All About Boxelder Bugs in Utah: Facts, Habits & Effective Control
When fall arrives in Utah, so do boxelder bugs, often in alarmingly large numbers. These black-and-red beetle-like bugs get their name from the boxelder trees they feed on, and while they won’t bite or sting, they can become a major annoyance for homeowners. Boxelder bugs tend to gather en masse on warm exterior walls and sometimes slip inside houses to escape the cold. While they’re mostly harmless, nobody enjoys dozens of bugs hanging out in their living room or crawling on their siding. The good news is that with a few preventative steps, you can usually keep boxelder bugs under control. And if they’ve already invaded in force, Lawn Doctor’s Yard Armour pest control program can provide an effective solution to clear them out. Let’s explore some key facts about boxelder bugs what they are, why they invade, and how to get rid of them.
What Are Boxelder Bugs?
Boxelder bugs are black insects with distinctive reddish-orange markings on their wings and along the edges of their body. They’re about 1/2 inch long as adults (roughly the size of a sunflower seed) and have a flattened, elongated oval shape. Boxelder bugs belong to the “true bug” order (Hemiptera) and have a piercing-sucking mouthpart, which they use to feed on plant juices. As their name suggests, boxelder bugs are especially fond of boxelder trees. They feed on the seeds, leaves, and flowers of these trees, as well as other members of the maple family. In late summer and fall, you might see swarms of young boxelder bugs (which are smaller and bright red) maturing into the black and red adults. Individually, a boxelder bug is nothing to fear it’s not poisonous and it won’t damage your home. It’s only when they congregate by the hundreds that they become a bother.
Why Boxelder Bugs Invade Homes and Yards
If you’ve ever seen your south-facing walls covered in black-and-red bugs on a fall afternoon, you know how boxelder bugs got their reputation. In autumn, boxelder bugs seek warmth as the temperatures start to drop. They are most noticeable on sunny sides of buildings, you’ll often find them clustering on the south or west exterior walls, basking in the sunlight. As it gets colder, these bugs look for a cozy place to spend the winter. They often squeeze through cracks and gaps in siding, around windows, under eaves, or through door frames to get inside houses, where it’s warm enough to survive the cold months. They’ll settle into wall voids, attics, or basements to hibernate.
Come spring, the overwintering boxelder bugs that sheltered in your home will wake up and try to get back outside. This is why you might suddenly notice dozens of them appearing inside your house around February or March, sluggishly crawling on walls or gathering near windows, they’re trying to find a way back out to the trees. While boxelder bugs do not reproduce indoors or cause structural damage, their presence can be quite a nuisance. They can also stain surfaces (curtains, walls, carpets) with their droppings or if you squash them, and they emit a foul, musty odor when crushed or disturbed. Essentially, boxelder bugs invade our homes by accident while looking for winter shelter, and though they don’t want to eat our food or bite us, we end up with unwanted houseguests that are tricky to fully remove without proper control methods.
Where You’ll Find Them
You’re likely to encounter boxelder bugs in the following places:
On sunny exterior walls of homes: During cool days in late summer and fall, boxelder bugs congregate on the warmest exterior surfaces, usually the sun-facing walls of buildings. They may cover siding, brick, or windows by the hundreds as they soak up heat.
Around boxelder, maple, and ash trees: These bugs spend spring and summer feeding on trees (especially female boxelder trees that produce seeds). You might see them on the trunks, branches, and leaves, or swarming around the base of these trees.
In cracks and crevices of buildings: Boxelder bugs slip into any tiny openings they can find. This includes gaps around window frames and door frames, under loose siding, attic vents, soffits, and under roof eaves. Basically, any little crack in the exterior could be a doorway for them to get inside walls or attics.
Hiding indoors during winter: Once inside, boxelder bugs will hide out in attics, wall voids, basements, or crawl spaces to escape the cold. They remain inactive through most of the winter, then you might spot them on interior walls or ceilings as they emerge in early spring.
If you know their favorite hiding spots, you can better prepare and block their entry before they become a problem.
