Ambush Bugs: All You Need to Know for a Bug-Savvy Backyard

Ambush bugs, belonging to the subfamily of assassin bugs, are fascinating insects known for their unique hunting techniques.

They possess specialized features like hooked forelegs with widened femur sections, clubbed antennae, and an expanded abdomen, which sets them apart from other assassin bugs.

These peculiar characteristics enable them to camouflage themselves amidst foliage while waiting for their prey.

Let’s explore the traits and features of these bugs that should help you make your backyard bug-savvy.

Ambush Bugs: Appearance and Preying Habits

Ambush bugs are usually found on flowers, acting as stealthy predators snatching unsuspecting insects that come to feed on nectar.

Jagged ambush bugs, also known as Phymata species, are a type of ambush bug with an angular, greenish-yellow, or brown body, and their small wings expose the jagged edges of their abdomen.

Their robust forelegs resemble the raptors of a praying mantis, making them incredibly efficient at catching their prey.

Ambush bugs are not just unique in appearance but also contribute significantly to controlling populations of garden pests like aphids, caterpillars, and flies.

As a result, they serve as a natural alternative to chemical pesticides. This makes them an essential part of a healthy ecosystem and highlights the importance of understanding their behavior and characteristics.

Overview of Ambush Bugs: Classification, Characteristics, and Colors

Classification and Taxonomy

Ambush bugs belong to the subfamily Phymatinae, within the family Reduviidae, part of the order Hemiptera and class Insecta. They are a group of insects classified under the phylum Arthropoda.

Physical Characteristics

These small predators are known for their distinctive features:

• Hooked forelegs with widened femur sections
• Clubbed antennae
• Widened back portion of the abdomen

The ambush bug’s hooked forelegs are muscular and resemble those of a praying mantis, making them adept at capturing prey.

Colors and Camouflage

Ambush bugs exhibit various colors and patterns on their bodies, such as:

• Dark colors like brown or black
• Bright colors like creamy or yellow hues
• Jagged body contours for camouflage

These color schemes help them blend into their surroundings and ambush their prey more effectively.

Habitat and Distribution

North America

In North America, ambush bugs can be found in various habitats, often hiding in flowers where they prey on insects. They are commonly seen in gardens, meadows, and forest edges.

• Habitat examples: Gardens, meadows, and forest edges
• Prey: Wasps, flies, bees, and butterflies

Mexico

Ambush bugs also inhabit Mexico, mainly in floral environments. They exhibit similar hunting habits as in North America, camouflaging themselves within flowers to catch unsuspecting insects.

• Habitat examples: Flower beds and meadows
• Prey: Bees, butterflies, and other pollinators

Canada

In Canada, ambush bugs are found in various habitats like meadows, gardens, and woodland edges, exhibiting similar behaviors as their counterparts in other regions.

• Habitat examples: Meadows, gardens, and woodland edges
• Prey: Flying insects such as bees, flies, and butterflies

	North America	México	Canada
Habitat examples	Gardens, meadows, forest edges	Flower beds, meadows	Meadows, gardens, woodland edges
Prey	Wasps, flies, bees, butterflies	Bees, butterflies, other pollinators	Bees, flies, butterflies

Life Cycle and Reproduction

Nymphs to Adults

Ambush bugs begin their lives as nymphs, which are smaller and less developed than adults. These nymphs undergo several molts, shedding their exoskeletons as they grow. Key characteristics of nymphs include:

• Smaller size
• Less developed wings
• Similar hooked forelegs to adults

Adult ambush bugs are recognizable by their stout bodies, thickened forelegs, and often bright colors.

These bugs share traits with assassin bugs but can be differentiated by their distinct hooked forelegs, clubbed antennae, and widened back portion of the abdomen.

Fertilized Eggs

The reproduction process for ambush bugs involves fertilizing eggs. Males typically deposit sperm in a spermatophore, an external package they then pass to a female. Once the eggs are fertilized, the female lays them on plants.

Hatching

Eggs eventually hatch into nymphs, and the ambush bug life cycle continues. The exact duration of the life cycle can vary among different species. Here are some key features of hatching:

• Eggs hatch on plants
• Nymphs emerge upon hatching
• The life cycle duration varies among species

Overall, the life cycle and reproduction of ambush bugs showcase the insects’ diversity and adaptability in the natural world.

Diet and Hunting Techniques

Prey and Predators

Ambush bugs, with their sharp beaks and hooked forelegs, predominantly prey on other insects such as:

• Bees
• Aphids
• Flies
• Caterpillars

Their unique mouthparts and beak are used for impaling and feeding on their prey.

