Another Andricus opertus, I suppose. Blue oak host.
on California Scrub oak
This observation is for the little bud on the right with the exit hole
On Quercus garryana tended by European paper wasp.
Galls on leaf of OR white oak
I saw this on several old brown leaves, but couldn’t find any on green leaves
on blue oak; same individual as in https://www.inaturalist.org/observations/209030724