How to Get Rid of Boxelder Bugs

What Are Boxelder Bugs?

Boxelder bugs (Boisea trivittata) are black or dark brown nuisance insects with orange or red markings. They can become a problem if large numbers enter homes and other buildings.

Adults are about a half-inch long with flattened, oval-shaped bodies, six legs, two antennae and wings that overlap on their backs and form an "X." They're sometimes called box bugs, maple bugs or box beetles, but they're not true beetles.

Native to North America, boxelder bugs take their name from their primary host, the boxelder (Acer negundo), a type of maple tree. Also called ashleaf maples, boxelder trees grow fast and are common in urban areas where they tolerate pollution and help control erosion. Boxelder bugs can also be found on silver maples (A. saccharinum) and trident maples (A. buergerianum). The bugs feed on the juices of these trees and lay their eggs on them.

Are Boxelder Bugs Harmful to Humans?

"Boxelder bugs don't pose a threat to plants or people" and aren't a serious threat to gardens or lawns, says Ben Hottel, an entomologist for Orkin, a pest control company. The bugs don't sting or spread disease, but they do have sucking, piercing mouth parts that can puncture skin if they're trying to defend themselves. This can cause mild irritation and leave a red spot. Reports of these small, mosquito-like "bites" are rare, according to the National Pesticide Information Center.

Can Boxelder Bugs Damage Property?

Boxelder bugs can cause slight damage to host trees, Ben says, because they extract their juices, but they're primarily nuisance pests. Like their stink bug relatives, they can release a bad odor if they're crushed, so don't step on or squish them, and their fecal matter can leave reddish-orange stains on fabric.

The Boxelder Bug Life Cycle

There are three stages in the life cycle of a boxelder bug: egg, nymph and adult. The bugs emerge from winter hibernation when the weather warms up in spring. Adult females then mate and lay small clusters of rusty red, oval-shaped eggs twice a year on the leaves and in the crevices of boxelder bark.

Eggs hatch into nymphs in about 10 to 14 days. They look like adult boxelder bugs but have non-functioning wing pads (their wings develop fully later). Their bodies are a bright orange-red, and their heads are brown. Over the summer, they feed on host tree leaves, fruits and soft seeds, but again, the damage they cause is not significant. After the nymphs grow into adults, the females lay more eggs for a second generation that matures in fall. There may only be one generation each year in cool climates with short growing seasons.

When cold weather arrives, boxelder bugs look for warm, dry, sheltered places to overwinter, and they can fly long distances to find them. They enter homes and other structures through cracks and crevices in foundations and around doors, vents, decks, steps and windows. They hibernate in walls, attics, cellars and other indoor spaces, sometimes emerging into a house or building on mild, sunny days during the winter.

In the spring, boxelder bugs head back outside, about the time that buds on boxelder trees start to open. Some bugs may get trapped and remain indoors, where they eventually die. Adult bugs live for about a year. Outside, they often bask in the sun on the south and west sides of homes, trees and buildings.

How to Get Rid of Box Elder Bugs

Natural Methods to Get Rid of Boxelder Bugs Outside and Inside

Spray. Unless you have a large infestation, you may be able to get rid of boxelder bugs by spraying them with five tablespoons of Dawn or other liquid dishwashing detergent mixed with a gallon of water. A bleach and water spray will also kill them. Spray the solution directly on the bugs.

A few notes about spraying:

• If you're spraying outdoors, avoid hitting any foliage, which can be damaged.
• Don't spray indoors on any surface that could be harmed.
• If you use bleach and water, make sure you have adequate air circulation.
• If the bugs reappear, spray again as needed.

Other options: knock the bugs into a bucket of soapy water to drown them, or wash them off exterior walls and trees with a blast of water from your garden hose.

Remove hosts. Cutting down host trees, especially female or pod-bearing boxelders, is another natural control for these pests, but it won't eliminate all of them, and it's not a permanent fix. The bugs can still fly in from neighboring trees. If you don't want to remove your trees, clean up fallen seeds and leaves under and around them to eliminate hiding places. Boxelder bugs can also take shelter in piles of leaves, rocks and boards or in overgrown shrubs and other plants, so remove those. For extra protection, mow weeds and grass and rake up any debris in a 6- to 10-foot wide strip around your home.

Vacuum. Vacuuming is an effective way to get rid of boxelder bugs in your house. Dump them right away or their powerful, unpleasant smell will fill the air. Indoor bug bombs aren't a good idea because they tend to drive these pests deeper into their hiding places.

Use scents. Some essential oils, such as mint, eucalyptus and clove, and the scents of garlic, sage and lavender, are said to help deter boxelder bugs from coming inside. Mix a few drops of the oil or scent in a spray bottle filled with water and spray in areas they might enter. Don't use water or essential oils on surfaces that might be damaged.

Grow plants boxelder bugs hate. Some gardeners say that boxelder bugs hate the scent of mums, citrus plants and herbs like sage, cloves and lavender. Planting them around your foundation could deter these pests.

Use glue traps and sticky pads. These must be checked often and thrown away when they're full. Boxelder bugs are attracted to other boxelder bugs, so you might accidentally lure more if you don't discard them periodically.

Sprinkle diatomaceous earth, a fine powder made from the fossils of microalgae called diatoms, to kill these bugs. It's sold at hardware stores, some nurseries and home and garden centers. Dust it where the bugs gather and follow all label directions. You can also get it here.

Chemical Options for Boxelder Bug Control

Use chemical controls as a last resort, since chemicals can run off into storm drains and wind up in creeks, rivers, streams and other bodies of water. Natural controls like vacuuming and sealing entrances are usually just as effective, and chemicals can pose a danger to children, pets and beneficial insects like pollinators. If you must use chemicals, look for products labeled for use on boxelder bugs and follow all label directions.

Preventing Boxelder Bugs from Returning

Seal entry points. This is the best way to prevent boxelder bugs from moving inside, Ben says. "That means filling any gaps or cracks around windows and doors and checking window and door screens for tears." Also, seal areas where utilities enter your home, access points to your attic and around crawlspace vents. Look for more possible entry areas around light fixtures, air conditioning units, pipes, cover plates and conduits. Use caulk, fine-mesh screen, weatherstripping, vent covers, siding corner caps, expandable foam or chimney caps to close openings.

Clean to discourage boxelder bugs. Keep your lawn and garden free of seeds and other debris that boxelder bugs can use for shelter. Clean indoor areas with soap and water to remove their scent trail, which could attract more bugs. Spraying with equal parts of water and vinegar may help to some extent.

Call a professional. If you have a large number of boxelder bugs in your home, consider calling a professional for an inspection and to identify entry points, as well treatment plans.