Hunting Strategy

Ambush bugs are masters of camouflage, blending seamlessly into their environment. Their hunting strategy can be divided into two main steps:

1. Ambushing: Ambush bugs position themselves on flowers or plants, patiently waiting for an unsuspecting insect to draw near.
2. Capture: With lightning-fast reflexes, the ambush bug uses its hooked forelegs to snatch the prey. Then, it uses its sharp beak to deliver a quick, lethal bite.

Here’s a table outlining key features of the ambush bug’s prey and hunting techniques:

Feature	Description
Prey	Bees, aphids, flies, caterpillars
Mouthparts	Sharp beak for impaling prey
Forelegs	Hooked front legs for capturing prey
Hunting Strategy	Ambush and seize

Ambush bugs are unique in their hunting style and adaptability, making them a fascinating subject to study.

Roles of Ambush Bugs in the Ecosystem

Benefits to Gardeners

• Ambush bugs are beneficial insect predators in the garden.
• They feed on a variety of pests, reducing their populations and helping to maintain balance.

Examples of pests they prey on:

• Aphids
• Beetles
• Caterpillars

Impact on Pollinators

While gardeners often appreciate ambush bugs, they can also have a negative impact on pollinators.

Pollinator Pros and Cons

Pros:

• Ambush bugs are part of the natural ecosystem.
• They contribute to a diverse garden environment.

Cons:

• Ambush bugs may prey on beneficial pollinators.
• This can lead to a reduction in pollination services.

Example of impacted pollinators:

• Bees
• Butterflies
• Beetles

Ambush bugs are commonly found on composite flowers in the garden. These flowers provide the perfect hunting grounds for ambush bugs. They are also an important food source for pollinators.

Therefore, ambush bugs play a crucial role in the ecosystem as beneficial insect predators, helping gardeners control pests in their gardens.

However, their presence can also have a negative impact on pollinators, leading to potential pollination issues.

As a result, gardeners need to consider the balance between beneficial insect predators and pollinators in their environment.

Notable Species and Varieties

Jagged Ambush Bugs

Jagged ambush bugs, also known as Phymata spp, are small but mighty predators in gardens. They have a unique appearance and hunting abilities.

Take a look at the key attributes of ambush bugs.

• Length: 8 to 11 millimeters
• Coloration: Greenish yellow, white, and brown
• Wings: Small, exposing jagged sides of their abdomens
• Forelegs: Thickened with muscles, resembling a praying mantis

These bugs are efficient predators, using their raptorial forelegs to capture prey like flies and bees.

The jagged contour of their bodies helps camouflage them in their environment, making them effective ambush predators.

One example of a jagged ambush bug is the Phymata pennsylvanica, which, like other ambush bugs, has an angular body and powerful forelegs for hunting prey.

They can be found on flowers or foliage, blending in well with their surroundings.

Comparison Table

Feature	Jagged Ambush Bugs	Other Ambush Bugs
Body shape	Angular, jagged body contours	Smoother body contours
Forelegs	Thickened with muscles, like a praying mantis	Less thickened forelegs
Camouflage	Excellent at blending in with their environment	Varies across species
Ambush strategy	Highly efficient in capturing prey	May be less efficient than jagged ambush bugs

Jagged ambush bugs share some traits with other ambush bugs, such as their subfamily in the assassin bug family and clubbed antennae.

However, their unique jagged body contours differentiate them from other species, making them stand out in the world of insects.

Lophoscutus and macrocephalus are two additional genera of ambush bugs that also exhibit effective ambush-hunting strategies.

While they may not be as well-known as the jagged ambush bugs, they showcase the diversity and effectiveness of ambush bugs as predators.

Comparison of Ambush Bugs to Other Insects

Ambush Bugs vs Assassin Bugs

Ambush bugs and assassin bugs both belong to the Reduviidae family. However, they differ in appearance and hunting strategies. Here’s a short comparison of the two:

• Size: Ambush bugs are shorter, measuring up to 3/5″ long, while assassin bugs are typically larger¹².
• Appearance: Ambush bugs have stout bodies, thickened forelegs similar to praying mantises, and lack a distinct neck. Assassin bugs have a more elongated body and a visible neck¹.
• Color: Ambush bugs come in various colors – dark, creamy, or bright yellow. Assassin bugs are generally brown or gray²³.

Some key differences are shown in this table:

Feature	Ambush Bugs	Assassin Bugs
Size	Up to 3/5″ long	Larger
Body Shape	Stout	Elongated
Forelegs	Thickened, like praying mantises	Slender
Neck	Not distinct	Distinct
Color	Dark, creamy or bright yellow	Brown or gray

Ambush Bugs vs Flower Crab Spiders

Ambush bugs and flower crab spiders are predators that use camouflage and ambush tactics when hunting for prey.

