Treating Oak Galls
What are Oak Galls?
Oak galls are abnormal growths found on foliage and twigs, created by small oak gall wasps. Inside these galls, the wasps lay their eggs, and the larvae develop within. Galls are made of plant material and exhibit various colors, starting from yellow and green and eventually turning tan-brown as development continues. Once the adult insect emerges, the galls will brown and die. In Central Missouri, various oak species can host gall wasps, with post oak trees and pin oak trees being the most common hosts.
Galls form when the wasp secretes a chemical that disrupts normal plant cell growth. The adult wasps lay eggs in expanding tree buds and leaves during the spring. Larvae then feed, pupate, and emerge from the gall as adult wasps. While galls themselves do not cause significant damage to trees, they can be unsightly and impact the overall aesthetics of your oak trees.
What Does Treatment Look Like?
Prevention is key when it comes to managing oak galls. Selecting oak tree varieties that are more resistant to gall wasps can significantly reduce the risk of infestation. Our knowledgeable team can guide you in choosing suitable oak species that exhibit natural resistance to oak galls, ensuring long-term protection and minimizing the need for extensive treatment.
While treatment cannot remove existing galls, it can prevent the formation of new ones. At Korte Tree Care, we have found that two injections of Emamectin Benzoate directly into the tree, spaced two years apart, effectively kill the wasps and break their life cycle. Monitoring the trees thereafter is crucial, and if galls reappear, continued treatment is recommended.
