Scale is one of the more common insects found in trees and shrubs in Bucks and Montgomery County. Both hard shell and soft scale can be found in deciduous and coniferous plants. Proper identification is important when choosing appropriate methods of control. Depending on the time of year, eggs, nymphs or adults may be found on twigs and branches as well as the underside of leaves. In our area, some scale insects may have as many as two to three generations in one season. Some scale will excrete a sugary, sticky substance called honeydew, especially in the spring. Sooty mold tends to grow on this scale excrement, attracting ants, bees and wasps. Severe infestations can lead to dead branches and stunted twig growth as well as stunted, yellow leaves and premature leaf drop.
Properly timed twig and branch horticultural oil applications may provide adequate control. Depending on the time of year and host, foliar sprays, systemic soil injections or basal bark sprays may be better options.
Contact Plant Health Solutions for proper diagnosis and to develop a treatment pan.