• Classification: Ambush bugs are insects belonging to the Reduviidae family. Flower crab spiders are arachnids and belong to the Thomisidae family⁴.
• Hunting Method: Both ambush bugs and flower crab spiders capture prey by waiting in flowers and ambushing their victims when they come close⁵⁴.
• Appearance: Ambush bugs have stout bodies and thickened forelegs, while flower crab spiders have eight legs and two main body parts like other spiders¹⁴.
• Size: Ambush bugs can measure up to 3/5″ long, while flower crab spiders range in size from 3-10 millimeters long¹⁴.

Here’s a comparison table:

Feature	Ambush Bugs	Flower Crab Spiders
Classification	Insects (Reduviidae family)	Arachnids (Thomisidae family)
Hunting Method	Ambush in flowers	Ambush in flowers
Appearance	Stout body, thickened forelegs	Eight legs, two main body parts
Size	Up to 3/5″ long	3-10 millimeters long

Other Interesting Ambush Bug Facts

Ambush bugs are often found on goldenrod plants, a common place where they wait for their prey.

They undergo a simple metamorphosis process, enabling them to quickly develop from nymphs to adults.

These insects have distinctive clubbed antennae, setting them apart from other invertebrates.

They belong to the Animalia kingdom and the Arthropoda phylum, within the class Insecta.

Ambush bugs come in various colors, such as white, yellow, brown, and green. Some may even have a spotted appearance.

Though they can fly, these bugs typically rely on their praying mantis-like forelegs to capture prey.

They are considered land invertebrates in Missouri, where they share their habitat with other creatures such as crayfish, shrimp, millipedes, centipedes, mites, and spiders.

Part of the Reduviidae family, ambush bugs are related to the larger assassin bugs, including the notable wheel bug.

Conclusion

Ambush bugs are fascinating insects that possess unique hunting techniques and specialized features, such as hooked forelegs and an expanded abdomen. They play a significant role in controlling garden pests and serve as natural alternatives to chemical pesticides.

While beneficial to gardeners, their presence can have a negative impact on pollinators, highlighting the need for balance in the ecosystem.

Ambush bugs showcase diversity and adaptability in their life cycle, diet, and hunting strategies. Understanding these insects can help create a bug-savvy backyard that promotes a healthy and thriving ecosystem.

Readers’ Mail

Over the years, whatsthatbug.com has received hundreds of letters and some beautiful images asking us about Ambush bugs. Scroll down to have a look at some of them.

Letter 1 – Ambush Bug

Not a nice bug
This morning (8/3/04) I had an ugly encounter with this bug. It bit me on the back of the neck. I think it might be an assassin bug because it resembles the pictures of the other assassin bugs on your site.

However, the colors on it are very bright yellows and neon greens on black. The first set of legs are thick and curved; the rest are thin and straight. It has the mouth parts of an assassin.

Its bite felt like a BAD bee sting. I thought that I would share and see if you could confirm what it is.

I have it displayed on the bulletin board for my fifth grade class and I would love to be able to tell them with certainty what it is.
Thank You,
Meredith Barthel

Hi Meredith,
You have an Ambush Bug, Family Phymatidae. These are True Bugs and closely related to Assasin Bugs, hence the similarity in appearance.

According to Borror and Delong: “The Phymatids are small stout-bodied bugs with raptorial front legs. … Most of the Ambush Bugs are about 1/2 inch in length or less, yet they are able to capture insects as large as fair-sized bumble bees. they lie in wait for their prey on flowers, particularly goldenrod, where they are excellently concealed by their greenish yellow color.

They feed principally on relatively large bees, wasps, and flies.” They do have venom, hence the pain in your bite. As you know, their bite is painful, but not dangerous. I believe your species is Phymata erosa.

Letter 2 – Jagged Ambush Bug eats Skipper

The Armored Assassin
Location: Mid-Missouri
October 29, 2010 9:34 pm
While I love all bugs, I think one of my favorite has to be the Ambush Bug. It is just a armored shell of terror. He sits hidden inside or behind a flower bloom waiting for his prey to land for their last sip of nectar.

He emits a type of authority and force like I rarely see in the insect world. Sure, all Assassin Bugs are made up of terror to other insects, but to me, none give that incredible look of strength in the same way as the Ambush Bug.

For me, this is as good as it gets and I feel fortunate to have had about half a dozen sightings of them this year..many times with prey in hand.

