Boxelder Bugs – Central Oregon’s Nuisance Pest

The boxelder bug (Boisea trivittata) is an insect that is usually found around female box elder trees, as well as maple and ash trees. They are about ½ inch long, black with orange or red markings. The young bugs are smaller and bright red. They will often form large clusters while sunning themselves in areas near their host plant, such as on building exteriors or large rocks. Many of our customers find them clustering on the warm and sunny southern and western sides of their homes.

During the spring and summer, boxelder bugs feed and reproduce on female (seed-bearing) box elder trees. In the winter, they seek shelter in tree stumps, under debris, or within home walls. In Central Oregon, they can winter in pine trees, so you may see them at times on a sunny spot of a pine tree trunk. With large infestations, you may find boxelder bugs entering your home through open doors, windows and cracks.

boxelder bug central oregon

Adult and young boxelder bugs.

While finding large clusters of these bugs may be alarming, boxelder bugs are what we call “nuisance pests”, meaning they don’t do any damage, but are just a plain nuisance. They do not sting, bite or transmit disease and they are not known to cause damage to homes or damage to plants. However, their “droppings” can stain colored surfaces and they can release an unpleasant odor when squished.

Chemical control of boxelder bugs is difficult because large nymphs and adults are tolerant of insecticides. Also, insecticides that can be used on building exteriors are typically not rated to rid of these insects.

We advocate for minimal use of insecticides when caring for trees. Keep in mind the following if you have box elder bugs on your property:

  • Washing (and drowning) boxelder bugs off of the exterior of your home can be a good way to rid of them.
  • If box elder bugs are in your home, the best way to get rid of them is to vacuum them up and seal and dispose the bag.
  • Boxelder bugs do not reproduce inside your home, but find their way inside through windows, doors, ceiling lights, soffit and dryer vents, outdoor faucets and along cracks in siding. Consider sealing, caulking and weather-stripping any cracks or crevices in your home. You also get the added bonus of creating a more energy efficient home!
  • Reconsider having wood stacks, leaf and rock piles and overgrown plants—all of which can harbor boxelder bugs.
  • If you don’t want to remove a female box elder tree, try keeping the ground below free of fallen seedpods.
  • Removal of a female box elder will ensure that you get rid of them. If you do remove the female tree, consider planting another tree in its place!

Contact us to learn more about box elders and box elder bugs! Email us or call 541-480-4223.

–Mike D.