Boxelder Bug: All You Need to Know in a Nutshell

Boxelder bugs are true bugs that often become a nuisance around homes and buildings located near plantings of boxelder trees, as well as ash and maple trees.

These insects typically congregate in large numbers on the south side of trees and buildings as the fall season approaches, sometimes becoming a pest issue in areas where their infestations are heavy.

These bugs belong to the same order as stink bugs, cicadas, and other insects with piercing and sucking mouthparts.

One distinctive characteristic of boxelder bugs is the bad odor they release when crushed.

Their population varies from year to year, often experiencing spikes in abundance during hot, dry summers.

Boxelder bugs feed primarily on female boxelder trees by sucking sap from leaves, tender twigs, and developing seeds.

In addition to boxelder trees, they may also occasionally be found on ash and maple trees, as well as raspberry and strawberry plants.

Although their feeding habits typically don’t cause severe damage to the host plants, they can still be a nuisance for homeowners.

What Are Boxelder Bugs?

Boxelder bugs are a species of insects belonging to the Rhopalidae family.

They are commonly found near boxelder trees and can be a nuisance to homeowners.

Two Life Stages: Adults and Nymphs

There are two life stages in boxelder bugs: adults and nymphs.

Adult boxelder bugs are fully grown and have a more defined appearance, while nymphs are immature and still developing.

Both adults and nymphs feed on primarily boxelder trees, sucking sap from leaves, tender twigs, and developing seeds.

Adult Boxelder Bug

Physical Characteristics

Boxelder bugs have the following distinct physical characteristics.


  • Dull black in color
  • Marked with red (orange) along the edges of their front wings
  • Oval-shaped body with a length of about ½ inch
  • Six legs and two antennae


  • Red and black in color
  • Short wing pads
  • Six legs and two antennae
Adults Nymphs
Color Dull black with redmarks Red and black
Length About ½ inch Smaller
Wings Fully developed Short wing pads

Boxelder bugs are a true bug of the species Boisea trivittata, closely related to the western boxelder bug (Boisea rubrolineata).

Both species share similar characteristics, with red markings on their bodies, and are commonly found near boxelder trees.

Western Boxelder Bug

Habitat and Behavior

Life Cycle

Boxelder bugs have a simple life cycle. Eggs are laid by females, starting light yellow and darkening to rusty red. Nymphs hatch and develop into adults, feeding on seeds and vegetation.

Seasonal Activity

Boxelder bugs show distinct behaviors depending on the season:


  • Congregate in large numbers on the south sides of trees and buildings for warmth
  • Seek shelter in homes or buildings to overwinter


  • Hibernate, remaining generally inactive

Sunlight and Swarms:

  • On sunny winter days, they might become active and swarm in large numbers

Boxelder bugs prefer to remain on specific host trees, which include:

  • Primary hosts: Boxelder Trees and Acer negundo
  • Secondary hosts: Ash and Maple Trees, as well as other Acer species
Eastern Boxelder Bug

Impact on Humans and Environment

Harm to Plants and Crops

While these bugs do not cause major damage to plants, they can cause some harm to certain horticultural crops such as:

  • Raspberry
  • Strawberry

In these cases, boxelder bugs may suck sap from leaves and tender twigs, as well as feed on developing seeds.

However, the overall damage is usually minimal and not considered serious in the agricultural sector.

Interaction with Humans

Boxelder bugs do not pose any significant risk to humans. Some key points to note are:

However, they can be annoying when they enter the domestic environment.

During the fall, boxelder bugs tend to congregate in large numbers on the south side of homes and buildings.

They might enter the house looking for shelter, but they are still considered harmless to humans.

Why They Are Attracted to Homes?

Feeding Habits

Boxelder bugs are attracted to homes primarily due to their feeding habits.

They prefer areas close to their preferred food source, which could be the reason they find their way into nearby homes.

These pests are known to feed on the seeds and leaves of boxelder, maple, and ash trees.

They might also target fruit trees like apples and peaches, causing damage to the plants and fruits.

  • Boxelder bugs feed on seed-bearing boxelder trees.
  • Maple and ash trees are also liable to infestation by these pests.

Infestation Patterns

Boxelder bug infestations are more likely during hot, dry summers, with their populations skyrocketing during such conditions.

These pests reproduce on female boxelder trees and sometimes on maple and ash trees.

  • Higher infestations occur during hot, dry summers.
  • Female boxelder trees are the primary site for reproduction.

Preventing Boxelder Bug Infestation

Sealing Your Home

To prevent boxelder bugs from entering your home, it’s crucial to seal off potential entry points. These pests often seek shelter in homes through:

  • Crevices and gaps around doors and windows
  • Damaged or worn-out screens
  • Cracks in siding or foundation

For example, use door sweeps, caulk, or weatherstripping to seal gaps where insects might enter.

