Houston Pest Guide: Boxelder Bugs

Boxelder bugs are the small black and orange bugs that will swarm indoors during cooler weather. While they typically do little damage, having thousands of little bugs flying around your home is no fun. Prevention is the best way to keep these pests out of your home.

Boxelder bugs are dark brown to black in color, with distinctive reddish-orange markings on their thorax and wings. These bugs can grow up to 1/2 an inch in length. They primarily feed on the buds of boxelder trees, hence their name, but will also feed on maple and ash trees. Boxelder bugs are not a threat to human health, but they can become a pest because of the damage they do to plants and their tendency to swarm inside homes.

Why Do Boxelder Bugs Swarm in Houses?

Boxelder bugs swarm in houses because they are seeking warmth. Boxelder bugs are sensitive to cold and will seek warm shelter when the weather starts to turn colder. They swarm together in large groups, seeking tight, protected warm spaces to shelter over the winter. Your house has many such spaces that can be very attractive to boxelder bugs. Boxelder bugs can gain access to empty spaces inside of walls or roofs through very small cracks, coming together in large colonies and intending to hibernate for the winter.

But when they do seek shelter inside of homes, the biological clocks of boxelder bugs can be disrupted. Turning the heat on inside the home can be enough to fool their bodies into believing that spring has come again, and cause the swarm to emerge. Unfortunately they also instinctually head towards the heat when they wake up, meaning you can wake up to find groggy boxelder bugs covering your walls and ceiling.

Houston’s short winters mean boxelder bugs are usually only a problem in the city only in October through February.

Why Are There So Many of Them?

Boxelder bugs move in swarms. They hibernate over the winter in sheltered areas, then emerge in the spring to feed for several weeks before mating and laying eggs. After the eggs hatch, the young boxelder bugs grow to maturity, the older bugs die off, and the swarm seeks shelter for the next winter, and then next spring the cycle repeats.

Are Boxelder Bugs Harmful?

While boxelder bugs aren't considered a serious agricultural or garden pest, they can do damage to young buds on fruit trees and cause the fruit to grow misshapen and distorted. The one plant they will do the most damage to is boxelder trees, which are their preferred food source. That's why they're called boxelder bugs. If swarms in your home are a persistent problem, consider removing any boxelder trees around your property.

How Can I Keep Boxelder Bugs Out Of My home?

Making sure that your house is free of cracks and well-sealed can help reduce the chances of boxelder bugs entering your home. Boxelder bugs are especially likely to enter the home through gaps in windows and doors, so check to make sure that all window and door seals are tight, and that there no holes in window screens.

It’s also important to make sure that access to any hollow spaces inside of roofs or walls is kept well-sealed from the outside. If you’re concerned about preventing boxelder bugs from entering your home, check that all the seals around eaves and under the roof are tight, and that any attic vents are tightly screened.

If you notice a large number of boxelder bugs around your house during the summer, it can also be a good idea to contact a pest control company to apply a preventative treatment around the house to keep boxelder bugs out. Spraying under the eaves and around doors and windows in mid to late August can help prevent these pests from coming in to your home.

What Do I Do if There are Boxelder Bugs are Swarming in my Home?

Call us at 713-222-PEST (7378) . While boxelder bugs are not harmful and don’t generally cause damage, having the walls and ceiling of your home covered with small black and orange bugs is far from pleasant. The pest control professionals at Bulls Eye can help you get those boxelder bugs out of your home, and take the appropriate steps to make sure they don’t come back again.