Pin Oak Stem Galls: Harmless Wasp Galls, No Treatment Needed

Swollen Bubbles with Sawdust = Galls

Pin oak in GA with brittle bubbles on stems, sawdust inside, tiny bugs = gall wasps. Wasp lays eggs → chemical → tissue swells. Galls don't harm tree health.

Management

• No control needed.
• Leaf galls may cause early drop.
• Control must target wasp timing, not galls.

Resource

NC State extension on gall wasps.