Callirhytis carmelensis (Hymenoptera: Cynipidae)
Mottled Acorn Gall Wasp
Del Valle Regional Park, Livermore, Alameda County, California
April 24, 2021

Acorn gall (with wasp larva inside) on host Quercus agrifolia (coast live oak). The ants are eating honeydew secreted by the gall. The tip of the severely stunted green acorn ovary is visible on the forward-facing side of the acorn.