Overwintering insects can be a real nuisance this time of year. Boxelder bugs, lady bugs, stink bugs, and cluster flies are probably the most common overwintering insects in the Virginia area. The adults of these insects survive the winter by finding a crack in the caulking, an opening caused by settlement or weather, or perhaps a screen that has torn or come out of the frame.
Once these pests gain entry into your home they find a place out of the weather and remain dormant until the arrival of warm, sunny days at which time they can emerge. Because the air is still too cold for them to begin their life cycle outside they wind up in your home or business gathered on a window sill or a wall inside the structure.
These pests are plant feeders so they will not harm anyone, but they can stain surfaces or emit a foul odor and they certainly are unsightly. The best way to remove a large group is to vacuum them up, but if you want to prevent the problem in the future you must attack it from the exterior.
Treating areas around your property to reduce pest populations and treating and sealing the openings that might allow these pests into the structure is the key to eliminating these types of infestations.