What Eats Assassin Bugs? Predators Who Eat The Killer Bugs

Assassin bugs are feared predators of the common garden, but what eats assassin bugs? What preys on the predator? Let’s find out.

Assassin bugs are one of the most feared predators in the insect kingdom. These bugs are voracious and indiscriminate eaters, and often their kills are quite gruesome.

Moreover, some varieties of these bugs can bite humans and even cause Chagas disease, a harmful affliction with no known vaccine or medicine.

However, nature has a way of balancing itself, and there are no apex predators in the wild. Assassin bugs have their own predators, and it’s important to know what they are so as to control them when needed.

In this article, we will look at what eats assassin bugs and how you can use them to control the population of these insects.

What Eats These Bugs?

There are many birds, spiders, rodents, and some types of praying mantises that eat assassin bugs. Some smaller mammals, frogs, lizards, and snakes also consider them good sources of food.

There are over 7,000 species of assassin bugs with more than 120 in North America alone. So it is hard to name one predator for each type. However, in most cases, assassin bugs are between 0.2 to 1.2 inches long and are no match for larger mammals and birds.

Who Eats Their Nymphs and Larvae?

While adult assassin bugs are fearsome carnivores, their nymphs are no less. In cotton fields, they can eat as many as 160 ball worm larvae in under 12 weeks.

But the nymphs themselves are preyed upon by spiders, birds, rodents, praying mantises, and even adult assassin bugs.

The nymphs usually have long heads and big legs. Their heads are round but narrow, and they have protruding, hinged mouthparts which are used to suck the insides of their prey. In most cases, the nymphs can’t fly.

How Do They Defend Themselves When Attacked?

Remember that protruding mouthpart we talked about? That pincer-like object can deliver a painful bite to anyone trying to touch these bugs.

They use it to push their venom inside their prey, along with some digestive enzymes that turn the insides of the victim into nothing but liquids. These bugs suck in the juice created, leaving just the outer shell intact.

But when attacked, this mouthpart can also be used to defend themselves. Assassin bugs are named after their ability to deliver death to their prey in a single blow, and they also make aggressive warning sounds when they fear an attacker.

What do Assassin Bugs Eat?

Well, let us turn the table around for a bit now and talk about the amazing predatory capabilities of these bugs.

Most adults feed on a huge variety of garden insects, including caterpillars and larvae of other bugs, sawflies, leaf beetles, aphids, and so on.

They kill and eat both harmful pests and beneficial insects in the garden, so keeping them around is a bit of a double-edged sword for gardeners.

How Can You Attract Them To Your Gaden?

If you have a major infestation from one of the assassin bugs’ prey, having them around might be an interesting, non-chemical-based way to get rid of your bug problem.

To invite assassin bugs to your garden, simply follow these steps:

Turn on the lights

Assassin bugs are attracted to lights, so if you have porch lights or night lights in your garden, Keep them on at night. Moreover, many of their prey are also attracted to light, so it makes their job much easier if you already have some in your backyard.

Keep some water

Assassin bugs need water to survive, so having a small pan with water in it would help them immensely. Make sure not to buy a very deep pan. It needs to be either very shallow or filled with gravel so that it can perch on edge and sip water without falling into it.

Mulch

Some assassin bugs like to do their shady business of hunting under cover of mulch. By putting a few mounds of mulch here and there, you are giving them the perfect opportunity to hide out and get to the job you want them to do: kill pests.

Use narrow-spectrum pesticides

If you want to use other methods to kill bugs, make sure you use narrow-spectrum pesticides that are only intended to kill a specific species or type of bug. Don’t go for a wide-spectrum pesticide, which can harm the assassins as well.

Flowers

A few bugs from this family love the sight of flowers, so having a few flowers in your garden is a nice way to welcome them there. If you have a veggie plantation, having marigolds and cucumbers can really spice up the garden and attract them in large numbers. You can also use herbs and spices like dill to bring them home.

Why Might You Not Want These Bugs In Your Garden?

Now that we have discussed all the good things about these bugs let us turn our sights on some of the things you need to watch out for when you attract them to your garden.

They Bite

Assassin bugs are biters. They have developed their strong biting ability to hunt for prey, but it can work on humans as well. Some assassin bugs can even suck blood from your skin.

When the bug bites, it can cause pain, infection, and swelling in the body part. Using ice and pain meds might be a good early treatment, but if you have allergies to insect bites, get yourself to a doctor immediately.