Replace damaged window screens and repair any cracks in foundations or siding.

Planting Strategies

Managing vegetation around your house can also help eliminate boxelder bug infestations:

  • Remove female boxelder trees, which attract boxelder bugs due to their seed-bearing nature
  • Limit planting of ash and maple trees near the house, as these may also be targeted by boxelder bugs
  • Maintain a clutter-free yard to eliminate potential hiding spots
Eastern Boxelder Bug

Use of Insecticides and Pesticides

Insecticides and pesticides can provide a temporary solution, but they may not be the most effective long-term method. Some drawbacks include:

  • Ineffectiveness: Boxelder bugs can become resistant to certain chemicals
  • Environmental harm: Some pesticides pose risks for other animals or plants
  • Health concerns: Prolonged exposure to chemicals can pose a threat to homeowners

On the other hand, using diatomaceous earth, a natural product, can be a safer way to combat boxelder bugs. It is a non-toxic alternative that causes bugs to dehydrate and die.

Removing and Managing Boxelder Bugs

Natural Remedies

Boxelder bugs can be managed through natural means.

One such method is to remove their primary food source, the female boxelder tree, or seed-bearing trees like ash and maple.

Another natural remedy is to create a mixture of soap and water, which can be sprayed on the bugs to kill them without harming your plants.

Vacuuming and Cleaning

To help prevent infestations, regularly vacuum walls and windows where boxelder bugs tend to congregate, especially during the overwintering period.

Be sure to clean any surfaces where nymphs, adults, and eggs may be present, such as window sills and door frames.

Pest Control Services

If boxelder bug infestations become severe, consider hiring a professional pest control service.

They can provide specialized treatments for your home or building, which may include chemical applications or other forms of extermination.

Pros of pest control services:

  • Highly effective
  • Performed by trained professionals

Cons of pest control services:

  • May be costly
  • Potential chemical exposure
Natural Remedies Vacuuming and Cleaning Pest Control Services
Effectiveness Moderate Moderate High
Environmental Impact Low Low Moderate
Effort Required Moderate High Low
Cost Low Low High

By following these methods, you can effectively reduce and manage boxelder bug infestations in your home or building.

Remember, it’s essential to choose a management method appropriate for the severity of the problem and the specific needs of your situation.

Common Misconceptions

Boxelder bugs are often misunderstood, with many misconceptions surrounding their behavior and impact on our environment. Let’s debunk some common myths:

Myth 1: Boxelder bugs are harmful to fruit trees.

Despite popular belief, boxelder bugs mainly feed on boxelder trees and occasionally ash and maple trees. They do not cause significant damage to fruit trees like apples and peaches.

Myth 2: Boxelder bugs are beetles or mosquitos.

These insects belong to the true bug family, which includes stink bugs and cicadas, not beetles or mosquitoes. Dermestid beetles are entirely different pests.

Myth 3: Homeowners must use insecticides to control boxelder bugs.

While insecticides can be effective in controlling these bugs, many non-chemical methods exist.

Prevention and physical removal are often sufficient to manage their populations.

Here’s a short comparison table to clarify some differences between boxelder bugs and dermestid beetles:

Boxelder Bug Dermestid Beetle
Mainly feed on boxelder trees Feed on animal products and dry goods
Belong to the true bug family Members of the beetle family
Release a bad odor when crushed No distinct odor when crushed
Harmless to most home environments Can cause damage to stored goods


Boxelder bugs, scientifically known as Boisea trivittata, are true bugs commonly found near boxelder, ash, and maple trees.

While they can become a nuisance in homes, especially during the fall, they are harmless to humans and do not cause significant damage to plants.

Their distinctive red markings and unique behavior patterns, such as releasing a pungent odor when crushed, make them easily identifiable.

Homeowners can manage their presence through various preventive measures and natural remedies.

Reader Emails

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

Letter 1 – Possibly African Cluster Bug and Western Boxelder Bug

Subject: Brown Marmorated Stink Bug Variant?
Location: Portland, Oregon
November 11, 2016 5:09 pm
These two hemipterans were playing touchy-feely near Portland, Oregon. One is obviously a Western Boxelder bug, but the other one is leaving me slightly perplexed. Although the photograph doesn’t do it justice, the shield bug was essentially black and gold, almost as if highlighted with goldleaf.

I suspect it is just a variant of the brown marmorated stink bug; I’ve seen ones with brownish, or reddish, or greenish hues, but never one that that seemed to sparkle in the sun. In any case, after about a minute of inter-species investigation the two bugs went their separate ways.

