Oak galls are a common tree problem that has been historically overlooked as a cosmetic disease. But now we know that without the right care, they can cause leaf browning and dieback and cut off essential nutrients to twigs. If an infestation is severe enough, oak galls can kill the tree.
What Causes Oak Gall?
Oak gall is an abnormal growth on trees caused by wasps or other insects laying eggs inside the branches or feeding on the tree. The galls form to protect the insect inside. They often have bark coloring and can enlarge up to two inches and become woody. Repeated lifecycles of wasps can cause galls to form across the tree continuously.
New Treatments For Oak Gall Are Currently Being Tested
While oak gall is a problem that cannot be cured, it can be treated. Arborists and scientists constantly work to develop safe, effective treatments that protect trees from infestations. One of these new treatments is a chemical treatment to prevent the formation of galls—and short-term results look promising!
This new treatment protocol currently being tested by arborists for good long-term results includes injecting an insecticide that stays active in the tree for two years. This longevity is designed to provide control at the various life stages of the wasp, staying active within the woody parts of the tree.
A second chemical is used to impact the leaf tissue, repel wasps laying eggs on the leaf surface, and remain active for a couple of years. This dual treatment targets both of the major life stages of the wasp and appears to reduce the formation of new galls.
These Treatments Prevent The Spread Of Oak Gall
It’s important to remember that the treatment does not kill the current infestation. It works to keep the infestation from spreading throughout the remainder of the tree and to neighboring trees.