Woolly alder aphid on red maple has been reported rarely. Plants infested with the woolly alder aphid are easily recognized by the presence of large, fuzzy, white colonies of these insects on the foliage, twigs or bark. Although their presence usually causes alarm and is a real nuisance, these aphids apparently cause little permanent damage to their host plants. They suck plant juices and secrete much honeydew. Dark sooty molds growing in the honeydew often disfigure the surfaces beneath infested trees.
Sidewalks become sticky, and bees, wasps and flies are attracted to the sweet liquid.
Infested leaves shrivel and drop prematurely. Eggs of the woolly alder aphid overwinter in cracks and crevices on the bark of silver maple trees. In spring, nymphs emerge and begin feeding at the midvein on the underside of new leaves. All the young are females which give birth to live young and produce large colonies. Their feeding on the foliage causes the leaves to curl and pucker.