The following questions were sent to the P&PDL diagnosticians here at Purdue University:
Question 1: I have a number of black and red bugs covering my home. What are these little critters?
Question 2: What is the best way to remove hundreds/thousands of boxelder bugs from the exterior of my home--is there anything effective that I can mix with water to spray them?
Answer: These critters are called boxelder bugs. Boxelder bugs are common throughout the Midwest. Typically, they are most numerous in areas where boxelder trees grow.
In the fall, these bugs will congregate in large numbers inside homes and buildings to hibernate for the winter. When temperatures begin to warm up in late winter/early spring, they become quite active and leave their overwintering site. Frequently, boxelder bugs get caught indoors. Boxelder bugs will not damage fabric or furniture, but may stain these items with their excrement.
As boxelder bugs mass around the outside of the home, hot water (165 -180 degrees F) applied directly to the mass will kill them. To prevent the bugs from entering the home, make sure all doors and windows are properly screened and cracks are sealed. Remember, always read and follow all label directions before using pesticides.
-Corey Gerber, Insect Diagnostician