Oak Apple Galls: Red Balls on Leaves, Harmless

Bright red cherry-tomato-sized balls on sunny-side oak leaves. Only this tree affected. Owner asks if galls.

Yes: Oak Apple Gall

Cynipid wasp lays egg in leaf; chemical induces gall. Single larva in hard center. Green → light brown papery.

Impact

• Minor: possible early leaf drop.
• No health threat.
• Natural enemies control wasps.

Management

None needed. Prune off on small ornamentals if unsightly.