Homeowners sometimes find themselves overwhelmed with large numbers of red and black bugs in fall and spring. The culprit is the boxelder bug – a common “true bug” that feeds on boxelder, ash, and maple. Immature and adult forms are often found in large congregations. In the fall, adult bugs begin looking for places to spend the winter in protected cracks and crevices – on trees, buildings, and other surfaces that get sun exposure. As they search for hidden areas to safely wait out the winter they may enter homes, to the frustration of the occupants.
Bunches of bugs! (courtesy UGA)
Don’t panic! Boxelder bugs may be a nuisance, but they are harmless. Spraying insecticides to control these bugs on homes is not recommended…since they occur in such large numbers, spraying them can result in piles of dead bugs hidden in wall voids, which can then be fed on by other pest insects such as carpet beetles. Vacuuming them up is the best indoor control. Outdoors, they can simply be washed off the home with a garden hose. For lasting control, it is necessary to identify the cracks and openings the bugs are using to get into the house, and seal them tightly. Boxelder bugs are a nuisance due to their sheer numbers, and their habit of seeking refuge in homes, but insecticide sprays will not stop them from entering and may cause other problems. If they are a persistent problem, some homeowners may consider hiring a lawn and ornamental company to apply an appropriate product to their trees and shrubs, reducing bug populations before they begin searching for a winter home.
Good luck, and thanks for reading! Next time, some common flies that can be a pest in homes.