Boxelder Bug

Typically found on boxelder, maple, and ash trees. They often congregate on the sunny south or west sides of buildings.

They feed primarily on the seeds, flowers, and leaves of host trees like the Boxelder maple (Acer negundo) using piercing-sucking mouthparts.

They are social insects known for clustering in large numbers. During autumn, they seek out cracks and crevices in human structures to overwinter. Nymphs (visible as bright red in the image) undergo several molts before reaching maturity.

They are generally harmless to humans and do not cause significant damage to properties or trees. However, they are considered a nuisance pest due to their large numbers and can leave red stains from their excrement or if crushed.