Boxelder Bugs: What to Know

Medically Reviewed by Jabeen Begum, MD on January 13, 2023
6 min read

All sorts of pests are capable of invading your home throughout the year. But some of them are more problematic than others. Insects like boxelder bugs are more of a nuisance pest than a burden on your health or finances. 

Make sure that you’re familiar with these bugs so you know what to expect and how to manage them if you see them in or on your building.

Boxelder bugs are a type of insect in the Rhopalidae family, which also includes stinkbugs and cicadas. Technically, this family is known as the scentless bug group. But both boxelder bugs and stinkbugs release bad smells when they’re pressed or squished. 

Some people think of boxelder bugs as nuisance pests. They’re not considered commercial pests. They’re mainly a nuisance in the fall when they invade homes while looking for places to hibernate. 

Learn their habits and physical characteristics so you can positively identify these pests.  

What does a boxelder bug look like? 

Boxelder bugs have flat, elongated bodies that are brownish-black in color. Their wings fold over one another to form an X on their backs. They have red markings on the edges of their forewings and on portions of their heads. They also have red eyes and reddish-orange tips on their long legs. 

Males are typically smaller than females. Adults range from 0.39 inches to 0.55 inches in length. 

What’s the boxelder bug life cycle? 

There are three stages to the boxelder bug life cycle: 

  • Egg
  • Nymph — this includes multiple instar stages
  • Adult

Only their adult forms can become problematic pests

The nymphs are an average of one-sixteenth of an inch long and start out entirely red. Their bodies darken as they age. They don’t form wings until the later instar stages of their nymph forms. 

On average, a boxelder bug lives for one year. Luckily, they only last a few days when they wake up in the middle of winter and wander about your home. 

What does a boxelder bug eat? 

For the most part, boxelder bugs eat parts of the trees where they live. This includes the leaves, flowers, and bark of a variety of trees, including: 

  • Boxelder
  • Maple
  • Ash

They also feed on a variety of fruit — from apples to peaches.

There are two main species of boxelder bugs. They have similar behaviors and physical characteristics. This means that you can manage both species in the same way. 

Boisea trivittata. This species is simply known as the boxelder bug. They originated in western and southwestern parts of the U.S. but have since spread throughout the country as well as into Mexico, southern Canada, and Guatemala.  

Boisea rubrolineata. This species is known as the western boxelder bug. It’s native to the west coast of North America — from British Columbia through Southern California and as far east as New Mexico and Idaho. You currently won’t find this species outside of its native range. The main way to tell these ones apart from B. trivittata is by the additional red-orange markings on their forewings. The markings on this species line the edges of the wings and trace the internal venation patterns. 

You can find at least one boxelder bug species in all parts of the U.S. They prefer areas with deciduous and mixed forests or open meadows.

During the spring, summer, and early fall you can find these bugs living on the trees that they use for food. 

In late fall, when the temperature cools, the bugs start to cluster on the sunny southwestern sides of buildings. You’ll likely find them hunting for crevices in your foundation as well as cracks in doorways and window frames. They need to find warmth so they can hibernate throughout the winter.

The main sign that you have a problem with boxelder bugs is when you see actual adults inside your house. If you find one of them then you know that there are plenty more of them clustered somewhere nearby. This will likely be near an entrance to your home — like a crack in your foundation or around the edges of a low-level window.  

You may also notice some brown staining from their feces on pale surfaces in your house. This could include your: 

  • Walls
  • Carpet
  • Curtains
  • Painted windowsills

Boxelder bugs are around throughout the spring and summer months, but you likely won’t notice them until late fall. This is when they start to look for places to hibernate and end up clustering around the lower edges of buildings. 

Boxelder bugs aren’t considered a serious threat to your health or home. Rare reports state that they are capable of biting humans. But this shouldn’t cause any significant damage or require any kind of treatment. They don’t carry any human diseases

The only damage that they do to your property is in the form of brownish stains left behind by their feces. When they feed on fruit trees, they do very little damage to the fruits — just some puckering and other types of surface-level disfigurement. 

Another slight problem is that they smell bad when you squish them. Be prepared to handle the bad smell when you’re eliminating them.

If you’re bitten by a boxelder bug, carefully monitor your bite. Get medical attention if it seems at all serious. Otherwise, there aren’t any human health problems associated with these insects.  

If you have a problem with boxelder bugs for one season, there’s no guarantee that they’ll be back the next year. This means that you don’t need to take any preventive measures in the spring. Instead, you should only prepare to handle these insects in the fall. If you want to keep them out of your house, you should: 

  • Seal up all cracks in your foundation
  • Seal areas where cords and vents enter your house
  • Replace broken door and window screens
  • Install rubber sweeps on exterior doors

You can also spray the external walls of your home with a pesticide that’s approved for this type of application. The problem is that most pesticides that are safe for use on your external walls aren’t very effective against boxelder bugs. 

If you do want to try this method, then always select your pesticide with care and follow the instructions perfectly. Otherwise, you risk endangering your own health and that of your children and pets. 

Some sources say that you can eliminate the trees where they live to deal with your bug problem. But boxelder bugs can fly for miles to find food and shelter. Cutting down trees will ultimately do more harm than good for the environment as a whole.  

Once boxelder bugs are in your house, your best bet is to physically remove them. You can vacuum them up or sweep them up with a broom and dustpan. Check near houseplants for additional bugs — they like to look there for water. 

You can also directly spray individuals with a mixture of detergent and water or other common household cleaners. This is an effective way to kill individuals without endangering your health or your pets’ health. Just make sure to read any warnings or hazards on your instruction labels before spraying particular fabrics. 

You can always call a professional pest removal service if your infestation is too extreme. In general, boxelder bugs are much more of a nuisance than an actual threat. The best way to handle them ultimately depends on how annoying you find them to be.