Problems Caused by Boxelder Bugs
Unlike more destructive pests, boxelder bugs don’t cause direct damage to structures or significant harm to plants (their feeding on trees is fairly minor). The problems they cause are mostly annoyances related to their sheer numbers:
Indoor nuisances: A few boxelder bugs inside aren’t too troublesome, but when dozens or hundreds appear in your home, it’s unsettling. They might buzz around light fixtures or crawl on walls, and dying bugs can end up littering windowsills or floors. Their droppings can leave brownish-red stains on curtains, walls, or surfaces where they’ve been hanging out.
Unpleasant odor and stains: If threatened or crushed, boxelder bugs release a smelly compound (some describe it as a pungent, unpleasant odor). This liquid can also stain fabrics and painted surfaces. So squashing a big cluster of them can result in a stinky, stained mess, not ideal!
Outdoor mess: Even if they stay outside, a mass of boxelder bugs clinging to your siding, porch, or on tree trunks can be an eyesore. They’re also hard to remove by hand. If you spray them with a hose, you’ll just end up with a bunch of dead bugs to clean up. And live ones might just scatter and regroup later.
Recurrent infestations: Boxelder bugs often return year after year to the same properties, especially if you have boxelder or maple trees nearby. Once they know of a cozy overwintering spot (like your attic or siding), they may use pheromones to attract others to the same site annually. This persistent cycle can be very frustrating if not addressed.
While boxelder bugs won’t chew wires or eat your pantry food, having swarms of any insect invading your space is something most people want to avoid. The key is to take preventative action so their numbers stay small and manageable.
DIY Tips to Prevent Boxelder Bugs
Stopping boxelder bugs from infiltrating your home is largely about exclusion and habitat reduction. Here are some effective do-it-yourself tips to keep these bugs at bay:
Seal up entry points: The most important step is to block the gaps that boxelder bugs use to get inside. Inspect the exterior of your home for any cracks, openings, or loose fittings. Use a good quality caulk to seal cracks around window frames, door frames, along the foundation, and between siding panels. Check that door sweeps and weather stripping are intact to eliminate gaps under exterior doors. Repair or replace any torn window screens or vent screens. Don’t forget openings like attic vents, make sure they are screened properly. By closing off even the tiny openings, you can prevent hordes of bugs from sneaking in when the weather cools.
Reduce their food source: If your yard has a female boxelder tree (the ones that produce all the seeds), you might consider removing it or replacing it with a different species of tree. This is a long-term strategy, as boxelder bugs are strongly attracted to their namesake tree. Of course, removing a mature tree is a big decision, but even trimming back boxelders or maples near the house can help. At minimum, rake up and dispose of fallen seeds and debris from boxelder and maple trees, as these can attract the bugs. Fewer host trees and seeds = fewer boxelder bugs breeding in your immediate area.
Spray them with soapy water: If you see a cluster of boxelder bugs on your house or porch, a simple soapy water spray can kill them on contact. Mix a few tablespoons of dish soap into a spray bottle of water and spritz it directly on groups of boxelder bugs. The soap breaks down their outer shell and they’ll quickly die. This method is inexpensive and safe for plants and pets. It’s best for small concentrations of bugs (note: it won’t prevent more from coming, but it helps eliminate the ones present).
Vacuum up the stragglers: For any boxelder bugs that have made it inside, the easiest removal method is to vacuum them up. Use a hose attachment to suck up the bugs from walls, ceilings, or window sills. Because they can smell bad when crushed, vacuuming avoids a direct smash. Be sure to empty the vacuum canister or bag immediately after, and dispose of it outside, the trapped bugs can release their odor inside the vacuum if left too long. You might even put a little soapy water in the bottom of a shop-vac canister to ensure the bugs drown and don’t crawl back out.
By combining these tactics, sealing your home’s exterior, managing the trees that attract them, and manually removing the ones you see, you can significantly cut down on the boxelder bug annoyance factor. Aim to do the sealing and yard cleanup in late summer before the bugs start swarming in fall, for best results.
Fun Facts About Boxelder Bugs
They might be pests, but boxelder bugs have some interesting qualities worth noting:
Tree lovers: As their name implies, boxelder bugs feed primarily on boxelder tree seeds, and they also enjoy other maple tree seeds. If you find swarms of them, there’s likely a maple or boxelder tree nearby.
