Disholcaspis eldoradensis (Hymenoptera: Cynipidae)
Honey Dew Gall Wasp
Sunol Regional Park, Sunol, Alameda County, California
October 7, 2006

The western yellowjacket (Vespula pensylvanica) is eating honeydew secreted by the cynipid wasp gall. Three of the galls are visible in this photo.