Kissing Bugs Cause Diseases

The kissing bug is a type of assassin bug so named for its habit of biting humans on the mouth or the eyes. One bug can leave as many as 15-20 bites on your face at a time.

Kissing bug bites is usually harmless, but unfortunately, not always so. These bugs can be carriers for Chagas disease, a malady that can cause heart and liver problems, and has no cure or vaccine for it.

If left untreated, Chagas can be life-threatening, so it is best to make sure that you are not inviting kissing bugs into your home.

How to Keep Assassin Bugs Away

The easiest way to keep any bug outside your house is to make sure it has no way to enter your place. In the case of the assassin bug, this includes cracks and gaps in your walls, ceiling, windows, window frames, doors, and so on.

If you find any of these, seal them up immediately with caulk or duct tape.

Make sure you leave your pets indoors at night because assassin bugs might come inside with them. However, safety is best, so don’t sleep in the same room with your pet.

Cleanliness is another important thing when dealing with these bugs. Make sure you wash your mattresses, beddings, linens, and everything else that comes in contact with you at least 1-2 times a week.

If you have a fireplace, it is easy for these bugs to hitch a ride with some logs of wood. So makes sure you inspect your wood carefully before bringing it in.

Lastly, just like turning lights on invites these bugs to the garden, turning them off might deter them from coming to your place.

Frequently Asked Questions

How do you get rid of an assassin bug?

One option is to, of course, avoid giving them any opportunity to survive in your garden or home. Turn off your porch lights, don’t keep any open sources of water, and do not spread mulch around your garden. If you are not sure which pesticides to use, synthetic pyrethroids are one thing that might work.

What is the prey of an assassin bug?

Caterpillars, larvae, tadpoles, aphids, and other small insects and even insects bigger than assassin bugs are all potential prey to an assassin bug.

The wingless nymphs of the assassin bugs are also of a similar nature. These bugs sit quietly, waiting, and then ambush their prey, injecting a toxin into their bodies that turns their insides into liquid.

Are assassin bugs good to have around?

Yes and no. Assassin bugs are great predator insects, so if you have a particularly nasty pest in your garden, having them around might be very helpful.

On the other hand, assassin bugs can bite and even spread diseases to humans – so maintaining a safe distance is equally important.

What is special about assassin bugs?

Their voracious appetites and their ability to kill their prey with very little effort make them different from others. These bugs can bite and kill a victim with just one shot of their pincers. They are equally varied in their diets – they will eat anything from aphids to praying mantises if the chance comes along.

Wrap Up

Assassin bugs can be both helpful and harmful to your garden and home. If you are planning to bring them to your neck of the woods, make sure you know what you are getting yourself into.

These guys can clean up your garden of harmful pests, but they might be a nuisance if they get inside your house. Thank you for reading!

Reader Emails

Getting rid of bugs in natural ways is always better because it ensures that there are no harmful side effects from pesticides in the garden.

Some of our readers have shared their own views on this subject; you might like to go through them below.

Letter 1 – Ants devour Assassin Bug in Australia

Assassinated and Form Problem
July 26, 2010 8:01 PM
Hi Daniel,
Just tried submitting this picture via the form but as per last time got the error message “Failed to send your message. Please try later.”
Anyway, thought you might like this for your foodchain pages. This is an Orange Ground Assassin Bug, Ectomocoris patricius, that has come off second best to an ant colony.
regards,
Trevor

Hi Trevor,
Thanks for taking the trouble to send this image to us via different channels.  Please let us know if the form continues to give you problems when submitting photos because we do not want any interruption in our reception of the fabulous images you provide us from Australia.

Reader Emails

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

Letter 1 – Leafhopper Assassin Bug

Subject: Minding our Milkweed Mystery
Location: Southern California
August 6, 2016 5:46 pm
Hi, Bugman! We’ve been growing milkweed to attract monarch butterflies. It went well for about a month. Recently, the milkweed has been overrun by new insects, and the monarchs have stopped coming by. The new insects look a lot like milkweed bugs, but every single resource I can find insists that milkweed bugs, mature and immature, are black. The bugs on our milkweed are a very light brown. Their legs almost look translucent. Do you think it’s possible that they’re simply a variety of milkweed bug? Or are milkweed bugs absolutely always black–which would make these bugs imposters?
Signature: Rose

Dear Rose,
This looks to us to be a Leafhopper Assassin Bug, Zelus renardii, and according to BugGuide:  “Generalist predator (despite its common name suggesting host specificity).”  The good news is that it will likely prey on Oleander Aphids that often trouble milkweed in Southern California, but we would not rule out that it might also prey upon young Monarch caterpillars.  You mentioned attracting Monarch butterflies which will take nectar from many different flowers, however, the real benefit to growing milkweed in the garden is that it is the only plant upon which Monarch Caterpillars will feed.

