Callirhytis perdens (Hymenoptera: Cynipidae)
Ruptured Twig Gall Wasp
La Honda, San Mateo County, California
November 12, 2017

Stem cut away showing one larval chamber of the gall inducer wasp. The chamber is cut open here, showing the cynipid (wasp) larva. Host is Quercus agrifolia.