Maple Bladder-gall Mite
''Vasates quadripedes'', the maple bladder-gall mite, is an eriophyid mite in the genus ''Vasates'', which causes galls on the leaves of silver maple , red maple , and sugar maple. The gall is rounded, sometimes elongate, and has a short, thin neck. Typically, galls are 2–3 millimetres in diameter, and may be numerous on the upper surfaces of leaves. They have an opening in the lower surface. At first they are yellowish-green or bright red, later they become dark red and black.