Boxelder Bug nymph
Scientific Name: Boisea trivittata
Order & Family: Order Hemiptera, Family Rhopalidae
Size: Nymphs range from 1/16 to 1/2 inch (1.6 to 12.7 mm) depending on the instar stage.

Natural Habitat
Typically found near boxelder, maple, and ash trees; often observed congregating on the sunny South or West sides of buildings in autumn.
Diet & Feeding
Primarily feeds on the seeds of female boxelder trees but also consumes sap from leaves and twigs of maple and ash trees.
Behavior Patterns
Nymphs are bright red and lack fully developed wings. They move in large groups to stay warm and seek sheltered crevices, such as house siding or wall voids, to overwinter.
Risks & Benefits
Generally considered a nuisance pest rather than a threat. They do not bite or sting and do not cause significant damage to trees, but their excrement can stain light-colored fabrics or walls.
Identified on: 3/31/2026