Box elder Bugs
Some insects are pests because they bite, sting, carry diseases, or damage food that we want to eat. Other insects are not really pests, just nuisances. The box elder bug is a good example of a nuisance insect. If you’re tempted to reach for a spray can because there are lots of box elder bugs flying around your house, remember that some straightforward pesticide-free steps can encourage them not to congregate in or around your home.
Identifying Box elder Bugs
Box elder bugs are brownish-black and about 1/2 inch long. They have three red lines just behind their head. Their abdomen is also bright red. Young box elder bugs are mostly red and more oval than the adults.
There are two kinds of box elder bugs in the U.S. The western one is found west of Nevada, while the other species is found in the East.
Recommendations for managing both kinds of box elder bugs are the same, so you don’t need to try to figure out which kind is in your yard.
The western box elder bug is less of a nuisance than the eastern one.
Life History and Habits
Box elder bugs spend the winter in protected places, including homes. On warm days, they will come out and rest in the sun, and you’ll see them on the south and west sides of your house. They do not breed indoors.
In the spring they become active outdoors, and lay their eggs near the seeds of box elders or other maple trees. The immature bugs feed mostly on these seeds, and the adults feed mostly on the leaves, flowers and seeds. There are usually two generations during the summer.
After the first frost in the fall, adults move to their winter shelter. They can travel several miles looking for winter shelter.
What Kinds of Damage Do Box elder Bugs Cause?
There are many kinds of damage that box elder bugs do not cause. They do not cause much damage to ornamental landscape plants, and rarely cause significant damage to fruit trees. They do not injure people or pets. They will not feed on house plants or on your furniture. They don’t cause structural damage to your home.
However, box elder bug excrement can stain curtains, furniture, or clothing, and they give off an offensive odor when they’re crushed.
Keeping Box elder Bugs Out
If box elder bugs are a problem inside your house, you should make it hard for them to find a way to get inside. Repair window or door screens that are torn. You should also screen crawl space openings, vents, and louvers. Caulk cracks around windows, doors, vents, light fixtures, pipes, conduits, and air conditioners. Attaching weather-stripping or “sweep strips” to the bottom of your doors will help too. If this all sounds like a lot of work, remember that you’ll also be keeping other pest insects out of your house as well. Box elder bugs are attracted to light, so don’t leave doors or windows open when your lights are on.
Make Your House Unattractive to Box elder Bugs
To Box elder bugs often like to spend the winter under rocks, boards, and other debris; in cracks and crevices in walls; in casings around windows and doors; in and around building foundations; and inside houses. They seem to particularly like rough surfaces, two-story houses, and houses close to large trees. Here’s how you can make your house less inviting:
- Move any piles of rocks, boards, leaves, or general debris that are near your house.
- Rake leaves and remove unnecessary weeds and grass from a strip between six and ten feet wide around your foundation. If you don’t want to do this all the way around your house, focus on the south and west sides.
- Sweep or vacuum up box elder and maple seeds. A shop vacuum works well on driveways and patios. It can also pick up seeds from your lawn.
- Don’t plant female box elder trees near your house. You can plant male trees, as they are not attractive to box elder bugs. Remember that because of the distances box elder bugs can fly, your neighbors’ trees may be the source of your problem. Some towns have ordinances prohibiting planting these trees. You can also consider removing existing trees, if your problem warrants it.
Getting Rid of Box elder Bugs inside Your House
Three methods are recommended for removing box elder bugs from your house: hand collecting, sweeping, and vacuuming. If you collect them by hand, you can toss them outside. Box elder bugs can also be drowned.
Be gentle, suggests University of Idaho extension entomologist Bob Stoltz; “if you mash them, they could stain the wall or carpet red.”
Getting Rid of Box elder Bugs in Your Yard
If you find box elder bugs on walls or tree trunks and want to get rid of them, try using your garden hose. A forceful stream of water will wash them off and drown them.
You can also use boiling water to kill clusters of box elder bugs. Remember boiling water can kill grass in your lawn or other desirable plants, so you need to be careful when you’re using this technique.
Using Pesticides to Kill Box elder Bugs
“Chemical controls are largely ineffective and unwarranted for this nuisance pest.
