About Eriosoma americanum (Riley, 1879)
Eriosoma americanum, commonly known as the woolly elm aphid, is an aphid species native to North America. It occurs in areas where Saskatoon (Amelanchier alnifolia) and American elm (Ulmus americana) trees are established. This aphid feeds on Saskatoon from late spring through fall, and feeds on American elm during early spring and late fall. Infestations on American elm produce symptoms including curled elm leaves, which are later followed by visible masses of dark areas and cottony masses. Like other aphid species, Eriosoma americanum excretes honeydew after feeding on plant sap, so honeydew can often be found on infected leaves.
