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Archive for June 2, 2015

Gall-making Mites on Sugar Maple Leaves

S6-2-15 mite-making galls 060Within a week or two of unfurling, Sugar Maple leaves are attacked and consumed by all kinds of creatures, some of which are insects and mites that cause the leaves to develop abnormal growths called galls. Certain species of eriophyid mites form felt, or erineum, galls, often on Silver and Sugar Maple leaves. After spending the winter months under the scales of buds, these mites emerge in the spring when leaves appear, move out onto the surface of the leaves and begin to feed. Their feeding induces the growth of thousands of tightly-packed leaf hairs which provide shelter for the mites on the leaf surface. These hairs appear as bright pink or red patches that resemble felt. The mites, too small to even be seen with a hand lens, move to the inside of these structures for the rest of the growing season.

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