Males, which are white and narrow, congregate in large numbers on the undersides of leaves. There are two generations per season. One species causes pits to form in the bark. Foliage may have a grayish appearance. Female scales are circular, convex, and gray with a small yellow center.
Males are smaller, narrow, and white with a ridge down the center.
The insects overwinter in nearly full grown condition. Egg laying begins in May and the new brood appears about mid-June. There is only one generation per year. The insect overwinters in the egg stage under the female scale. May. Occurs on lilac, maple, poplar, and willow.