Brownish crusty bumps; thick, white, waxy bumps; or clusters of flattened yellowish, gray, or brownish scaly bumps cover the stems, small branches, or undersides of leaves. The bumps can be scraped or picked off; the undersides are usually soft. Leaves turn yellow and may drop. In some cases a shiny or sticky substance coats the leaves. A black sooty mold often grows on the substance.
Apply an insecticide labeled for this pest, following label directions.