Trisetacus gemmavitians ... causes a peculiar gall, which essentially is a conspicuous, beautiful rosette easily seen on pine trees. Each rosette consists of a cluster of aborted buds or stunted needles. Typically the shoots become infested, and the elongation of the growing point is inhibited. Numerous buds are clustered at the tip, and the needles that develop from these buds are stunted. When rosettes are numerous, the value of cut pine trees is greatly reduced. Infestations occur at the base of the needle beneath the sheath. The mites have been collected in the sheaths of stunted needles and in new buds. Trisetacus gemmavitians has been reported from Ohio and California.
[pg. 90]

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