When I spread the flowers apart, it came walking out and stepped right up onto my finger.

Didn’t seem to mind me photoing it numerous times, and even let me move it to the B-B-Q grill for better contrast. It only flied away when I tried to move it back to the ragweed.

It’s about the same length as my fingernail (included for scale). I’ve never seen one of these before, but it does bear strong resemblance to the assassin bugs, except for it’s head, which is entirely different, looking more like a sea turtle from a Pixar movie.

It has forelimbs like a mantid, or possibly a tiny cicada. It was also pretty hard to the touch like a stinkbug, and kind of weighty for it’s t iny size.

Mostly translucent green with a dark band across it’s abdomen, and a hard bony shell of a thorax which has a couple of knobs that protrude forward and up much higher than it’s head.
In a word, handsome.
Thanks much, Jeff Volpert
Topeka, Kansas, USA

Hi Jeff,
It would seem that Ambush Bug is an apt common name for your insect based on your letter.  Recently Ambush Bugs have been downgraded from a family to  becoming a subfamily status of the Assassin Bugs, Phymatinae.  Your specimen is one of the Jagged Ambush Bugs in the genus Phymata.

Letter 8 – Jagged Ambush Bug

What kind of bug is this
Location:  western North Carolina–Jackson County–Appalachian Mountains
August 27, 2010 10:16 pm
Hi! I’m trying to identify this bug. Can you help? Someone suggested that it was a crab spider, but I do not think it is a spider at all b/c it doesn’t have eight legs.

I saw it about a week ago–mid August–at a friend’s farm. I only saw one and it was tucked down inside the petals of this pink flower. It is quite small and appeared to have wings.
Thank you for help!
Rosemary Peek

Hi Rosemary,
The coloration on this Ambush Bug in the subfamily Phymatinae is much lighter than we generally see, however, there is a photo of a Jagged Ambush Bug in the genus Phymata that is posted to BugGuide that is a near identical match to your specimen. 

Typically, the coloration of the Ambush Bugs is very close to that of the flowers upon which they wait so that they can ambush pollinating insects, which causes us to ponder if perhaps this may be a newly molted individual whose color will darken.

Letter 9 – Mating Ambush Bugs

Subject: 2 colors of mating ambush bugs
Location: Tonasket, WA
August 18, 2012 11:51 pm
Thanks to your awesome site, I was able to ID this couple quickly, even on dial-up!

They must have really really good eyesight because they kept hiding in the Joe-Pye Weed every time I got them in my viewfinder.

My husband took one look at the pictures and said, ” Look at the forearms, they have to be some sort of predator!”
Signature: Cathy

Hi Cathy,
We have two possible explanations for the discrepancy between the colors of these mating Ambush Bugs.  Ambush Bugs are masters of camouflage and they often match the colors of their surroundings. 

Hemipterans are often much lighter in color just after metamorphosis.  It is possible the female just completed metamorphosis to an adult and her coloration has still not darkened.  Your photos are a wonderful addition to our Bug Love tag.

Letter 10 – Mating Ambush Bugs

Subject: Mystery Love Bugs
Location: Andover, NJ
June 5, 2013 10:59 am
Hoping you can identify these two happy little insects for me. I photographed them this morning on a wild daisy in Andover (northern) NJ.

The daisy was about 1 1/2 inches across, which gives you an idea how tiny these little insects were – I couldn’t really make them out well with the naked eye. The daisy was trail-side near a lake.
Hope you can figure it out!
Signature: Deborah Bifulco

Hi Deborah,
We apologize for the delay.  We were on holiday and we are now trying to make a small dent in the 100s of identification requests that arrived during our absence from the office.  These are mating Ambush Bugs. 

Ambush Bugs were once classified in their own family, but recent taxonomy has downgraded them to a subfamily, Phymatinae, of the Assassin Bugs.  Ambush Bugs frequently stalk their prey on the blossoms of flowers.

Letter 11 – Jagged Ambush Bug

Subject: Identification please.
Location: Michigan, USA
August 18, 2014 6:43 pm
Hi Bugman,
Discovered two of these insects on my Butterfly Bush today, August 18th. One very black and spiny looking, the other displayed more detail and color.

They are 8-10mm in length. I find the mantis-like front legs of special interest. They showed little concern for my inspection of them. Thanks for your help!
Signature: Sheree Cooke

Hi Sheree,
This is a predatory Jagged Ambush Bug in the genus Phymata, and they frequently await on blossoms for prey to arrive, which means many of their victims are beneficial, pollinating insects. 

Do not be fooled by the small size of this stealth predator, as a tiny Ambush Bug is capable of subduing much larger prey, including Honey Bees.  See BugGuide for a comparable image.

Letter 12 – Jagged Ambush Bug eats Skipper

Subject: Moth Eating Bug ID
Location: Florida
September 24, 2014 6:28 am
I discovered this small insect that apparently was eating a moth tucked under a wildflower. Would love to know what it is!
Thank you!
Signature: Laura Hayes

Hi Laura,
The predator is a Jagged Ambush Bug in the genus Phymata, and the prey is a butterfly known as a Skipper, not a moth.  Ambush Bugs frequently await prey while camouflaged on blossoms.  Your images are wonderful, both the action image and the excellent use of scale.

