Problem: Scales (Ligustrum (Privet))
Many different types of scales infest privet. They lay their eggs on the leaves or bark, and in spring to midsummer the young scales, called crawlers, settle on leaves, twigs, or the trunk. These small (1/10 inch), soft-bodied young feed by sucking sap from the plant. The legs usually atrophy, and a hard crusty shell develops over the body. Mature female scales lay their eggs underneath their shells. Some species of scales that infest privet are unable to digest fully all the sugar in the plant sap, and they excrete the excess in a fluid called honeydew. A sooty mold fungus may develop on the honeydew, causing the privet leaves to appear black and dirty. An uncontrolled infestation of scales may kill twigs or branches after 2 or 3 seasons.
Apply an insecticide labeled for scales, following label directions.