Vasates quadripedes
Ronald S. Kelley, Vermont Department of Forests, Parks and Recreation
Maple Gall Mites are tiny
cousins of spiders which make galls on maple leaves. These
galls are sometimes called "bladder galls." The bladder galls are
green at first, turning red and then black. Sometimes there
are so many galls on one leaf that nearly the entire surface
is covered. Canadian Forest
Service Canadian Forest
Service Bladder galls form when
adult mites start feeding in early Spring. The mites munch
on newly-forming leaves, and as the leaves grow, leaf tissue
grows out and forms a gall around each mite. The gall help
protects mites from predators. Once a leaf is full size,
each mite lays eggs and dies. Eggs hatch quickly, with
hundreds of tiny nymphs inside each bladder gall. Nymphs are
carrot-shaped and worm-like. They are whitish-orange with
two pairs of legs. Once the nymphs have
grown into adults, they leave their gall and crawl to new
leaves. The cycle continues until late Summer when the tree
stops new leaf growth for the year. These parasites cause
very little damage to the tree. Adult mites overwinter
beneath bark on the host tree. Canadian Forest
Service
Minnesota Department of Natural Resources Archives
