Problem: Scales (Jasmine)
Many types of scales infest jasmine shrubs and vines. They lay their eggs on the leaves or bark, and in spring to midsummer the young scales, called crawlers, settle on leaves and twigs. The small (1/10-inch), soft-bodied young feed by sucking sap from the plant. The legs usually atrophy, and a hard crusty or waxy shell develops over the body. Mature female scales lay their eggs underneath their shells. Some species of scales that infest jasmine 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 jasmine leaves to appear black and dirty.
Apply an insecticide labeled for scales, following label directions.