About Aceria brachytarsus (Keifer, 1939)
Aceria brachytarsus, first described by Keifer in 1939, was formerly classified under the name Eriophyes brachytarsus. It is commonly called the pouch gall mite or the walnut purse gall mite. This species is an eriophyoid mite that creates leaf-pouch galls on multiple walnut tree species, including Juglans californica. Galls formed by this mite resemble bladder galls when they first develop. Observations of these galls have been recorded in California, Iran, and Spain.