Here are 3 of my favorite pictures from the past couple months of my favorite assassin bug….if not my favorite bug, period.
My ID: Jagged Ambush Bug – Phymata fasciata (I’m certain on Phymata, fairly certain on Phymata fasciata).
Signature: Nathanael Siders

Hi Nathanael,
Thanks again for submitting some wonderful images as well as your first hand observations.  Ambush Bugs were originally classified in their own family, but recent years have seen a change in the taxonomy, and they are now a subfamily of the Assassin Bugs. 

We agree that this is a Jagged Ambush Bug in the genus Phymata, though we do not feel qualified enough to determine the exact species as the members of the genus are all quite similar. 

Can you recall the identity of the prey in your one photo?  It appears to be a Skipper butterfly.

You are correct, it was a skipper that became his meal.  I have also seen them eating syrphids a good bit around my house.

Letter 3 – Ambush Bug

What this bug?
Hello,
You have a great site. Can you tell me if this is an Assain Bug?
Thank You
Lynn

Hi Lynn,
You are close. Not an Assasin Bug but an Ambush Bug, Family Phymatidae. Your photo shows the four segmented clubbed antennae nicely. They wait on flowers and ambush flying insects many times their own diminutive size.

Letter 4 – Ambush Bug

Bizarre yellow bug with red eyes!
September 14, 2009
We found this little guy/gal (1/4 or 1/8 of an inch long) on some flowers in the yard. I have never seen anything like it before in my life. Does anyone know what the heck this thing is?
Nessa
SW Missouri

Hi Nessa,
This is a predatory Assassin Bug known as an Ambush Bug.  Not too long ago, Ambush Bugs were classified in their own family, but they have recently been downgraded to the subfamily Phymatinae of the Assassin Bug family Reduviidae.  True to their name, the camouflaged Ambush Bugs will wait on flowers until a pollinating insect arrives to feed.

Letter 5 – Ambush Bug

identify yellow & red sunflower insect
Location:  Trinidad, Colorado
August 9, 2010 5:05 pm
First time I’ve seen these on my sunflowers, they blend in very well, tend to stay on the seedheads or right next to the petals.
Found August 1, 2010 in Trinidad, Colorado (on the New Mexico border in central colorado)
elevation 6500ft
Karen Howl

Hi Karen,
Ambush Bugs like the one in your photo wait camouflaged on blossoms to prey upon pollinating insects.

Letter 6 – Ambush Bug

Wierd Bug
Location:  Ft Collins, CO
October 16, 2010 8:56 pm
This bug was located in Ft. Collins CO, living on a Marigold flower.
Signature:  Ft Collins

Dear Ft Collins,
This is an Ambush Bug, a stealth predator that often sits on blossoms waiting to prey upon pollinating insects. 

Ambush Bugs were originally classified as a distinct family, but the group has recently undergone a revision of taxonomy and they are considered to be a subfamily of the Assassin Bugs.

Letter 7 – Ambush Bug

Subject: Unusual insect – found in KY
Location: Louisville, KY
July 23, 2012 6:15 am
Dear Bugman,
I was out doing some macro photography at a local arboretum outside of Louisville, Ky. when I found this little critter hanging out on the side of a coneflower.
I have seen one like it before, only white, hiding on some purple milkweed but I have no idea what they are. Any ideas?
Signature: John S

Hi John,
This effective camouflage artist is an Ambush Bug, a predatory species that often waits on blossoms for prey. 

The coloration of Ambush Bugs often closely matches the blossoms upon which it waits.  The blossoms on the milkweed you mentioned were most likely closer in coloration to the Ambush Bug that resided there.

Letter 8 – Ambush Bug

Subject: Extra Pictures
Location: Concord Township Ohio
October 24, 2012 1:03 pm
I included 3 pictures. Found this little guy in July, northeastern Ohio.
Checked a ton of sites with no luck, any ideas?
Signature: Sean Mitchell

Hi Sean,
This stealth hunter is an Ambush Bug.

Letter 9 – Ambush Bug

Subject: Dino-Sloth-Bug?
Location: Richmond, Virginia
July 28, 2013 5:20 pm
I noticed this bug about two weeks ago–possibly longer. I first took its picture with my phone a week ago today because the bug in question was so distinctive looking, kind of (in my eyes) like a miniature dinosaur–or at least, perhaps, a dinosaur-looking monster from a low budget 1950s sci-fi movie.

I took its picture again today–this time with a real camera–because, like some kind of sloth bug, it hasn’t moved from the same flower for over two weeks. That seems unusual to me.

