800-937-8398 Call us for a free quote Contact us

If you ever see red and black bugs and wonder what exactly they are, you’re in the right place. There's a good chance the creatures you are encountering are boxelder bugs. We are here to teach you about these bugs and what you should do about them.

In the case that you’re worried about boxelder bugs showing up around your home or business, contact Western Exterminator online or call us at 800-937-8398 today to discuss an effective solution.


Western boxelder bug

Boxelder bugs may become a nuisance pest in your home during the autumn. The adult western boxelder bug, or boisea rubrolineata, is gray-brown to black in color and has red lines on the part between its neck and abdomen, as well as red lines on the wings. It is ⅜ to ⅝ inches in length. The western boxelder bug is a different species than than the boxelder bug Boisea trivittata (which is located in the eastern United States to eastern Nevada).

Be careful when trying to identify a boxelder bug, as it can look like other creatures. You may think a small milkweed bug (lygaeus kalmii) is a boxelder bug, but the small milkweed bug has an X shape on its body.

Western boxelder bugs are located in ArizonaNevada, Texas, the states on the Pacific coast, and British Columbia. Western boxelder bugs feed on the female boxelder tree (Acer negundo) - which is located in eastern Oregon, southeastern Washington and eastern California - and can also get nourishment from maple trees. Boxelder bugs favor feeding on seeds although they can also consume sap.

Eggs are laid by female western boxelder bugs in the cracks of tree bark during spring. The eggs are a red color and take 10 to 14 days to hatch. Nymphs are colored bright red but gain dark marks as they grow. Take note: adult western boxelder bugs have a dark-orange body under their wings, so you may see that as they fly.

You are more likely to observe western boxelder bugs during the fall, as they will enter homes to pass the winter. They will then re-emerge in spring when it becomes warm.

Boxelder bug behavior and habitat

During the winter months, individuals or small parties of boxelder bugs enter homes and fly into windows, bathtubs, and sinks, congregating on the floor adjacent to their overwintering harborage. Boxelder bugs can be annoying and may spot curtains, furnishings, and clothing with their excrement. When crushed, they give off an offensive odor. If trapped in basements or houses, they will eventually die.

In the fall, adult boxelder bugs assemble on the south sides of trees, rocks, and buildings to warm themselves in the sun. After large masses of bugs accumulate, they tend to fly to nearby buildings or other protected sites where they hibernate for the winter. They will enter homes and buildings and hibernate within the walls of the structure. Boxelder bugs do not reproduce inside homes but enter through windows, doors, ceiling lights, soffit and dryer vents, outdoor faucets, and on the siding of a home.

Do boxelder bugs bite?

Although boxelder bugs are not typically recognized as biters, they do have the ability to pierce into skin, which makes the skin a bit irritated and results in a red spot that’s akin to a mosquito bite. Do get medical attention if you happen to be bitten and experience any kind of severe reaction. These bugs do not sting and are not known to cause damage to homes, however, their feces can stain light-colored surfaces.

How to get rid of boxelder bugs

You can vacuum to remove boxelder bugs. Also, you may want to get rid of seeds that are under host trees to cut out a source of food - or get rid of female boxelder trees that are close to your property. To help deter adult boxelder bugs from coming inside to spend the winter, fix torn screens on doors and apply caulk to cracks that are around windows and doors.

Although boxelder bugs will likely not cause any major damage to your property, they may be a bother. Contact Western Exterminator to determine what to do if you’re finding a lot of boxelder bugs around your home or business.

Other red and black bugs

Though the following bugs may look a bit similar in color to boxelder bugs, they are not the same creatures. Watch out when trying to pinpoint what kind of bug you’re seeing.

Small milkweed bug

These bugs are known as lygaeus kalmii and are dark gray to black in color with an orange or red band on the front wings (it looks like an X). The head is black and has a red spot. They turn to milkweed and other plants for nourishment. They can also consume fluids of insects that have died as well as monarch caterpillars and pupae.

Small milkweed bugs lay their eggs on milkweed when it is springtime and can have more than one generation in a year. The eggs are laid very soon after they become adults and turn from yellow to close to red when it gets close to time to hatch. You likely won’t need to take control measures for milkweed bugs, but reach out to Western Exterminator if they do become a problem.

Red-shouldered bug

As the name suggests, red-shouldered bugs (jadera haematoloma) usually have a bit of reddish color on their shoulders, and their eyes are reddish as well. They are located in the southern U.S. The rest of the upper side of the body can be from dark gray to black. Nymphs are more red (the other parts of the body are brown).

Red-shouldered bugs like feeding on goldenrain trees and chinaberry trees. They do not cause much harm to host plants. You can use water to remove them. But as always, if they create an issue around your property, get in touch with Western Exterminator to figure out how to manage the issue.

Find your local branch

We were unable to access your location. Adjust your browser settings or enter your place or zip code above

Mr. Little's blog

See what the hot pest topics are in Mr. Little’s world.