Fruit and seed-bearing trees sometimes tend to attract some wanted and unwanted garden visitors. Throughout most parts of America, boxelder bugs can become quite the garden nuisance.
Boxelder bugs often appear during the Autumn and Winter months, explicitly drawn to fruit-bearing boxelder trees, maples, ash trees, and even fruit trees.
While they’re mostly harmless, not carrying common diseases and unable to bite or sting, they can become an unpleasant and unsightly issue, especially if they start to move into your home.
These bugs will usually invade in large numbers and become a nuisance during fall and, if left untreated, can cause fruit deformities and major leaf discoloration.
Are you looking to keep your home and garden boxelder bug-free? Here’s everything you need to know to identify, control and prevent boxelder bugs from invading your garden.
What are Boxelder Bugs?
Boxelder bugs, (Boisea trivittata), are a type of bug that gets its name from the trees on which they are usually found: female, seed bearing boxelder trees and in some cases, maple trees or ash trees.
These small, somewhat harmless bugs are native to the United States and Eastern Canada. They live anywhere that box elder trees are found.
- Boxelder bugs attack boxelder trees and maple trees but do not typically cause property damage.
- Boxelder bugs are not a serious threat to your safety and well-being but they can become a significant nuisance if allowed in your home.
- They seek warm areas with Southern or Western sun exposure and will hibernate for the winter.
- Once they are in your home physically removing them is the best source of pest control.
- The best time to hire professional pest exterminators is summer and fall when the majority of the bugs are not hiding in your walls.
How to Identify Boxelder Bugs
Boxelder bugs can be most easily identified by their color and markings. They have black, flat bodies with reddish/orange markings along the perimeter of their bodies near the head, as well as their wings.
When they are at rest the markings form an upside down V on their back. This upside down V disappears as soon as they open their wings and start flying, something they can do for several miles at a time.
The younger bugs, called nymphs, are roughly 1/16 of an inch long and when they first hatch they are bright red but eventually their colors convert to the red and black of adult boxelder bugs.
Are Boxelder Bugs Dangerous?
These bugs are more of a nuisance than they are a legitimate danger. They won't transmit diseases and rarely bite humans. They don't have any stingers or toxins.
That doesn't mean you won't find it disconcerting to have somewhat large insects crawling into the walls of your home and through your windows or light fixtures.
What Do Boxelder Bugs Eat?
They feed mainly on the seeds for the female box elder tree and any newly developing leaves. If you have nearby fruit trees like apple trees are plum trees, they will also consume the fruit from these trees resulting in discoloration of your foliage.
Annual Activities of the Boxelder Bugs
Boxelder bugs display a range of activities depending on the season.
Spring and Summer
You will see them emerge in the spring and spend the next few months consuming the host tree until things get cold. They will feed on boxelder trees but are typically only found on females, and they also feed on ash trees or maple trees.
A few weeks after they emerge they will begin mating. They start laying eggs on the trunks and leaves of the female boxelder trees around July. They are significantly more abundant in very hot summers followed by warm spring weather.
Summer and Autumn
Come Autumn they will congregate in any part of your home that gets direct sunlight, on warm rocks, or even sun-dappled trees. Fully grown adults will survive the winter by finding a protected area in which to hibernate.
Any building that stands taller than the surrounding area is most attractive and they will push themselves into any spaces or cracks in the home for shelter.
Winter and Spring
They hibernate in the winter but before doing so they find small crevices are cracks in your home in which to stay warm. Infestations can affect your home, your garage, or any stand-alone shed on your property.
During this time they remain generally inactive but if you maintain warm temperatures in your home an existing infestation in the walls might move into your house. If you don't remove them they will remain trapped indoors although they cannot reproduce inside your house.
Black with red/orange markings on its dorsum
½ inch | 11-14 mm
Number of Legs
Elongated/oval shaped with a flattened body and narrow head
All regions of U.S. and Canada
Boxelder bugs can be easily confused with other insects. If you are unsure whether you have a boxelder bug infestation, consider contacting a pest exterminator for professional identification.
How to Treat Boxelder Bugs
If you already have boxelder bugs in your house, the best option is to hire a pest exterminator. Simply killing them where they stand can stain all of your furniture or draperies, and killing them in the walls can leave behind dead bodies that attract beetles.
