Staghorn sumac

Habitat:

Rural SW Pennsylvania

Notes:

Melaphis rhois is an aphid species known as the "Staghorn sumac aphid". It is a type of woolly aphid and one of the few aphids that induce the formation of galls. The species produce galls on the Staghorn sumac (Rhus typhina) when female aphids lay a single egg on the underside of the sumac leaf, inducing the leaf to form a sac about the size of a golf ball over the egg.