Your thoughts? I know you’re probably inundated with identification requests, so if this is just another BMSB, please feel free to ignore the inquiry.
Signature: David Hopkins

Stink Bug and Western Boxelder Bug
Stink Bug and Western Boxelder Bug

Dear David,
We have corrected the spelling error you requested.  In our opinion, this is NOT a Brown Marmorated Stink Bug because according to BugGuide:  “The brown mottled color and banded antennae are distinctive” and your individual has solid colored antennae. 

This might be an African Cluster Bug, Agonoscelis puberula, which we found on BugGuide, though BugGuide does not list the range for this invasive species in Oregon at this time.  Our biggest doubt regarding that as the identification is that BugGuide indicates it is “very pubescent” or hairy, and your individual appears to be quite smooth in your high quality image. 

So, for now we cannot commit to a species identification, and we really like your inter-species investigation with the Western Boxelder Bug.

Possibly African Cluster Bug and Western Boxelder Bug
Possibly African Cluster Bug and Western Boxelder Bug

Thanks for your very prompt reply, Daniel.  I noticed the lack of antennal banding, as well, although there does seem to be some variation in the widths of the light and dark bands on the brown marmorated stink bug.

With a little imagination (well, with a lot of imagination, actually) hints of white at the antennal joints might be made out, but not enough to be considered banding.

I think you’re right that it’s probably not an African Cluster Bug; not only is it not very pubescent, it lacks the light “Y” or trident shape commonly seen on the scutellum.  For now, let’s call it Verus mysterium!

Letter 2 – Mating Eastern Boxelder Bugs

Bug love (Boxelder style)
July 26, 2009
I belive these to be, Boisea trivitata. Having a little fun on my screen. Just outside, is a boxelder tree, where there are thousands more. Can’t tell which is male, and which is female. Can you help?
Mound, MN

Mating Boxelder Bugs
Mating Boxelder Bugs

Hi Terry,
Thanks for sending us your photo of mating Eastern Boxelder Bugs.  We almost never get submissions from people who know what they are, but rather they want the large congregations of insects in their yards identified. 

We are especially fond of some of the alternative names for Eastern Boxelder Bugs, including Democrat Bug, Populist Bug, Politician Bug.  According to BugGuide:  “Apparently these political terms are primarily used in the Central Plains states as I’ve seen references to such from KAN, NEB, & IOWA. “

Letter 3 – Mating Western Box-elder Bugs

what are these flying bugs?
Hi Bugman, you’ve got a great website! Can you tell me about the bugs that are in my yard by the thousands? They’re all over the Portland, OR area.

They don’t seem to bite, but are terribly annoying. They’re about 3/4 inch long and when flying, a bright orange body is visible. Are they likely to leave soon?
Thanks for the info,

Hi Bev,
You have Western Box-elder Bugs, Boisea rubrolineata. It feeds on Box-elder, Ash and Maple. Adults and nymphs aggregate in huge numbers, and often get inside homes to hibernate. They are difficult to erradicate, and since you have mating activity, you are well assured of future generations.

Letter 4 – More Democrat Bugs

Subject: Is this a democrat bug?
Location: Springfield Missouri
September 29, 2012 8:59 am
I can’t tell from the picture on your website if this is an eastern box… bug I would just like a confirmation. These were found outside of my workplace in downtown Springfield Missouri.
Signature: CuriousKids

Eastern Boxelder Bugs

Dear CuriousKids,
Your identification is correct.  This is an aggregation of Eastern Boxelder Bugs which are sometimes called Democrat Bugs.  Your individuals are all immature nymphs, though at various stages of development or instars. 

Adult Eastern Boxelder Bugs have black wings with some red veins.  Sightings this year have been plentiful.

Letter 5 – Mating Boxelder Bugs

Subject: Box Elder Bug Love
Location: Monmouth County, NJ
May 22, 2016 8:46 pm
At first I thought these were beetles, but after a bit of google research I have come to think they are Box Elder Bugs. I found them like this on my window screen (mating?) where they stayed for 2-3 days with little movement.
I was unable to get a photo of the top side (or even see it), but I spotted another one about a week later and after viewing its top side it appeared to be a box elder bug.
Location: Monmouth County, NJ
Time: Around the last week of April
Signature: Anonymous

Mating Boxelder Bugs
Mating Boxelder Bugs

Dear Anonymous,
A ventral view is not ideal for an exact identification, but the red eyes that are clearly visible on the pair in your image and in this BugGuide image are a very strong indication that they are mating Boxelder Bugs.

Letter 6 – Populist Bugs Swarming in Ohio

Subject:  What is this
Geographic location of the bug:  Ohio
Date: 11/05/2017
Time: 09:20 PM EDT
Swarming in Akron
How you want your letter signed:  Aaa

Eastern Boxelder Bug

Dear Aaa,
This is an Eastern Boxelder Bug, sometimes called a Populist Bug or Democrat Bug because of the large number of individuals that aggregate together, often in the autumn on light colored walls with sunny exposures. 