Stinky defense: When disturbed or crushed, boxelder bugs release a smelly red liquid from their body. This is a defense mechanism to deter predators and it’s also why you’ll notice red stains if you squish them. The smell can linger, so it’s another reason to avoid smashing them if possible.
No indoor breeding: Unlike some pests, boxelder bugs do not reproduce indoors. The ones you see inside over winter all came in from outside; they aren’t laying eggs in your house. They need the spring warmth and access to their host trees outdoors to breed and complete their life cycle.
Easy to identify: Boxelder bugs are hard to mistake for anything else thanks to their bold red-orange markings. The adults have three striped lines on the area behind their head and red veins in their wings. Nymphs (young ones) are bright red with small black wing buds. Their colorful markings make them one of the more easily recognized “nuisance bugs.”
Sun seekers: Boxelder bugs absolutely love warmth. They will crowd onto warm, reflective surfaces like brick walls, light-colored siding, or even rocks that have been heated by the sun. This behavior, called aggregation, is why you see clumps of them together they’re all gathering at a hot spot to raise their body temperature.
Understanding these quirks can make boxelder bugs a little more tolerable but of course, you still don’t want them overrunning your home!
Professional Boxelder Bug Control in Utah with Lawn Doctor’s Yard Armour
If you’ve battled boxelder bugs year after year and they keep coming back in droves, it might be time to get professional help. When DIY methods aren’t enough or you’re faced with an overwhelming infestation each season, Lawn Doctor’s Yard Armour pest control program is ready to step in. Think of it as having a dedicated boxelder bug exterminator for your Utah home, one who knows exactly how to reduce those pesky populations and keep them from invading your space.
How we tackle boxelder bugs: Our Yard Armour technicians will start by inspecting your property and identifying the hot spots where boxelder bugs are congregating or entering your home. We then apply a targeted barrier treatment around the perimeter of your house. This treatment typically involves a residual insecticide spray applied to your foundation, lower siding, around windows and doors, eaves, and other entry points. The goal is to create an invisible shield that kills or repels boxelder bugs (and other invading pests) before they can slip inside. We also can treat the yard area around host trees or shrubs, reducing the horde right at its source. The products we use are professional-grade and highly effective at knocking down boxelder bugs quickly.
Yard Armour isn’t a one-time fix, it’s designed as an ongoing protection program. In Utah, boxelder bugs tend to be most active in spring (when they emerge) and especially in late summer/fall (when they swarm and seek shelter). With that in mind, we schedule our treatments at strategic times through the season. Typically, multiple visits per year are set up to coincide with when boxelder bugs start gathering and again as they look to overwinter. By reapplying the barrier periodically, we maintain a strong defense so your home stays protected all season long. And should you ever notice a big surge in bug activity between scheduled services, just let us know, we’ll return to re-treat at no extra cost, ensuring you get the results you expect.
One thing our customers appreciate is that Yard Armour treatments are focused outside, meaning we treat your problem where it starts. You usually won’t need interior sprays (we avoid bringing chemicals indoors unless absolutely necessary for a severe infestation). Keeping the treatment exterior-only not only tends to stop the bugs before they ever come inside, but it also means minimal disruption for you. The products we apply are safe once dry, so your family and pets can continue enjoying the yard as usual.
Lawn Doctor proudly provides boxelder bug control and perimeter pest services across Utah County and the Heber Valley. We serve local communities like Provo, Orem, Heber City, Springville, Spanish Fork, Payson, Santaquin, Mapleton, Midway, Salem, and the surrounding areas. As local experts, we’re familiar with the seasonal quirks of pests in our region including those swarms of boxelder bugs!
Tired of playing host to hundreds of red and black “guests” each year? Take action and protect your home. Contact Lawn Doctor today for a free quote on our Yard Armour pest control program for boxelder bugs, or call us at (385) 463-2430 to speak with a friendly expert. We’ll answer your questions and help set up a plan to defend your home. With our professional help, you can enjoy a boxelder-bug-free home and yard, and finally say goodbye to those pesky invaders each fall!
