Andricus scutella [Russo's photo and description of A scutella do not entirely match those of Weld, who does not mention hair and specifies that the gall does not have an inrolled edge, which Russo's photo does]
Little-red-cup-gall wasp
[Page 185]
Hosts: Quercus oblongifolia, turbinella
Galls are hairy, rose pink to red-brown, and measure 2 mm high and wide.
”- Russo, Ronald A. : (2021) Plant Galls of the Western United States©