Black and orange insects abound this time of year. I have had several calls about the black, orange striped boxelder bug.
As the weather gets cooler, these bugs start to leave trees in which they have spent the summer feeding, in search of a protected winter home. Unlike ladybugs, surface color doesn't seem to make a difference to boxelder bugs. Instead, they like warm areas, and seem to be attracted to southern or western sides of buildings. Once cold weather has set in, these pests work their way into our homes; inside walls or attics. Although these insects are usually inactive during winter months, mild sunny days might lead them to sunny windows and warm spots.
Boxelder bugs do not lay eggs or feed indoors, and are harmless, as they do not damage your house, furnishings or family members. However, they can be a nuisance due to the sheer numbers in which they appear.
The most effective deterrence against boxelder bugs is to prevent their entry by sealing cracks and gaps that allow them access to your home. Using a lawn and garden insecticide or soapy water on outside masses of bugs will also help to reduce the number that get in. Remove wood piles, garden debris and leaf piles from around the foundation of your home to eliminate any potential boxelder bug habitat.
Once these bugs have made their way inside, household insecticides are ineffective. Remove these bugs with your vacuum cleaner as you would for the Asian lady beetle.
Boxelder bugs live, feed and breed on female boxelder trees; those that produce seed pods. It has been suggested removing these trees will reduce boxelder bug populations, but I would recommend against it. Spraying or removing female trees is not a practical solution. Boxelder bugs can fly up to a couple of miles from their food source, and boxelder trees are common in our area.
Boxelder bugs are not a serious problem every year. They are most prolific during dry, warm years. Our cooler-than-normal summer might mean we won't see too many this fall. Let's keep our fingers crossed!
Here's wishing you luck in defeating your worst bug invasions. Until next time, happy gardening!