In the first picture, note the white cocoon-like thing next to the bug.
Thanks for your help.
[This is a second submission; earlier today, the first submission, with larger image files, bogged down. If the first try actually went through and this is a repeat, I apologize for the unintended re-submission.]
Signature: E.W.

Dear E.W.,
This effective predator is an Ambush Bug in the Assassin Bug subfamily Phymatinae.  It looks like this Jagged Ambush Bug in the genus Phymata that is posted on BugGuide.  Ambush Bugs often wait on blossoms to ambush their prey.

Letter 10 – Ambush Bug

Subject: Insect with lime green diamond
Location: Houston Texas
June 6, 2014 6:50 pm
Sorry I just email you about this bug cause I thought my mom found it but it was found in Houston Texas, Not Western Nebraska.
Signature: Wick

Hi Wick
While we were pretty certain that this is an Ambush Bug, we had not seen any examples in the past with this distinctive marking.  When we searched BugGuide, we learned that Ambush Bugs in the genus Macrocephalus are characterized by this particular pattern. 

While we have no shortage of Ambush Bug images on our site, we believe this is the first documentation we have of the genus Macrocephalus, at least that we have identified to that level.

Letter 11 – Ambush Bug

Subject: What the heck is this
Location: Hamilton, Ontario
August 9, 2015 3:54 pm
My friend was out for a walk and felt something on her neck. When she brushed it away, it bit her.
What the heck is it?
Signature: Ken

Dear Ken,
This is a predatory Jagged Ambush Bug, and like most other Assassin Bugs, it might bite if carelessly handled, but the bite is not considered dangerous. 

The best way to remove an insect that might bite or sting if it is found crawling on a person is to gently blow it off with a strong exhalation.

Letter 12 – Ambush Bug

Subject: Any idea of what this insect is?
Location: Chicago Illinois
October 10, 2015 2:38 pm
I was in my garden just this past Thursday, October 7th. I live in Chicago, Illinois and was deadheading flowers and saw this insect at the base of an empty seed pod dried up dill.

At first I thought it was a tiny leaf stuck at the bottom but after a while, It had crawled up one of the stems and I was mystified. I am sending several views.

This is 1/4″ long, so very tiny, but larger than any aphid I have ever seen, plus the look of wings from the top really makes it look like something else.

I have sent an inquiry to the Chicago Botanic Garden but they have not responded Maybe I stumped them?
Thanks in advance for your help.
Signature: Janet Green

Dear Janet,
This Ambush Bug is a beneficial predator that is not uncommon, but they are often overlooked because they are such excellent camouflage artists.

Letter 13 – Ambush Bug

Subject: Wanting bug ID
Location: Tampa Bay Area, Florida
July 12, 2016 10:10 am
I was at my son’s BMX practice when I looked down at my arm and saw this little guy. He didn’t seem to fall into any major category, so I got a couple of shots with him.

The pronounced bright green claw-like appendages got my attention. It was a park-like setting with large pines around. He stayed with me for quite a while as he seemed intent to stay where he was.

The fabric is a t-shirt; between that an the hairs on my arm, you should be able to get a sense of scale—maybe not much more than a quarter inch long, and almost as wide. Any clues?
Signature: P. J. Orlando

Dear P.J.,
This is an Ambush Bug in the subfamily Phymatinae, and it is most likely a Jagged Ambush Bug in the genus Phymata, a group that according to BugGuide:  “Typically wait for prey on vegetation, especially flowers.” 

Of the genus Phymata, BugGuide notes:  “Coupling may involve several males riding around on a single female.

Sometimes it allows them to take down larger prey, although coupling individuals have been found each with their own prey as well. Mating occurs with the male mounted on the side of the female.”

Letter 14 – Ambush Bug

Subject: Unknown bug
Location: Indianapolis, Indiana
July 22, 2017 3:03 pm
Hi! Thanks for offering this service.
This bug was found in Indianapolis in June in my backyard. I was watering some milkweed and coneflower and the bug landed on my leg.
I put the little guy in a Petrie dish and she/he used its front two little arms like clubs, almost dragging them across the dish.

The other 4 legs operated normally.
Lastly, the body is green but the back is black/brown and the wings fold to create a kind of ‘t’.
Signature: John!

Dear John,
This is a predatory Ambush Bug.  Most images of Ambush Bugs on our site were taken on blossoms where the Ambush Bug waits to ambush its prey.

Letter 15 – Ambush Bug

Subject:  What is this?
Geographic location of the bug:  Taos NM
August 25, 2017
About 1/4 inch
How you want your letter signed:  Charlie

Dear Charlie,
This is one of the strangest images we have ever received of a predatory Ambush Bug.