Eriosoma americanum

Eriosoma americanum, the woolly elm aphid, is an aphid native to North America, found where Saskatoon (Amelanchier alnifolia) and American elm (Ulmus americana) trees are established.

The aphid feeds on the Saskatoon in late spring through fall, and the American elm during both early spring and late fall.^[1]

Symptoms of American elm infestations include curled elm leaves, later accompanied by masses of visible dark areas and cottony masses. As with other aphids, honeydew may be found on infected leaves, excreted by the aphids after feeding on the plant's sap.