Callirhytis apicalis (Ashmead)

Andricus apicalis

This species was described from material from Quercus wislizeni A. de Candolle. The writer has taken galls on that oak in the San Gabriel Mountains, at Los Gatos, and Bagby, California. He has also found them on Quercus californica Cooper in Sequoia National Park, at Los Gatos and Dunsmuir, California, and on Quercus agrifolia Nee at Carpinteria, Santa Margarita, Paraiso Springs, Los Gatos, and St. Helena, California. The fresh galls are greenish-white, tinged with red if exposed to light, fleshy, single, or in groups of a few or in clusters that may be as much as 8 cm. in diameter and contain as many as 35 galls. The fresh galls are found in May in all stages of growth. By June 1 they are full grown. They then turn brown and the juicy interior becomes converted into brittle, cavernous tissue, with a series of thin plates radiating out from the hard basal cell. In galls taken to Evanston, Illinois, pupae were found by September 1 and also on October 10, November 17 (transformed December 6), and December 23. Living adults were cut out of this lot of galls on December 23, March 20, and April 18. Some larvae do not pupate until the second autumn, however. The normal emergence is probably in early spring, one of the type series having been reared February 17. After the insects escape, the peripheral tissues weather away in time, leaving the rough hard larval cells attached to the bark to persist for years.

- LH Weld: (1921) American gallflies of the family Cynipidae producing subterranean galls on oak^©

Reference: https://www.biodiversitylibrary.org/page/7562993#page/276/mode/1up