Valley-oak
Guides
Andricus quercuscalifornicus
California Gall Wasp
Andricus quercuscalifornicus is a cynipid gall wasp that induces large oak apple galls on white oaks, primarily the valley oak (Quercus lobata). The species is considered an ecosystem engineer due to its ability to manipulate plant tissue growth, creating complex microhabitats that support diverse insect communities. No male specimens have ever been recovered; reproduction occurs strictly through parthenogenesis.