If you wish to try and avoid chemical pesticides there is a simple alternative, soap and water. Just add 1 or 2 Tbsp (15 to 30 ml) of dish soap to a standard-size spray bottle filled with water. Shake well to combine, and spray the soapy solution on boxelder bugs as you see them. This solution in theory deteriorates their hardened skin exterior of the insect which results in dehydration. If trying this method make sure to spray the insect directly. Prevention is always more efficient, but this may be a great option for anyone sensitive to chemical pesticides.