A heavy infestation can stunt a tree. Twigs with galls should be cut off and burned before larvae make their exit holes. Several scale insects are pests of dogwood. Scales are unusual insects in appearance. They are small and immobile, with no visible legs.
Scales vary in appearance depending on age, sex and species.
They may be found on leaves or stems and look like small brownish, grayish or blackish bumps. They feed on sap by piercing the leaf or stem with their mouthparts and sucking. If infestations are very heavy, they may cause leaf yellowing, stunting or branch dieback. Adult scales are relatively protected from insecticides by their waxy covering. However, immature forms, called crawlers, are susceptible.