Got it! Thank you so much for your help! Since they appear to be able to survive on other plants, we’re thinking we may pick some of them off and give them to neighbors who have an overabundance of aphids of their hands. You’ve been a great help!
Rose

Be careful Rose.  They will bite if carelessly handled.

Letter 2 – Smashed Assassin Bug

Subject: Weird new bug in North Texas
Location: N. Texas, DFW area
October 30, 2016 8:38 am
We found a new bug in our house and cannot identify it. The bug is green with long legs, red eyes and red bands around each leg near the “knee” and the “foot”. It has little wings (maybe it is a juvenile?) This is the best picture, missing a couple of legs and the body is a little beat up after my wife was either bit, stung, or pierced by this thing, and flung it to the ground. Thank you!
Signature: Devin

Dear Devin,
We have a difficult time tagging a submission as Unnecessary Carnage when that carnage occurred after the critter has inflicted a bite or sting on someone, but we still feel you should know that this was a beneficial, predatory Assassin Bug, and though they are considered beneficial, Assassin Bugs are capable of inflicting a painful bite if they are carelessly handled or accidentally encountered.  This immature Assassin Bug is a member of the genus Zelus.

Letter 3 – Sycamore Assassin Bug

Subject: Weird bug on my door
Location: western nc
November 12, 2016 6:53 am
Is this in the stink bug family? We have been bombarded by stink bugs this year.
Signature: ?stink bug

This Sycamore Assassin Bug is classified with Stink Bugs in the True Bug suborder Heteroptera, but they are in different families within the suborder.

Letter 4 – Possibly Four Spurred Assassin Bug

Subject: What is this?
Location: San Jose ca USA
December 17, 2016 2:04 pm
Just wondering what this is.
Signature: Thank you

This is a predatory Assassin Bug and we believe it is in the genus Zelus, possibly the Four Spurred Assassin Bug, Zelus tetracanthus, which is pictured on BugGuide.  Though not considered dangerous to humans, Assassin Bugs in the genus Zelus are known to deliver a painful bite if carelessly handled or accidentally encountered.

Letter 5 – Milkweed Assassin Bug from Antigua

Subject: What on earth is this bug?
Location: On my mango tree in the yard…
March 10, 2017 8:09 am
Hello Bugman,
I live in Antigua, the Caribbean. I usually spot these red and black bugs in huge amounts on the beach, but now, they are on all over my mango tree!!! Should I light my tree on fire?!??! Are they harmful? What on earth are these?
Signature: Mel

Dear Mel,
This is a beneficial Assassin Bug that will help eliminate pests from your mango tree.  We believe this is a Milkweed Assassin Bug, Zelus longipes, a North American species with a range that includes “so. US (so. Atlantic & Gulf states to so. CA) to Argentina” according to BugGuide.  Assassin Bugs might bite if carelessly handled.

Letter 6 – Sycamore Assassin Bug

Subject: Bug with striped legs
Location: New Jersey
June 30, 2017 1:38 pm
Hey there –
My mom found this bug in her dining room this summer. Any idea what it is?
Thanks,
Signature: Greg

Dear Greg,
This is a Sycamore Assassin Bug, and you should exercise caution if handling it.  Though it is not an aggressive species, the Sycamore Assassin is one species of Assassin Bug that seems to bite people with some degree of regularity.  The bite is painful, but not dangerous.

Oh boy, thanks for the help, Daniel. Have a great holiday weekend!

Letter 7 – Sycamore Assassin Bug

Subject:  What’s this bug?
Geographic location of the bug:  Tulsa, OK
Date: 11/30/2018
Time: 07:34 PM EDT
Your letter to the bugman:  About 1/2 – 3/4 of an inch long.
I’ve had this little bug hanging out in my kitchen for several days. It startled me a few times because I thought it was a spider at first.  Just curious what it is! Never seen a bug like it before.
How you want your letter signed:  Kenzie

Dear Kenzie,
This is a Sycamore Assassin Bug.  It is an outdoor, predatory insect and it will not infest your home.  Like other members of the family Sycamore Assassin Bugs should be handled with caution as they might bite if carelessly handled or if accidentally encountered in a situation where they feel threatened.

