Low to moderate populations apparently are not damaging, but heavy populations reduce terminal growth and vigor. The chief injury is the production of large amounts of honeydew. Sooty mold growing on the honeydew can cause blackened areas on leaves and fruit. If a high degree of parasitization is observed, treatments may be delayed until late spring after crawlers emerge. Treat during dormant or delayed dormant period if scale population or sooty mold was observed the previous year.
Organophosphate insecticides used during delayed dormancy are very toxic to honey bees.
Remove bees from orchard if cover crops or weeds are in bloom. Oil sprays may injure trees that are water stressed. It is advisable to postpone an oil application to water-stressed trees until winter rains have replenished soil water and the tree bark is noticeably moist. . . . Apply before blossoms open or injury may occur. Do not graze livestock in treated areas or feed them treated cover crops.