Boxelder Bug (Boisea trivittata)
Detailing the identifying qualities of the Boxelder Bug, including physical features and territorial reach.
Updated: 2/9/2018; Authored By Staff Writer; Content ©www.InsectIdentification.org
Boxelder Bugs can form massive, intimidating mobs near dwellings and on trees, but they are harmless to humans and not a significant threat to plant life.
Boxelder Bugs are black plant bugs. They have thin orange or red-orange borders on their elytra (wing coverings). A short orange line runs down the middle of the thorax. Large red eyes bulge out the sides of its head and two tiny red spots on top of the head sit near them. Nymphs (juveniles) look different from adults. They have red bodies with an orange or yellow spot in the center of it. Their undeveloped wing coverings are short and black. They commiserate with older Boxelder Bugs, commonly form large congregations on the sides of homes, or on trees, but especially near Boxelder bushes, from which they are named. They prefer the warm and sunny sides of buildings. Females will overwinter inside walls and lay eggs on leaves in the spring.
Boxelder Bugs are not harmful to humans, but they will secrete a staining dye if crushed. If they are found indoors, it is best to remove them with a paper towel, or vacuum cleaner with its hose attachment, to avoid creating a mess. They do not emit any odors. Typically, Boxelder Bug can be found in parks, gardens, meadows, fields and forests. Adults, their larvae, and their growing nymphs drink nectar and sap from flowers, trees and other plants, but rarely with enough vigor to destroy them. The feeding may slightly deform fruits and their large numbers may startle observers, but they are not dangerous.