Boxelder Bugs in Michigan Homes

Boxelder bugs are black and red-orange insects, about half an inch long, that gather on sunny walls in September and October and then crawl into homes to spend the winter. They do not damage wood or wiring, and they do not breed indoors. They can still arrive by the hundreds and stain curtains and walls, so the best time to stop them is before they get inside.

How to Identify a Boxelder Bug

An adult boxelder bug has a flat, narrow, oval body that is mostly black. Three red or orange lines run down the area just behind the head, and the edges of the wings carry the same color. Young boxelder bugs, called nymphs, are smaller and bright red, and you will often see them mixed in with the adults on the same tree or wall.

Boxelder bugs are true bugs. They feed by piercing seeds and plant tissue with a beak-like mouth, mostly on the seeds of boxelder trees, a type of maple. They sometimes feed on other maples as well. Homes close to seed-bearing boxelder trees usually see the largest numbers.

Why Boxelder Bugs Move Indoors in Fall

As days get shorter and nights turn cool, adult boxelder bugs look for a protected place to wait out the winter. They gather on the south and west sides of buildings, where siding and brick hold the afternoon heat. From there they work into gaps around windows, door frames, siding, soffits and utility lines, and settle into wall voids and attics. They stay inactive through the cold months, then wake on warm days and wander toward light and heat, which is why many Michigan homeowners first notice them on a sunny window in February or March.

Signs of a Boxelder Bug Problem

How to Keep Boxelder Bugs Out

1. Seal before September. Caulk gaps around window and door frames, siding joints, fascia boards, and the spots where pipes, cables and vents pass through the wall.
2. Check every screen. Repair torn window screens and make sure attic, soffit and roof vents are screened.
3. Close the bottom of doors. Add or replace door sweeps and garage door seals so light does not show underneath.
4. Vacuum, do not crush. Indoors, vacuum boxelder bugs instead of swatting them, which can leave a stain. Empty the vacuum outside afterward.
5. Knock down outdoor clusters. A spray of dish soap and water kills the bugs it touches on outside walls, though it will not stop new ones from arriving.

For the full fall routine that covers mice, stink bugs and spiders as well, use the fall pest-proofing checklist for Michigan homes.

How BTR Handles Boxelder Bugs

Boxelder bugs are one of the pests BTR's General Pest Control service is designed to prevent. The service can be booked for the interior, the exterior, or both. A visit starts with an inspection to find entry points and the places bugs are gathering, followed by a perimeter treatment outside and targeted applications in cracks and crevices inside where needed.

BTR uses EPA-approved products and never treats pollinating plants, to help protect bees and butterflies. Homeowners who want coverage across the year can ask about the Seasonal Package, which includes three visits. Ask which warranty terms apply to your service when you book, and see the warranty page for the published terms.

Boxelder Bug Questions and Answers

More Fall Pest Help

• Brown marmorated stink bugs, which invade the same walls in the same weeks
• Spider control for the fall spider season
• How to keep mice out of a Michigan home
• Fall pest control in Michigan and the Michigan seasonal pest calendar

BTR Pest Control is based in Livonia and serves homes and businesses in Wayne, Oakland, Washtenaw, Macomb and Livingston Counties, Michigan. See all areas BTR serves.