11 Common Questions Answered About Boxelder Bugs

How to control those little black and red pests

Boxelder Bugs
terry6970 / Getty Images

An entomologist may find the red edging of its black wings to be rather pretty, but when boxelder bugs invade your home, they can become quite a nuisance. Although this red and black bug does not cause damage, few people enjoy having large insects crawling out of cracks and onto their walls, windows, lights, or furniture.

If you have ever had boxelder bugs invade your home, you've probably sought information on their identification and control. Let's review some of the most commonly asked questions about this bug and how to control it.

How Do I Know If That Bug on My Wall Is a Boxelder Bug?

At about 1/2-inch long, boxelder bugs (Boisea trivittata) are black with three red stripes, vertical edge lines on their bodies, and red lines on the edges of its wings. These markings make it appear as though its wings form an upside-down V when they are resting with their wings lying flat.

Why Are These Large Bugs Coming Into My Home?

As their name implies, boxelder bugs are attracted to boxelder trees and also to silver maple trees. If you have these trees around your home or neighborhood, you are very likely to have boxelder bugs. In the fall, as they begin to seek shelter for the upcoming cold months of winter, they are attracted to the warm, sunny sides of homes. From there they slip between cracks and gaps in the siding or around doors and windows and often ending up inside the home during the winter.

boxelder bugs
 Illustration: © The Spruce, 2018

What Happens If I Don't Get Rid of Them?

The boxelder bugs will overwinter in the walls of the home until warmth brings them out. That warmth can be the heated air from inside your home, bringing them out of the walls into the rooms of your home during the winter months. Like bugs such as stink bugs and squash bugs, boxelder bugs can detect temperature differences of as little as one degree, so it doesn't take much for them to decide it's time to move further into a warmer environment.

Do Boxelder Bugs Bite?

The good news is that boxelders bugs do not bite or sting people or pets.

Will the Bugs Hurt Foliage?

Although they live and breed in boxelder and silver maple trees and feed on the leaves, flowers, and seed pods, they do not cause damage. Boxelder bugs in and around houseplants are generally in search of moisture. Rarely will they cause any damage to these plants, either.

Do Boxelder Bugs Cause Any Other Damage? 

They do not cause damage unless there are high populations. Boxelder bugs are primarily a nuisance pest. They only live for a few days and do not infest food or cause property damage. They do not do not breed indoors. But when a lot of them get into your home, they can be very intrusive and annoying, and their excrement can stain surfaces such as walls, furniture, and drapes.

How Do I Get Rid of Boxelder Bugs That Get Into My Home?

Once the pests get in, physical removal is best and is the only practical way to get rid of them. A few options are:

  • Use a vacuum with a long hose attachment to gather up the bugs.
  • Directly spray the bugs with a dish soap/water solution.
  • Sweep up dead bugs with a broom or vacuum.

Never squash a boxelder bug; this can stain the surface on which it is killed.

How Can I Keep the Bugs off My Home in the First Place?

A residual insecticide can be sprayed on the exterior walls of the home where you find the bugs. This is most effective in the spring or fall when the boxelder bugs are just beginning to emerge (spring) or shelter (fall). The residual will help to deter the bugs from landing, but it will not remain effective once cold weather sets in. For do-it-yourselfers, there are retail products labeled for boxelder bug control. Be sure to purchase and use only products that are specifically labeled for this pest. Read and follow all label directions and use safety equipment. 

Are There Any Non-Toxic Methods of Boxelder Bug Control?

According to the University of Wisconsin Cooperative Extension, a solution of 1/2 cup dish soap to one gallon of water can kill boxelder bugs when sprayed directly on the bugs that congregate on the exterior of your home. However, this will not have a residual effect but would need to be reapplied every time the bugs gather.

How Can I Prevent Boxelder Bugs From Coming Into My Home?

The best prevention is to inspect your home for ways these bugs (and other pests) can be getting in. Build out the bugs by screening or caulking all cracks, crevices, gaps, and openings in your home. Repair any torn or broken door or window screens, ensure doors and windows are well-sealed, and employ other exclusion techniques to reduce entry points and numbers.

Is There Any Way to Permanently Keep the Bugs Away From My Home?

The most permanent control of boxelder bugs is the removal of boxelder and silver maple trees near the home, as these are a source of food and place of breeding for the bugs when they are active during spring and summer, but this is not always practical or possible.