a gall, similar to the one made by P. proxima, is made by a species on the native S. lasiandra in the Sierra Nevada and adjacent ranges at elevations of 1660-2200 m, and it is unlikely that it will prove to be P. proxima.
[A photo of these galls appears in Figure 5A, page 6 of the pdf]
”- Edward L Smith: (1970) Biosystematics and morphology of Symphyta. II. Biology of gall-making nematine sawflies in the California region©