Are Firebugs Dangerous? Why Do These Red Bugs Congregate In Large Numbers?

If you are living in Utah, you might have seen a new type of fiery red bug in your garden – the firebug. But are firebugs dangerous? Why do you suddenly see so many of them? Let’s find out.

Are you seeing groups of fiery red and black insects around your garden? These could be Pyrrhocoris apterus or the firebug. 

Firebugs mainly feed on dry seeds and plant material but are poisonous and should not be ingested.

Are Firebugs Dangerous

They can be commonly found in parts of western Europe, China, Australia, India, US, and the UK. 

However, in recent years, they have been spotted in Utah and other northern states as well (first appearing in Salt Lake County). 

What Are They? 

Firebugs are bugs belonging to the family of Pyrrhocoridae, along with 300 other species. 

They are bright red in color with black colorations on their black in the shape of a triangular formation, two huge dots, and a trapeze below. 

They have six black legs and two antennae and grow up to a size of .26 to 0.47 inches! They are conspicuous insects, and you might spot many in your garden. 

Are Firebugs Dangerous? 

The bright red and black colorations of the firebug are reminiscent of that of other insects that show off that they are dangerous (like ladybugs) – and they are!

But they do not sting or bite, and thus – they are only harmful to their own predators. 

Apart from this, they do not carry any plant diseases and are not known to disrupt plant populations. 

While they do feed on plants, they mostly eat waste and seeds (and sometimes smaller insects). Hence they aren’t pests to any common species of plants.

Are Firebugs Dangerous

Are They Poisonous?

Firebug bodies make poison within them from the plant waste they eat. In other words, these beautiful animals are poisonous, but only when ingested. 

They have very few bird predators, like finches who have evolved to digest the poison within. 

The appearance of insects with bright colors are, as always, a deterrent to most birds and other predators. However, ants and do mites feast on dead firebugs. 

Their poison has an interesting chemical formation that makes it anti-bacterial in nature. If harnessed well, it could help us replace or make antibiotics similar to penicillin. 

Do They Bite?

Firebugs do not bite! In fact, they cannot even eat solid matter with their mouth and rely mostly on liquid mush. 

They do not typically harm stored food products either. One interesting fact about them is that they can stain fabrics with their color. 

Typically, to protect themselves, they generate a foul odor or produce a fluid via vomiting, which also smells vile. 

Are Firebugs Dangerous

Why Do They Congregate?

Similar to other bugs, firebugs are known to form large congregations, sometimes at the base of plants. Sometimes these groups may have only a few bugs, but at other times you may see thousands of them. 

An onlooker finding such a large group of firebugs in one place might become alarmed at their intentions, but its nothing to be worried about.

Bugs usually release a congregation pheromone which attracts other bugs to join them. The usual reasons for such congregations can be:

  • To huddle together and use the warmth generated to ward off the cold. 
  • As a precursor to mating. 

Large clusters can be disruptive in gardens, but there are many ways to get rid of them which we’ve discussed later. 

What Do They Eat?

Firebugs have mouthparts that help them pierce into seeds and plants, from which they suck out the liquid. 

They feed on lime seeds, mallow, linden, and other plants. Since they avoid direct sunlight, you can usually find them at the base or under the leaves of these plants. 

Sometimes, they eat other smaller insects or even other firebugs.

Are Firebugs Dangerous

How to Get Rid of Them?

There are many easy ways to get rid of them:

  • Firebugs, especially young nymphs, drown easily. You can position a high-pressure jet spray toward them and wash away large congregations. 
  • Alternatively, soapy water with half a cup of soap per gallon water can kill them.
  • If you see individual firebugs inside, you can sweep them out, transport them on a mobile device or vacuum them. Beware of scaring them by poking too much, as they might release a foul odor in defense! 

Frequently Asked Questions

Do Firebugs cause damage?

Unlike beetle infestations, firebugs are not especially harmful to live plants and will not leave large holes in your leaves. 
Still, large gatherings of them can be an eyesore, and it’s best to get rid of them. Big groups can also smell bad if distressed.

How do you deal with firebugs?

Firebugs can be easily washed away using high-pressure water. Insecticides or chemicals are not needed as they are not invasive or pervasive infestations. 
However, you can use a soap-water mixture to draw them out further and kill them.

What does a firebug do?

Female firebugs lay white eggs which hatch into nymphs. After 5 instar nymph stages, they mature into an adult and have a total life span of about two years. 
A firebug spends its life eating plant waste and searching for a mate.

Do bugs feel pain when burned?

According to studies, bugs do feel pain and avoid situations that can result in painful encounters like burning or drowning. 
In fact, they even retain memories of these events if they survive. Thus, it’s safe to say that bugs do feel pain when being burned.

