Since boxelder bugs usually overwinter near the trees that they feed on, the removal of one or two problem trees may be of benefit to the homeowner. Infested trees also can be sprayed with carbaryl insecticide while the bugs are still concentrated on the trees, before they move into the house. When the bugs begin to congregate on dwelling exteriors, these areas also may be sprayed. Treat all resting and hiding places. Insecticides registered for treating building exteriors will give residual control, that is, treated surfaces will remain toxic to the insects for several days.
Laundry detergents are cheap, safe and effective when applied directly to boxelder bugs.
Drawbacks of detergent sprays are that they will kill only if they contact the insect directly and they may damage vegetation. Screening or sealing cracks or other entrances into the dwelling is important because once boxelder bugs have entered the home, control becomes more difficult. A vacuum cleaner is useful for controlling bugs that have entered the house. Household insecticidal aerosols and many household spray cleaners also are effective when applied directly to individual insects. These measures will provide temporary relief only, because the boxelder bugs may continue to enter the home as they move about on warmer days throughout the fall, winter and early spring.