The Cherry Gall Wasp is a 3- to 4-mm-large brown-black gall wasp that causes the up to three-cm-sized galls on the underside of oak leaves.
Cherry Gall Wasp (Cynips quercusfolii L.). A 3- to 4-mm-large brown-black gall wasp that causes the up to three-cm-sized galls on the undersides of oak leaves. The galls consist of proliferating mesophyll.
The female gall wasp deposits eggs on the veins of the underside of leaves in summer. The egg activates the leaf in making a gall. In the gall lives the larva that pupates in the fall. In winter, the Cherry Gall Wasp emerges from the pupa and eats its way out.