Wrap Up

For insect fans – firebugs can be an interesting-looking bug to study. They are typically not considered pests unless you start seeing large, chunky aggregations of many firebugs together.

However, it’s best to keep kids away as ingesting them is poisonous. Their red color makes people confuse them with Bark beetles and then treat them as beetle outbreaks. 

Besides, their many predators usually keep their number in check.

Thank you for reading. 

Reader Emails

Since these bugs are relatively new to our continent, there have been a lot of inquiries about them, and our readers have sent us many of their experiences. 

While some people were scared to see the sight of a totally new bug gathered in huge numbers, others were just interested to understand what it was and whether it caused any harm or not.

Do have a look at some of the live pictures that our readers have captured!

Letter 1 – Firebug from Israel


Subject: What is this bug Location: North Israel November 29, 2013 8:45 am Pls help me identify this bug Signature: R.S Shorrosh
Dear R.S. Shorrosh, Your insect is a Red Bug, Pyrrhocoris apterus, and it is commonly called a Firebug.  According to TrekNature, it “is a common bug in Israel. Its an Euro-Siberian species.  It can be found all over the Mediterranean region in Israel in high densities. It feeds of fruit juice and dead insect haemolymph.”

Letter 2 – Swiss Fire Bugs


Is this a ladybug? If so what kind?
The children and I just went to Europe . . .we found this bug and thought it was a Switzerland – Italian lady bug since we found it just before the Italian border in Switzerland . . . Can you tell us what it is? Any links that we can find pictures of it?
Denyse Gates
Calgary, Alberta

Hi Denyse,
This is a True Bug, a Hemipteran. They are numphs, but sorry, we do not know the species.

This Just In!!! (10/20/2005)
Was browsing your wonderful site when I saw the post about the Swiss Hemipteran Nymphs (10/19/2005). Just to let you know these are Firebugs ( Pyrrhocoris apterus). A rare species here in the UK, but more common in continental Europe. Keep up the good work
Aaron Woods
London England

Eric Eaton’s additions: (10/20/2005)
“Ok, I found out what those red and black bugs are. The common name is “fire bug.” Scientifically, they are Pyrrhocoris apterus, referring to the abbreviated wings in the adult stage. Family is the cotton stainer family Pyrrhocoridae. Lots of info on the Internet about them. ”

Letter 3 – Firebugs in Sweden


Unidentified bug living in rotten wood Location: Stockholm, Sweden September 19, 2011 8:03 am Dear sir/madam, I’m renovating my house here in Sweden and found this insect living all over the garden in rotten timber. It is red and black and the adult has two distinct black spots. It’s clearly no ladybug! So what is it? Even the local exterminator didn’t have a clue. Kind regards, Matt Signature: Matt
Hi Matt, These are Firebugs, Pyrrhocoris apterus, and they are a benign species.  We were not previously aware that they ranged as far north as Sweden.  Firebugs can form large aggregations containing both adults and nymphs.  For additional information, you can see this Guernsey website or the British Bugs website which indicates:  “This common European bug is on the northernmost edge of its range in Britain and is the sole member of its family to occur here.”  Global Twitter indicates this is not the first sighting from Sweden.    Thanks for the answer, so it’s rare then? Cool. I’m just glad it’s not after my foundations and only eating the lime seeds (we have a huge 100 year old lime in the garden). Should I let the local university know about it? Do you know which one in Stockholm would be most receptive to this? Perhaps I could get a grant to save my lime tree from demolishing my foundations through it’s root system (and therefore pay for my house to be under pinned hehe, )… Joking, of course… Thanks again, Matt Hi Matt, They are not rare.  In our previous response, we indicated that they are a “common European bug” but we do not know how frequently they are encountered in Sweden.  If you desire more local information, we would suggest contacting the nearest university with an entomology department.

Letter 4 – Fire Bug


1 cm bug in Swiss mountains
The ground was swarming with these at ~6000 feet in a meadow. The pattern looks like an African mask! Any ideas?
Al Padilla

Hi Al,
This colorful Hemipteran is a Fire Bug, Pyrrhocoris apterus. In France it is called a Gendarme.

Letter 5 – Fire Bugs from France


they’re here again!
Hello there
These smart looking bugs appear in my garden here in France every year, but I cannot find out what they are. They are about 8mm long and although this photo was taken on march 29 they seem to be full size adults and the younger (smaller) ones arrive later in the summer, but with exactly the same markings. Thanks for the website,

Hi Colin,
These are Firebugs, Pyrrhocoris apterus, a common species in continental Europe. Yours is our second letter from France today. We suspect some publicity perhaps?

Hi again, No publicity that I know of just good old google. The locals call the firebugs


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

3 thoughts on “Are Firebugs Dangerous? Why Do These Red Bugs Congregate In Large Numbers?”

Leave a Comment