How to Kill, Control & Prevent Boxelder Bugs

Boxelder bugs get their common name because they are often found on boxelder trees. They are native to the western U.S. but can be found throughout the United States or wherever boxelder trees are found. They become a nuisance when they congregate on or enter homes, sheds, and garages in the fall and when they emerge in the spring.

What do boxelder bugs look like?

Boxelder bugs are black with reddish or orange markings on their wings and along their protonums, or area between their head and body. These pests look like a somewhat flattened, elongated oval and are about ½-inch long. The nymphs, or immature boxelder bugs, look similar to adults, but lack wings and are bright red in color.

What do boxelder bugs eat?

Boxelder bugs get their name from one of their favorite food sources: the boxelder tree. In the early spring, boxelder bugs feed on fallen boxelder seeds. Once the leaves start to open, they move on to the female boxelder trees or other maple trees to feed on the newly developing leaves. They have also been known to occasionally feed on the fruits of plum, apples, pear, peach, and cherry trees and even on grapes.

Why Boxelder Bugs Come Inside Your House in Fall

In the fall, boxelder bugs are frequently seen congregating in warm spots like the southside of rocks, trees, and buildings where the sun hits. Once a large mass has gathered, they will then try to migrate to nearby buildings like homes, sheds, and garages to overwinter. If they can get inside, you'll find them hiding in cracks and crevices in the walls to protect themselves from winter temperatures.

Once the temperatures cool down, boxelder bugs shelter in place until it warms up again. That means you may not notice a fall infestation until springtime when suddenly, you've got dozens of boxelder bugs trying to make their way back outside for feeding time.

Boxelder bugs are primarily nothing more than a giant nuisance when they invade your home. However, their fecal matter can cause reddish stains on curtains, drapes, clothing, and other materials. When handled or crushed, boxelder bugs can produce a strong, foul odor. They are not known to bite, but their mouthparts can puncture skin, causing a slightly irritating red spot similar to a mosquito bite.

Keep Boxelder Bugs Out

The best way to keep with boxelder bugs outside your home is to prevent them. Start in the early summer by treating boxelder, maple, and other host trees with Ortho® Home Defense® Insect Killer for Lawn & Landscape, following label directions. This will make your landscape less attractive to boxelder bugs and, by extension, your home.

To keep boxelder bugs from invading your home in the fall, repair holes in window and door screens, seal cracks and crevices around the outside of your home, and install door sweeps on all exterior doors. Then apply Ortho® Home Defense® Insect Killer for Indoor & Perimeter around your home's foundation as well as indoors around door and window casings and along baseboards. This creates a barrier that keeps all sorts of pesky bugs—including boxelder bugs—outside. Always read and follow label instructions.

Control Boxelder Bugs that Come Inside

To kill boxelder bugs you find in your house, spray them with Ortho® Home Defense® Insect Killer for Indoor & Perimeter following label directions. Then, remove the dead bugs since they may attract carpet beetles, another unwanted guest that eats dead bugs but then goes on to attack fabrics, stored dry goods, and other natural products in your home. If you can find where the boxelder bugs are gaining access to the living areas of your home, seal the opening to prevent them from crawling in. You can also choose to suck them up with a vacuum cleaner, and then immediately remove and seal the vacuum bag in a plastic bag before disposal to prevent them from escaping.

Boxelder bugs may only be a mild nuisance, but that doesn't mean you want to leave the welcome sign on your home for these bugs. Plus, preventing boxelder bugs will also help prevent other fall nuisance bugs like Asian lady beetles and stink bugs. Keep these bugs out, and you'll be nice and cozy during winter—without worrying about unwanted guests in the spring.