Maple-parasite
Guides
Aceria calaceris
Rocky Mountain maple felt mite
Aceria calaceris, the Rocky Mountain maple felt mite, is an eriophyid mite that induces distinctive felt-like galls called erinea on maple leaves. This microscopic species was first described by Hartford H. Keifer in 1952 from Fallen Leaf Lake. It has a complex life cycle involving two female morphs—protogynes for reproduction and deutogynes for overwintering—plus a single male form. The species is found in the western United States and Canada, where it specializes on three maple species.
Vasates aceriscrumena
maple spindle-gall mite
An eriophyid mite that induces distinctive fusiform (spindle-shaped) galls on maple leaves in the eastern United States. The microscopic mite is visible only through the galls it produces. Unlike the related maple bladder-gall mite, its galls are elongate rather than rounded. The species causes minimal harm to host trees despite the conspicuous galls.