Maple and Other Trees Disorder: Cottony Maple Scale
Author(s) C. F. Koval, D. L. Mahr, P. J. Pellitteri.
Cottony maple scale is an insect that can infest the twigs of maples and other shade trees with popcorn-sized cottony masses. These masses produce a considerable amount of sticky liquid that resembles tree sap and eventually turns black due to fungal growth. Infestations are usually more severe in southern Wisconsin than in the north.
Cottony maple scale prefers silver maple, but it also attacks other maples and numerous other trees and shrubs, especially apple, basswood, beech, black locust, boxelder, dogwood, elm, hackberry, hawthorn, honeylocust, lilac, oak, poplar, rose, sumac, sycamore, white ash, willow, and others. Find out more about the insect's symptoms and life cycle as well as effective means of control in this handy publication (2 pages; Revised in 1996).