Pine needle scale (Chionaspis pinifoliae)
Pest description and crop damage Pine needle scale and Matsucoccus scale are among the scale that attack arborvitae. Scale are closely related to aphid, mealybugs, and whiteflies and, like these insects, also have piercing-sucking mouthparts. Large populations of scale can devitalize plants and retard growth, as well as discolor the foliage. Severe infestations can kill twigs. Large quantities of honeydew are produced by soft scale, which makes leaves and fruit shiny and sticky. Black sooty mold fungus may grow on this, giving the plants a dirty, sooty appearance.