Yellow or whitish spots appear on the leaves. Most of the leaves may drop by midsummer. Branches often die, and heavy infestations may kill the plant. The stems and lower surfaces of leaves are covered with somewhat flattened, white, scaly bumps and dark brown oyster-shell-shaped bumps. In severe cases, the whole plant appears white.
Euonymus scales may be hard to detect until after they have caused serious damage. Check the plant periodically for yellow spotting and scales. During the winter, check the base of the plant for hidden overwintering females. Apply a horticultural oil, following directions on the label. For very heavy infestations, cut plants to the ground.