Pest Library | Boxelder Bugs

Boisea trivittatus

Box elder bugs - Boisea trivittatus
Color: Black with orange or red markings
Legs: 6
Shape: Oblong
Size: 1/2-inch long
Antennae: Yes
Region: Throughout the United States
Boxelder Bugs are a North American species of true bug, as the Boxelder Bug, the Zug, or Maple Bug. It is found primarily on boxelder trees, as well as maple and ash trees.


Boxelder bugs emerge from overwintering sites during spring as the weather starts to warm up. Adults feed on low vegetation and seeds on the ground during spring and early summer and begin mating a couple weeks after they started feeding. Starting in mid‑July, they move to female seed-bearing boxelder trees where they lay eggs on trunks, branches, and leaves. They are rarely found on male boxelder trees. Boxelder bugs may also feed on maple or ash trees. There is no noticeable feeding injury to these trees. During years of high populations, you may find nymphs on the ground or in gardens feeding throughout the summer.


It is found primarily on boxelder trees, as well as maple and ash trees.


Boxelder bugs are primarily a nuisance because they enter homes and other buildings, often in large numbers. Fortunately, they do not bite people and are essentially harmless to property. When abundant, they can stain walls, curtains, and other surfaces with their excrement. Occasionally some may seek moisture and may be found around houseplants, although they rarely attack them. In the few cases when they do feed, boxelder bugs are very unlikely to injure indoor plants.


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.

* Information courtesy of Wikipedia and University of Minnesota Extension

* Image courtesy of Bruce Marlin