Thank you for the prompt reply and solving my mystery. I knew that was a Skipper! I still want to think of them as moths and forget.
Laura Hayes

Letter 13 – Jagged Ambush Bug

Subject: This thing BITES!
Location: Vermont
August 7, 2016 7:04 pm
Does anyone know what kind of insect this is? Its a cross between a mantis and a wasp. It also bites!
As you can see it has wings and a round Abdomen. I had two other angles, but I sadly somehow lost them.

I unsuccessfully tried to capture it as it bit two family members. One bite on the arm was very red the next day and was about half dollar-sized.
It is light-green with a brown stripe and had mantis-like claws in the front.
Edit: https://extension.umd.edu/hgic/insects/predators-ambush-bugs
Signature: Curt

Dear Curt,
This is a Jagged Ambush Bug in the genus Phymata, and it seems you have already identified it since you included a link to Ambush Bugs in your request.  Ambush Bugs, which were once in their own family, are now classified as a subfamily of the predatory Assassin Bugs. 

Ambush Bugs often lie concealed on blossoms where they use their raptorial front legs much like a mantis to capture prey.  Though they are not aggressive towards humans, they can inflict a painful bite if carelessly handled or accidentally encountered, as you have already learned.

Letter 14 – Mating Jagged Ambush Bugs

Subject: Bug ID required
Location: Tiny Marsh, Elmvale Ontario Canada
August 15, 2016 10:43 am
Not sure what I’ve got here. Is this mating behaviour or lunch?
Signature: Ken MacDonald

Dear Ken,
These are mating Jagged Ambush Bugs in the genus Phymata, but what is interesting about the mating activity of Ambush Bugs is that it is occurring at the restaurant.  Ambush Bugs frequently sit on blossoms, where they are often quite well camouflaged, and they wait for insects to be attracted to the blossoms upon which time they are ambushed.

Letter 15 – Jagged Ambush Bug

Subject: Weird Bug
Location: Schaefferstown, Lebanon County, Pennsylvania
August 17, 2016 7:53 pm
This bug was located in south central PA on a fruit farm. I have never seen a bug like this before. Any idea what it is?
Signature: Jeremy

Dear Jeremy,
This is a Jagged Ambush Bug in the genus Phymata.  Ambush Bugs are predators that often sit camouflaged on blossoms where they await prey that they ambush and feed upon. 

Unfortunately, they do not discriminate when feeding, eating both beneficial pollinating species as well as insects that are injurious to the plants.

Letter 16 – Jagged Ambush Bug

Subject: Orange/Yellow & Black Insect w/Crab Legs…?
Location: Muskegon, Michigan
September 11, 2016 7:24 am
I’ve seen this insect in the same spot for two nights now. It appears to be a black and orange, or black and yellow, and has crab-like front legs, sort of like a predacious diver!

It measures only around 3.5 to 4 millimeters and I *think* it has wings, although I’ve never seen it move or fly from the expired lily stalk it’s on. I’d be very grateful to find out what it is and whether it’s a friend or foe to my garden(s)!

I haven’t seen anything even remotely similar to it all summer -and I’m definitely somebody who pays attention! I believe that entomology is a HUGE part of being a good horticulturist! Thank you for any clues/identification you can provide me!
Signature: Maggie Hart

Dear Maggie,
This is a predatory Jagged Ambush Bug in the genus Phymata, and like many predatory species including the Preying Mantis, the Jagged Ambush Bug is not that particular about what it preys upon, so many beneficial insects like Honey Bees can become prey, but generally speaking, we would have to say that predators are necessary to keep populations of other species in check. 

Your individual is much darker than most Jagged Ambush Bug images we have seen, but it does match this image on BugGuide of a Pennsylvania Ambush Bug, Phymata pennsylvanica, a species with a range not limited to its namesake state.

Holy smokes!
I can see the resemblance between the photo I took and the one you sent me a link to!  It’s no wonder my searches for “black and orange” or “black and yellow” insects weren’t yielding anything similar!
Thank you very much for your speedy response!
Maggie Hart

Letter 17 – Jagged Ambush Bug

Subject: Egg laying bug on eggplant leaf
Location: South central Florida
November 10, 2016 7:12 pm
I am in south central Florida on the east coast. Nov 11th. My eggplant leaf was partially rolled up. I unrolled it and found this bug and tiny black eggs.

I took a picture of this bug but can’t find any images on line that match. It was about 10 cm in length. It did not attempt to fly when I disturbed the leaf.
Signature: Kayandreak

Dear Kayandreak,
This is a beneficial, predatory, Jagged Ambush Bug.

Letter 18 – Jagged Ambush Bug

Subject: Beetle?
Location: Long Island, ny
July 23, 2017 7:11 pm
Saw thin on a cone flower
Signature: Kathy L

Dear Kathy,
Jagged Ambush Bugs like the one in your image often wait concealed on blossoms as unaware pollinating insects fall prey into their raptorial grasp.

Letter 19 – Jagged Ambush Bug from Canada

Subject: Leaf-like insect?
Location: Ancaster, Ontario, Canada
July 31, 2017 7:21 pm
Hi,
I was wondering if you could help me identify this bug. There were two of them, and they are quite strange looking. I’ve tried a Google image search but haven’t found anything.
Thanks
Signature: Mary-Ann

Dear Mary-Ann,
Your Jagged Ambush Bug images are awesome.  Jagged Ambush Bugs are stealth predators that depend upon camouflage to help them capture winged prey, often much larger than themselves.