A dormant oil applied in late winter, prior to the male insect s emergence can reduce overwintering scale. Also, check nearby fruit trees for infestations, and spray with dormant oil, if necessary. Pruning and dormant oils are the best controls. Lime sulfur applied during late winter is an effective control for Rose Scale, but not as effective for San Jose Scale, which has developed a resistance. Rating Bad Guy .
Scale causes a slow progressive killing of twigs and stems.
Heavy infestations affect the plant s vigor and lead to death of the plant. The bushes most vulnerable are new bushes that arrive with infestations already in place. Inspect new bushes for any infestations. Otherwise, new infestations will generally come from a nearby host. Be aware that nearby fruit trees and other ornamental trees and shrubs can be carriers, especially of San Jose Scale.