Only a few species are barely discernable with the unaided eye. Many species are yet to be found and identified. Eriophyids reproduce rapidly and may increase to great populations, especially the rust mites. They are highly specialized plant feeders.
Damage appears to be slight.
Heavy fine stippling induces a blemishing or staining of leaf surfaces and fruit. May result in a great loss of water. Thus, the modified leaf provides shelter as well as food. Most galls are on the leaves but some are on flowers, petioles, green stems, and even roots. Some erinea on the undersurface are domed up and distort the upper leaf surface.