The Jewel Oak Gall Wasp is probably common on the Bur Oak trees (Quercus macrocarpa) in Fontenelle Forest and Neale Woods. The wasp pictured here was an autumn hatch wasp from which only asexual, wingless females are produced. These females may stay in the galls overwinter or even for 2 or more winters before emerging. Since these wasps are very small, they would not ordinarily be encountered unless one should happen to see one emerging from the gall. The galls can readily be seen. They are always on the underside of Bur Oak leaves attached along the vein.

Two populations are produced. The spring population is in galls on oak buds, flowers and leaves and are fully winged, short-lived males and females which are sexual. The larva develops in a single celled oval or round gall which is about 1/8 inch in diameter. The Jewel Oak Gall Wasp belongs to the Cynipinae subfamily. There are 640 species in the subfamily. Each species makes a characteristic gall on a specific part of the plant.