Description:

Adults are flattened, about 1/2-inch long and 1/3-inch wide, brownish-gray to black bugs with characteristic red eyes, back and wing markings. The segment behind the head has three red lines running lengthwise. Immatures or nymphs are red and develop black markings and wing pads as they grow.

Life cycle:

Overwintered adult females deposit eggs in bark cracks and crevices in the spring at bud break. Nymphs hatch from eggs in about 2 weeks and develop through several stages (instars) during the summer before becoming winged adults. There may be two or more generations per year.

Pest Status:

Nymphs and adults suck juices primarily from seeds of boxelder trees, but also suck juices from fruits of other trees (e.g., plum, cherry, apple, peach, grape, chinaberry, western soapberry, ash and maple). Young fruit may be scarred or dimpled from feeding activities. In the fall, large nymphs and winged adults leave host plants in search of overwintering habitats. They enter homes through cracks and crevices around doors and window frames and around the foundation. They also overwinter in tree holes and in piles of debris around the landscape. In the spring adults reappear and often sun themselves on light colored walls. In homes, the bugs may stain curtains, paper and other objects with fecal material.

Control:

Prevention is a good way to keep boxelder bugs from moving into a house. Check the outside of the structure for any areas that boxelder bugs may find to be a suitable overwintering location. It is preferable to inspect and take any necessary exclusionary steps before August. Preventive actions include:
  * Seal cracks and crevices with caulk or expanding foam.
  * Using caulk or expanding foam, seal the areas where pipes or wires enter the structure.
  * Stuff weep holes with steel wool, copper mesh or plastic screening made
      specifically for weep holes (kits are available).
  * Replace or repair any damaged window screens.
  * Replace any damaged weather stripping around the doors.
  * If you can see daylight around the doors when closed, replace the weather stripping.
  * Install a door sweep on exterior doors and a rubber seal along the bottom
      of garage doors.
  * Repair or replace damaged screens or soffit vents in the roof and eaves area
      of the structure.

Please check the "Extension Agents' Handbook of Insects, Plant Disease and Weed Control".