The maple bladder gall mite, Vasates quadripedes (Shimer), is a tiny eriophyid mite that is associated with red, sugar, and silver maples. The mite feeding on the leaf underside forms the colorful galls on the upper surface of the maple leaves. The mites live within the galls. The damage is generally cosmetic and not permanent, although there are reports of the mites causing extensive leaf damage in some situations.
Another mite, Vasates aceriscrumena (Riley). causes maple spindle galls on silver maples. Images of another spindle gall mite on Linden are posted here at this website.
Management of these mites, if required, should occur prior to the leaf damage. Most information sources suggest the timing should coincide with early leaf development and expansion when the mites have moved out from their overwintering sites in the bark and branch crevices.
More information on these mites and their management can be found at the links.
Amrine, J. 2013. Eriophyid mites. WSU Puyallup REC. <23 April 2015>
BugGuide: Maple bladder gall mite. Great images of the galls at this site.
Hoover, G. 2004. Leaf galls on maples. Penn State Entomology.
Pellitteri, P.J., C.F. Koval, and D.L. Mahr. Maple gall mites. University of Wisconsin Cooperative Extension. A2691.
Shetlar, D. and J. Andon. 2015. Galls of Maple Trees in Ohio. Ohio State University. Ent-60-15. <23 April 2015>
Maple gall mite: More nice images.
Page last modified 4/23/15