The infestation caused by this mite results in the formation of peculiar galls involving the midrib and lateral veins of the upper surface of the leaves. The galls consist of pouchlike swellings arising from the leaf surface around the midrib and lateral veins, with the edges meeting over the veins to form "globular chambers." The galls coalesce and are covered with whitish hairs, which make them conspicuous and unmistakable. Galled leaves are considerably deformed.

Specimens were found in the galls on Sierra gooseberry in California and on coastal black gooseberry on Oreas Island, Wash., in September. Nearly every leaf of a plant was reported to be galled

- Hartford Keifer, Edward Baker, Tokuwo Kono, Mercedes Delfinado, William Styer: (1982) An Illustrated Guide to Plant Abnormalities Caused by Eriophyid Mites in North America^©

Reference: https://babel.hathitrust.org/cgi/pt?id=uiug.30112019256624&view=1up&seq=70&q1=ribes