Boxelder bug nymphs

Found on and around boxelder, maple, and ash trees, often aggregating on sunny sides of structures.

They pierce plant tissues to feed primarily on developing seeds, leaves, and stems of host trees.

Nymphs gather in dense, conspicuous aggregations and undergo incomplete metamorphosis through five instars.

They do not bite or transmit diseases, but large aggregations can become minor household nuisances.