Heteroecus chrysolepidis

Quercus chrysolepis
Stem galls, detachable
"Hard, ovate or globular, with a nipple, larval cell central; covered with a dense, fine, short pubescence as on a peach altho this is sometimes rubbed off." Diameter 5-8 mm.

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.

Heteroecus chrysolepidis (Ashmead)

Andricus chrysolepidis

Hosts: Quercus chrysolepis

Gall: A small, irregularly globular or ovate bud gall. Monothalamous. A slight nipple at the apex; the surface covered with a fine, scurfy pubescence, light brown in color; 7 mm in diameter by 10 mm long.

Range: CA

The insect is very close to dasydactyli. The gall is the most distinctive thing of the species. Galls from Diablo appear to match the type galls, but I do not have insects to check the determination. Unlike the type galls, some of the Diablo specimens are clustered, suggesting H. malus, and inasmuch as the insects of the two are rather similar perhaps malus should be considered a variety of chrysolepidis.