Boxelder Bugs and Insects That Look Like Them

A pamphlet by MCA Tehotiiennawakon Department

Boxelder Bugs

The bodies of boxelder bugs are black in color and are marked by red lines along the thorax and sides. Their wings are flat and red. Boxelder bugs measure between 11 to 14 mm long.

Behavior, Diet & Habits

Boxelder bugs do not nest indoors year-round. Rather, they make their homes in boxelder, maple and ash trees during warmer seasons and migrate into buildings and homes to find shelter for the winter. They enter through small cracks and crevices within the building, and remain inside, hibernating, through fall and winter. They emerge when heat sources within the building are high and can be located in the warmest areas of a structure's walls. While they do not cause damage to buildings, their droppings are unsightly and leave stains on furniture and linens.

Adult bugs live and breed on the leaves of boxelder trees, laying their eggs in spring. They feed on soft parts of boxelder trees, including leaves, flowers and new twigs. They also extract juices, causing minimal to substantial damage to their host tree. Boxelder bugs are not a serious problem every year. They are most abundant during hot, dry summers when followed by warm springs. They were very numerous in 1988, 1987, 1978.

Kissing Bug & Western Conifer Seed Bug

The kissing bug and the western conifer seed bug have a narrow head compared to the boxelder bug. The kissing bug has not been identified in our area but the western conifer seed bug has been. The kissing bug is known to bite people around the mouth area while they are asleep. The western conifer seed bug is not dangerous. There is no danger from the boxelder or milkweed bug.

Management

The best management of boxelder bugs is prevention – take steps to keep them from entering your home from the start. You can partly do this through exclusion though it largely depends on how your home was constructed. Make any repairs by the end of August.

For All Homes

• Repair or replace damaged window and door screens.

• Repair or replace damaged screens in roof and soffit vents and in bathroom and kitchen sinks.

• Seal areas where cable TV wires, phone lines, and other utility wires and pipes, outdoor faucets, dryer vents and similar objects enter buildings.

• Seal with caulk or for larger spaces use polyurethane expandable spray foam, copper mesh, or other appropriate sealant.

• Install door sweeps or thresholds to all exterior entry doors. Install rubber seal along the bottom of garage doors.

Are insecticides necessary?

You may want to supplement non-chemical methods with an insecticide treatment around the exterior of your home, especially if a large number of boxelder bugs are present and/or you have a history of boxelder bug invasions. The best time to spray is late summer and fall when boxelder bugs are first clustering around the outside of buildings.

Indoors

Once boxelder bugs are found the best option is to physically remove them with a vacuum or a broom and dust pan. If this occurs during fall, check around the building exterior because they can often be found congregating in sunny or warm areas. If they are close to entrances, an insecticide may be required to prevent their entrance into a home.

Inside homes, insecticides have limited value and are not usually suggested. Remember that when boxelder bugs are active, they so not live indoors much more than a few days and do not reproduce inside. When they are emerging from the walls and other sites where they have been dormant during the winter, spraying insecticides does not prevent more from returning.

Spraying or Removing Trees

Spraying or removing the seed-bearing boxelder trees in your yard is not a practical solution for the boxelder bug management because adult boxelder bugs can fly up to a couple miles from food. Also boxelder trees (as well as maple and ash) are usually common providing many potential sources of boxelder bugs. In our opinion, the benefits of having these trees in a landscape outweigh the problem of occasional infestations. Remember that although you may encounter large numbers of boxelder bugs in a given year, they are not automatically abundant every season.

MCA Tehotiiennawakon Department

101Tewesateni Road

Kawehnoke, ON

K6H 0G5

Phone: 613-936-1548

Email: [email protected]