Box Elder Bugs are Back! Again!

It’s September 26 and another beautiful fall day to savor … until one ... two … fifty… several hundred box elder beetles cover the sunny side of local homes. Many Skyline residents dread this day marking the beginning of a six month long battle of co-existence with these insects. SRN receives much mail about them along with many suggested strategies to limit their population ranging a zen approach to all out chemical warfare. HORTIDEAS in its February 2005 issue, ran excerpts from “Dealing with Boxelder Bug Problems without Pesticides,” by Caroline Cox, Journal of Pesticide Reform 24 (4), Winter 2004, 6-7. Here are some facts and suggestions from this article.

Box Elder beetles are not really pests, just nuisance insects (sometimes real nuisances!). When fall approaches and temperatures drop, they may travel several miles seeking protected areas to winter. On warm winter days they come out and rest in the sun often on the south and west sides of homes. They are opportunists who can squeeze through minuscule spaces in order to winter inside warm, cozy homes. In the spring they become more active, laying eggs outside near the seeds of boxelders or other maple trees. They do not lay eggs indoors.

There are many kinds of damage that box elder beetles do not cause. They do not damage or eat our food; rather, the young insects feed on seeds and the adults feed mostly on the leaves, flowers and seeds of maples and boxelder trees. These insects do not cause much damage to ornamental landscape plants, houseplants, and only rarely cause significant damage to fruit trees. They do not injure pets, livestock, or people. And they do not cause structural damage to buildings and furniture. About their worst habit is excreting; this leaves “bug stains” on curtains, walls, furniture, windows, and clothing.

If box elders beetles find a way into your home, explore how they do this and try to eliminate this entry. Repair windows and screens that are torn. Caulk cracks around windows, doors, vents, light fixtures, pipes, and air conditioners. Attach weather-stripping around doors and windows. Keep lights off at night near doors that may be opened since box elder beetles are attracted to light. Rake leaves and remove unnecessary weeds and grass adjacent to your home, especially on the south and west sides. Sweep up maple and boxelder leaves around your home, on decks, on patios, and in the driveway.

The article lists three methods for removing box elder bugs from inside your home: collect them by hand (ah!), sweep them, and vacuum them. Smashing them against the wall or on furniture will probably kill them, but in doing so causes a stain and produces an odor. If you find them on exterior walls or on tree trunks, try using a strong stream of water to wash them off and drown them. Most experts agree that chemical controls are largely ineffective and unwarranted for this nuisance pest. Insecticides are generally not recommended. Insecticides are often no more effective than vacuuming or hosing.

(Editor’s Note: If you are planning on selling a home that attracts box elder beetles, you have from April 5 to September 26 to make a sale!)