Callirhytis quercussuttoni (Hymenoptera: Cynipidae)
Knowland Park, Oakland, Alameda County, California
November 7, 2021

Root gall caused by gall wasps. Host is Quercus agrifolia (coast live oak). Here the gall was detached from the tree and sawed open to expose the larval chambers. In this image, the darker oval areas are where adult wasps emerged. The lighter area in the lower right shows a very small larva. It's unclear if this larva is an inducer or an inquiline (guest). The large range of stages of development of gall occupants in this gall was unlike what I've seen in other CA oak galls. Some wasps had already emerged, some were adults but waiting to emerge in January, and some were tiny larvae.