Andricus chrysolepidis
Ovate or globular, nippled, presumably twig gall containing a larval cell and covered with a dense, fine, short, pubescence, diameter 5 to 8 mm, on Q chrysolepis.
”- EP Felt: (1917) Key to American Insect Galls©
Reference: https://www.biodiversitylibrary.org/page/8635466#page/72/mode/1up