Boxelder bugs or 'Democrats' are a very familiar sight in the fall when they congregate on the sunny sides of homes to warm themselves. Boxelder bugs are plant-feeding insects, although they rarely cause significant enough damage on plants to warrant control. In the fall when they are seeking overwintering sites boxelder bugs often enter buildings through small openings around windows, doors, conduits, and pipes and through small cracks in or above the foundation. At times, large numbers can be seen on home foundations seeking entrance. Inside the home, boxelder bugs do not bite humans or pets, or infest food or other household items, but are simply a nuisance and may stain curtains or walls.
The primary outdoor host plant of the boxelder bug is the female boxelder tree where they feed by sucking plant juices from the leaves. Boxelder bugs have also been observed on male boxelder, ash, maple and occasionally on strawberries, grasses and various other plants. Adult boxelder bugs are dark gray with three red lines behind their head and three red lines on their wings. The adults emerge in spring and lay small, red eggs on their favored host plants. Nymphs are similar to the adults in appearance and shape, being bright red with small, dark colored, oval shaped wing pads on their back and black legs.
Prevention is the most permanent strategy for controlling boxelder bugs around your home. This fall before night temperatures start getting cool, seal or caulk all openings around chimneys, windows and doors or in walls, siding or foundations that the insects can use to enter your home. Eliminate gaps at the bottom of outside doors by attaching sweeps. Added benefits to this weatherproofing of your home will be lower heating bills this winter and the exclusion of other insects, such as spiders and Asian lady beetles!
Outside the home, boxelder bugs are primarily a nuisance pest annoying residents by congregating, sometimes in very large numbers, on the warm sides of their homes during bright fall days. Chemical control of adults is often not desirable, since multiple applications of insecticide are required. Keep in mind that adult boxelder bugs are good fliers and new groups of insects can quickly fly in from a considerable distance to take the place of those killed by insecticides. Non-chemical alternatives include insecticidal soap and a homemade solution of hot, soapy water. Although these non-chemical techniques also require multiple applications, they are effective at killing adult insects sprayed with the soap solution and much safer for repeated use around children and pets. The best method of control once insects have entered the home is to use a vacuum cleaner.
Sarah Browning is an Extension Educator with University of Nebraska- Lincoln Extension in Dodge and Saunders Counties. She can be contacted by phone at 727-2775: by mail at 1206 W. 23rd Street, Fremont, NE 68025: or by e-mail at sbrowning2@unl.edu
