Box Elder Bug Infestation

Box elder bugs generally become a problem when they infest the inside of homes, storage sheds, or garages. While they are considered to be an outdoor pest, they are able to infest homes as the result of their need for shelter to overwinter. Outside, they infest and feed upon many kinds of plants, including box elder and maple trees, plus cherry, plum, and peach trees. As winter ends and spring approaches, a homeowner may again see evidence of box elder bugs as they attempt to leave their overwintering site and go back outdoors. Indoors, box elder bugs are an annoyance, as they can stain household items with their excrement.

Homeowners may be tempted to cut down a box elder or maple tree if they have an infestation of box elder bugs; however, that is generally not a prudent thing to do since these are mobile insects.

Based upon infestations reported, there are certain structures more apt to be staging locations for box elder bugs that congregate outside before going inside. Homes that are especially attractive are those with a lot of sun exposure, higher than others in the neighborhood, or on flat ground with no other surrounding buildings. Color does not seem to be all that important since box elder bugs are found on buildings of all tones and tints. Favored overwintering sites include cracks, gaps, holes, and voids in walls. Attics are also common places for box elder bugs to overwinter. Not all box elder bugs will seek shelter inside because the fissures of tree bark and debris also afford protection and escape from colder weather.

Control of a box elder bug infestation may include:

  • Contacting your local pest management professional for advice on how to help control box elder bugs.
  • Sealing cracks, gaps, holes, and spaces around where conduit and plumbing lines enter the home, beneath siding, and under eaves – all common places that box elder bugs use to get inside.
  • Replacing worn screens, as well as door and window seals to prevent entry.
  • If safe and not likely to hinder the function of a vent, covering vent openings with screen wire.
  • Using weep hole plugs to keep box elder bugs from getting indoors.
  • Using a vacuum or broom to mechanically remove box elder bugs that are seen inside and outside. After using the vacuum, be sure to empty the vacuum bag.
  • Spraying host trees to reduce the box elder population.
  • Spraying or dusting a residual product to kill box elder bugs before they have the chance to move inside. Also, it may be helpful to apply a perimeter barrier spray around where the ground and foundation meet.