Galls cause homeowners much concern.
There are many types and galls can be on the leaves or twigs. Most galls are harmless so chemical controls are not suggested. Scales of several types are controlled with sprays of dormant oil applied in spring. Use Orthene applied 2 to 3 times at 7 to 10 intervals when the crawlers are first seen. Diazinon, Sevin or malathion are used whenever the crawlers are present.