Pest description and crop damage Lecanium scale are about 0.125 inch in diameter and vary from red to dark brown in color. They are oval and raised, resembling small helmets or bumps on branches, stems, and the underside of leaves.
Biology and life history Lecanium scale overwinters as an immature scale or a fertilized female on twigs and branches. They resume feeding in the spring, and eggs are laid underneath the scale in May-June. The eggs remain under the scale until hatching in early summer. The young scale are yellowish brown and flattened. These migrate to the undersides of leaves to feed. Young scale also can be dispersed by wind, rain, irrigation, or by the movement of people and machinery. After 4 to 6 weeks on the leaves, the young return to the stems and twigs to feed, mate, and overwinter. There is one generation per year.
Apply in July, August, or early September to control crawlers.