Home | Pest Library | Customer Service | Site Map
In Tarrant County call 817-267-5201

Boxelder Bugs

Adult box elder bugs are about ½ inch long, dull black with red markings along the front edges of their wings.

They are predominantly attracted to the female box elder tree, also called an Ash-Leaved Maple, Acer Negundo. Female box elder trees can be identified by their winged seed pods. The box elder tree is their food source and that explains the attraction to it.

During spring, box elder bug adults and nymphs can be seen emerging from hibernation sites, flying to a box elder tree or gathering on the sides of buildings. At this time the overall size of box elder bug infestations on trees and buildings can be considerable smaller (differing as much as tenfold) than box elder bug infestations in the fall. Female box elder bugs emerging from hibernation begin to lay eggs in April and May.

The temperature of surfaces found around buildings can contribute to infestations of adult box elder bugs in the spring and fall. Research data, obtained by measuring the body temperature of box elder bugs and the temperature of different surfaces, shows that box elder bugs prefer surfaces with temperatures that are much higher than a box elder bugs normal body temperatures.

Several cold nights followed by an Indian summer cause box elder bugs to begin congregating on homes as they search for where to spend the winter.

In the fall there is an increase in the number of box elder bugs on host trees, and this increase is associated with development of the ovules on female box elder and maple trees. There are much fewer box elder bugs around buildings in the fall; most are found on trees. Adult box elder bugs move to overwintering sites during October. Although the same overwintering sites are not usually used by box elder bugs every year, there are some that are frequented on a regular basis.

Box elder bugs travel short or long distances (as much as two miles) from a box elder tree to a favorable hibernation site. Box elder bugs spend the winter in leaf litter next to buildings, under bark in protected areas or in other spaces in which large numbers of box elder bugs can gather for a few months.

Normally, October is the month in which box elder bugs become a pest. Box elder bugs begin to mass in large numbers on box elder tree trunks to prepare to overwinter. From the tree the box elder bugs move to wood and rock piles, fallen leaves, and the cracks and crevices of buildings. They are especially attracted to the sunny side of light colored homes. Box elder bugs creep into siding, window and door frames, porches, and cracks in masonry.

Box elder bugs do not bite, reproduce indoors, cause any structural damage, or cause health problems to humans or pets. Smashing box elder bugs can stain fabrics and wallpaper. Box elder bugs are merely a nuisance.

Moderate daytime temperatures are confusing to box elder bugs; it is normal to have a recurrence of the box elder bugs in the middle of winter when it is mild. Box elder Bugs come out of hiding and become active because it is so warm during the day, it seems like spring to them. As long as it is mild box elder bugs will congregate on box elder trees and light colored homes.