Licensed pest exterminators can remove them from the walls and prevent them from escaping and subsequently procreating. The best time to treat a box elder infestation is summer when all of the adults have left the warmth and safety of any cracks or crevices in your home.
When you meet with a pest exterminator, they can help you determine the severity of the infestation you have, locating the entry points around your home, garage, or outdoor shed.
Exterminators can put together a comprehensive treatment plan to address all entry points for you, remove the current infestation, and prevent future infestations. If you want specific pesticides used or not used, this is something to discuss with your exterminator. Good exterminators are highly flexible and able to adapt to the pest control methods you prefer.
Should you need help removing an existing box elder tree and potentially replacing it with a male iteration, qualified professional landscapers can help you safely remove and dispose of the existing tree and put a replacement in your yard.
How to Prevent Boxelder Bugs Boxelder Bugs Infestation
While they might seem harmless especially if you don't have a boxelder tree on your property, they can become particularly problematic when enough of them coalesce in one area. Large enough groups will invade your home, not just your trees.
If left to their own devices, they can occasionally puncture the skin with their mouths leaving behind slight irritation and a red spot that looks somewhat akin to the bites left by mosquitoes.
If they land on you and you crush them or squish them, you will be met with a strong and very unpleasant odor in addition to which they leave behind a reddish/orange stain. This stain actually comes from their fecal matter and it can permanently discolor your clothing.
So instead of squishing every bug you see, consider preventative measures to protect your home. Good pest control goes a long way toward preventing an infestation.
When you find them in your home you can start your pest control process by removing each bug and putting it outside or killing it outside so the staining residue does not mark your clothing.
Vacuuming any bugs you see and subsequently emptying the canister far away from your home will help alleviate larger infestations with limited effort. To kill the bugs on contact you can mix a spray bottle with two parts water and one part dish soap.
Around your home
- Repair any holes you have in your screen doors or windows. Any hole bigger than 1/2 inch will allow easy access.
- Seal any cracks or crevices using a silicone latex caulk or a high-quality silicone caulk. Again, holes that might seem inconsequential to you will be large enough for adolescent and adult boxelder bugs.
- If you don't have them, install a door sweep to every entrance you have to seal off entry points from these invaders.
- Seal all other entryways such as baseboards, windows, and door frames.
- Remove the cover plates from electrical outlets, heating ducts, air vents, and switch boxes, seal the area, and replace the cover plates.
- Remove any ceiling fans or light fixtures from their base plates, seal them, and replace the base plates.
Around the yard
- If you have Box Elder trees, seed-bearing female trees, you can remove them from your property and in so doing remove the food source for the boxelder bugs. If you want a boxelder tree in that particular location you might consider replacing it with a male tree. Boxelder bugs go for the female trees over male trees.
- If you want to maintain your female box elder tree, take measures to remove fallen seed pods from the ground directly below the tree on a regular basis.
- Remove any overgrown plants near your home, garage, or shed as well as unkempt piles of rocks or leaves as these are ideal locations for the boxelder bug to hide.
- You can also hire a bug exterminator to use low-toxicity pesticides. Fast acting products with synthetic pyrethroids can be sprayed around your home, particularly around the windows, doors, or siding to prevent infestations in your home.
Wrapping Up Our Boxelder Bugs Guide
Not sure which bugs may be bothering your garden? Take a look at some of our handy pest guides to help you.
Follow these tips, and you’ll be able to keep boxelder bugs at bay and out of your garden and home. Should you notice these pesky bugs around, It’s always a good idea to start with natural methods to keep them away.
Physical removal is always a good option; just take care when removing them not to stain your home. Keep up with regular vacuuming and garden maintenance to not provide any place for boxelder bugs to nest.
If you’ve tried all-natural methods, it may be time to consider an exterminator. Try finding a local company that uses low-toxicity pesticides to help with get rid of boxelder bugs.
About the Author
Luqman has been a pest control technician for over 20 years. He is passionate about solving people's pest and wildlife control problems through innovative, eco-friendly, and humane methods.
Luqman currently works for Pestend Pest Control Barrie. He believes that pest control is a science and feels that his function in his community is very important since he helps people live in peace without causing unnecessary harm to animals.