Eastern Boxelder Bugs are also known to enter homes to hibernate when the weather begins to cool.  Interestingly, the Western Boxelder Bug is our current Bug of the Month.

Letter 7 – Soap against Boxelder Bugs



Hi Debbie,
Thanks for the great tip. I’m sure our readers will love it. We are posting it at the top of the True Bug page. Incidentally, Boxelder Bugs are True Bugs and not Beetles.

Letter 8 – Soap Against Boxelder Bugs: Another Endorsement!

box elder bugs
Hi, I just wanted to confirm that box elder bugs can be killed very inexpensively at home with warm water and dish-soap. Approximately 1/8th cup to a sprayer of warm water. Dawn works best as it has detergents that can penetrate the oily substance on the box-elder bugs backs.

It will stick to them and suffocate the bugs It is funny to watch them fall from their perches in clumps after a soaking! We had an unbelievable infestation from my new neighbor’s mulch delivery. They covered our tree (golden showers) and moved to our the front of the house.

This is a very well tested remedy! You may have to repeat as these bugs have a lengthy life cycle. Seems it took me an entire summer to get the tiny crawling nymphs without wings to the medium sized and adult with wings.

Letter 9 – THEY’RE HERE: Boxelder Bugs

What are these red bugs, please?
Dearest Bug People,
Thank you! I have found your site to be very useful and enjoyable. You have helped me feel peaceful about the spiders and house centipedes waging war (against one another) in my cellar. I’m excited to finally have a reason to write you; all other times I have been able to identify mystery bugs myself, using your information.

Regarding the attached photos: I found these little guys partying outside my house on 10 August 2006. I live in southeastern Ontario. They were in a weedy area between my concrete foundation and gravel driveway.

I looked through your beetle pages but could not find any bugs that looked similar. Are they destructive at all, or do they just like to hang out in dead foliage? Your fan,
Tracy Brinklow
P.S. Looks like I don’t truly have a reason to write after all! Just as I was about to send this email, I found the “true bug” page. So, these are milkweed bugs or box elder bugs, then?

Hi Tracy,
These are Eastern Boxelder Bugs, Boisea trivittata, and your photo is the first of the season. We can now expect a great proportion of our emails will be regarding the identification of this species which forms large aggregations on the sunny sides of buildings as the weather cools.

Letter 10 – Thousands of Yucky Bugs!!!

yucky bugs
Surely you can help!?!
There are about 2000 of these living on my tree. Half of them seem to have just “hatched”, half are mature. They don’t appear to be harming anything, just hanging out, migrating from the tree to the lawn and back again . Do you know what they are? Cause for concern?
Don and Elke (and Anna now too)

Dear Don, Elke and Anna
Your insect is a box elder bug (Leptocoris trivittatus) which is known to live in colonies of both adults which have wings and the nymph stage which is wingless. We at What’s That Bug? have gotten questions about this garden pest in the past. Here is an excerpt from a recent reply which should also apply to your situation.

On it says, “When present in large enough numbers Box Elder Bugs can do damage to Manitoba Maple trees. Most people call us in the fall because they are curious about the large numbers on the walls of their houses or concerned about the numbers that are getting in the houses.

Washing them off the walls of the house with a blast of cold water from a hose may help. The only way to ensure that they do not get inside the house is to fill in all cracks where they could be getting in, a rather daunting and expensive task.”


  • 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.

    View all posts
  • 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.

    View all posts

11 thoughts on “Boxelder Bug: All You Need to Know in a Nutshell”

  1. Eastern Boxelder Bugs – we got an invasion in our backyard when we bought mulch a few years ago. These things are everywhere out there. It’s great to finally know what they are!!!! Now how do I get rid of them??? Anyone know?

    • We had humongous boxelder tree that was cut down in our neighborhood and now we have been infested with boxelder bugs. Is there anyway for us to get rid of them.

  2. We have a similar infestation…brick frontage on house, unseasonably warm weather with sunshine. You mention 1/8 cup Dawn to a sprayer. What size sprayer so I know how much water to use. Thanks for ANY information.

  3. Hello, I though I’d add my 2 cents on this one. I’m fairly certain that the stinkbug is one from the genus Apateticus,. Though I can’t be 100% sure of the species, I believe it is lineolatus based on the species description, but as far as I can tell it shouldn’t be that far north! Here’s a link to a nice revision of the genus if you’re interested. (

  4. Kind of looks like the Heather Shieldbug (Rhacognathus punctatus), which is a European species (not unheard of in the States, and is predatory.


Leave a Comment