In a healthy orchard ecosystem, woolly apple aphid is rarely a pest. Many natural enemies attack the aphids, from a specialist parasitoid to generalists such as syrphid flied. Outbreaks occur when these natural enemies are disrupted by insecticides. Woolly apple aphid has been a problematic secondary pest in Washington State for the past ten years. Feeding can cause distorted growth of buds and shoots, and aphid honeydew serves as a host of sooty mold. Growers have some options for management early in the growing season, but insecticides are less effective late in the season, especially right before harvest.
