Lots of boxelder bugs are traipsing through homes this winter to the consternation of human occupants. We reluctantly share our home with a few during cold months.
This amazingly common and crafty insect is a true bug named for common boxelder tree. You don’t have to have boxelder trees nearby to “enjoy” visits by the bug. Maples and ash trees of several species make suitable hosts. Since these trees are everywhere in suburbia it’s no wonder boxelder bugs pester so many people. The insect makes its living feeding on tree seeds and sap yet poses no threat to its host. Unlike the pests of many other trees, boxelder bugs don’t kill trees.
Come fall box elder bugs prepare for cold weather by tucking themselves into bark crevices to patiently wait out the cold. However, they would rather be warm. If a house is nearby, they seem to sense that soon the furnace will be going and indoors is the best place to overwinter.
How Boxelder Bugs Get In
Although they are fairly large insects boxelder bugs can crawl through tiny cracks and holes. Often, they swarm in the sun on the exterior of a house and some manage to find their way inside. Winter is spent idly exploring light fixtures, furniture, and walls.
They are not really a serious pest. Pesky might be a better way to describe them. Boxelder bugs neither bite nor sting. They do sometimes crawl on people and pets. Perhaps their most disagreeable characteristics are pooping and emitting a disagreeable odor if they are crushed. It’s this bad odor that protects them from predators. Hardly anything will eat a boxelder bug.
Getting Rid of Boxelder Bugs in Your Home
Want to rid the house of boxelder bugs? The best defense is a caulking gun. Late each summer seal up cracks that allow them to squeeze into the house. Look for cracks and holes around window and door frames and around wires and pipes leading into the home. Bugs discovered wandering around inside can be vacuumed up, and a shop vac can suck up hundreds sunning on the exterior. Dump them in soapy water and they’ll quickly drown. A hose can also knock them off an exterior wall. Insecticides kill them but perhaps create more problems than they solve. Some people report that spraying them with soapy water also kills them.
We’ve had some success at Winding Pathways in reducing the number of bugs we pick off walls and windows in the winter. We used to bring in a week’s worth of firewood and stack it near the woodstove. For years we didn’t realize boxelder bugs were hiding in the wood. Once they warmed up the insects set out exploring the house. Now we leave wood outside and only bring in a few pieces that go directly into the stove. It’s reduced, but not eliminated, the number of boxelder bugs inside.
Boxelder bugs aren’t harmful, but they are pesky and goofy. Caulking a home’s cracks can encourage them to winter outdoors in trees, rather than in homes. One speaker on Science Fridays quipped, “Boxelder bugs have nowhere to go and all day to get there.”