Sycophila sp. (Hymenoptera: Eurytomidae)
Sunol Regional Park, Sunol, Alameda County, California
May 29, 2006

This is an opened Besbicus conspicuus gall from Quercus lobata, containing a Sycophila wasp inside (shiny bit in middle). Sycophila is a primary or secondary parasitoid of the creator of the gall. See the entire gall on tree.