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.
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
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
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
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
|Gardens, meadows, forest edges
|Flower beds, meadows
|Meadows, gardens, woodland edges
|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.
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.
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:
Their unique mouthparts and beak are used for impaling and feeding on their prey.
Ambush bugs are masters of camouflage, blending seamlessly into their environment. Their hunting strategy can be divided into two main steps:
- Ambushing: Ambush bugs position themselves on flowers or plants, patiently waiting for an unsuspecting insect to draw near.
- 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:
|Bees, aphids, flies, caterpillars
|Sharp beak for impaling prey
|Hooked front legs for capturing prey
|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:
Impact on Pollinators
While gardeners often appreciate ambush bugs, they can also have a negative impact on pollinators.
Pollinator Pros and Cons
- Ambush bugs are part of the natural ecosystem.
- They contribute to a diverse garden environment.
- Ambush bugs may prey on beneficial pollinators.
- This can lead to a reduction in pollination services.
Example of impacted pollinators:
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.
|Jagged Ambush Bugs
|Other Ambush Bugs
|Angular, jagged body contours
|Smoother body contours
|Thickened with muscles, like a praying mantis
|Less thickened forelegs
|Excellent at blending in with their environment
|Varies across species
|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:
|Up to 3/5″ long
|Thickened, like praying mantises
|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:
|Flower Crab Spiders
|Insects (Reduviidae family)
|Arachnids (Thomisidae family)
|Ambush in flowers
|Ambush in flowers
|Stout body, thickened forelegs
|Eight legs, two main body parts
|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.
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.
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.
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
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
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?
You have a great site. Can you tell me if this is an Assain Bug?
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?
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)
Ambush Bugs like the one in your photo wait camouflaged on blossoms to prey upon pollinating insects.
Letter 6 – Ambush 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
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
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
This stealth hunter is an Ambush Bug.
Letter 9 – Ambush 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.]
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.
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?
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
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
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’.
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
This is one of the strangest images we have ever received of a predatory Ambush Bug.