It is considered the most important insect pest of sycamore trees in California. To detect this pest, examine the yellowish to brown dots on the undersides of leaves with a hand lens. A tiny scale will be present in the center of the spot.
Scales are yellow to brown at maturity.
Females can be recognized by the cottony white tufts that emerge from beneath the body and protrude from bark cracks and crevices. When the eggs hatch, the young crawlers are also orangish yellow in color. In late winter, eggs are laid and the immature scales, known as crawlers, move to leaf buds as they begin to open in spring. As leaves expand, young scale nymphs settle at feeding sites on the undersurfaces of leaves. There are several generations each year.