Besbicus heldae (Hymenoptera: Cynipidae)   (Synonym: Cynips heldae)
Thorn Gall Wasp
Atchison Campground, Mendocino National Forest, Glenn County, California
May 21, 2012

Bud gall from Quercus garryana (Oregon white oak). The gall has been cut open, exposing the larva of the wasp that created this gall.