Letter 8 – Sycamore Assassin Bug

Subject:  Assassin bug or kissing bug?
Geographic location of the bug:  North Virginia
Date: 04/26/2019
Time: 02:37 PM EDT
Your letter to the bugman:  On April 26, I saw this bug in my mail box and thought it looked interesting so I took a few pictures of it. But just today, I saw a news post about the Kissing Bug and tried to search around to find out if it was. I ended up finding another article on here dating back to April 2016 with a photo of a similar looking bug called the Assassin bug or something like that. Can you please help me identify this bug?
Thank you~
How you want your letter signed:  Liya

Dear Liya,
This is a Sycamore Assassin Bug in the genus Pselliopus, and like other members of the Assassin Bug family Reduviidae, it might bite if carelessly handled, but the bite is not considered dangerous.  Kissing Bugs are also Assassin Bugs, but they prey upon warm blooded hosts.  Kissing Bugs will readily bite humans and especially those found in warmer regions can spread Chagas Disease.

Letter 9 – Milkweed Assassin Bug

Subject:  Bug identification
Geographic location of the bug:  Florida
Date: 06/11/2019
Time: 05:46 PM EDT
Your letter to the bugman:  This guy was crawling around on my patio table, was wondering what it might be!
How you want your letter signed:  Tina

Dear Tina,
This is a beneficial, predatory Milkweed Assassin Bug, and like other Assassin Bugs, it should be handled with caution as it might bite if provoked.  The bite is reported to be painful, but is not considered dangerous.

Letter 10 – Spined Assassin Bug in Dried-Up Foliage Pose

Subject:  Very odd looking bug
Geographic location of the bug:  Council Bluffs, IA
Date: 11/26/2019
Time: 11:40 PM EDT
Your letter to the bugman:  Found this guy on my front door mid last summer. I’m getting better at identifying, but this one has me stumped..
How you want your letter signed:  Wendy Starrett

Dear Wendy,
This is a predatory Assassin Bug in the family Reduviidae, and we believe it is a Spined Assassin Bug in the genus Sinea, possibly Sinea diadema which is pictured on BugGuide.  The folded antennae are quite unusual.  We will attempt to get a second opinion.

Eric Eaton Confirms:
Yes, Sinea sp. in typical “you can’t see me, I’m dried-up foliage” pose.  LOL! …
Eric

Letter 11 – Assassin Bug from Bolivia is Zelurus festivus

Subject:  Spikey wasp? Coral caterpillar
Geographic location of the bug:  Bolivia, Ascensión de Guarayos and Trinidad
Date: 12/13/2019
Time: 05:57 AM EDT
Your letter to the bugman:  Hi Bugman. I have spent the last year working at an animal sanctuary in the Bolivian jungle which means I encounter a huge amount of strange insects daily. These two particularly caught my attention and would love to know what they are. Many thanks
How you want your letter signed:  Chris

Dear Chris,
What you have mistaken for a “spikey wasp” is actually a stunning looking Assassin Bug, but we have not had any luck with a species identification.  We can assure you that this is NOT a Blood-sucking Conenose Bug or Kissing Bug from the subfamily Triatominae, a group known to spread Chagas Disease.  Many Assassin Bugs will deliver a painful bite if provoked or carelessly handled, but except for the Kissing Bugs, Assassin Bugs do not pose a threat to humans.  This individual is a very effective wasp mimic.  Perhaps Cesar Crash from Insetolgia will recognize it.  We will attempt to identify your Caterpillar at a later time.

Update: December 20, 2019
Thanks to Cesar Crash and Brandon Thorpe submitting comments, we now know this is Zelurus festivus.  There are also images on iNaturalist and Discover Life.

Letter 12 – Probably Common Assassin Bug from Australia

Subject:  a solitary bug i never see before
Geographic location of the bug:  100kms North of Sydney..Coastal.
Date: 10/18/2021
Time: 12:30 AM EDT
Your letter to the bugman:  Hi bugman
i am always curious about the natural world, as so many of us love it’s minds blowing divetsity and the adaptation of the countless living forms to their niche..
so perhaps you can help..
i never saw a bug like this in my backyard in Woy Woy..NSW. Australia
How you want your letter signed:  i don’t know what this means

This is a predatory Assassin Bug in the family Reduviidae.  We cannot identify the species, but there are some similar looking individuals on the Brisbane Insect website.

Update:  Thanks to a comment from Cesar Crash, we are in consensus that the closest match Pristhesancus plagipennis is which is pictured on Jungle Dragon.