Blackthorn Gall

Blackthorn Gall

Observation - Blackthorn Gall. Description: A gall seen along the edges of Blackthorn leaves. Research has led me to believe that it is an Eriophyes sp. either E. similis or E. prunispinosae but I don't know how to distinguish between these two species. If anyone knows or can point me in the right

A gall seen along the edges of Blackthorn leaves. Research has led me to believe that it is an Eriophyes sp. either E. similis or E. prunispinosae but I don't know how to distinguish between these two species. If anyone knows or can point me in the right direction I would very much appreciate it.