Forest Tent Caterpillar

The forest tent caterpillar, is a native species found throughout hardwood forests of North America. It feeds on the leaves of many trees, but in Michigan, Minnesota and Wisconsin, outbreaks occur in aspen, birch, basswood and oak stands. Sugar maple is a favorite host in Michigan's Lower Peninsula, but is not highly preferred in other parts of the Midwest. Regional outbreaks occur at 5-15 year intervals, each outbreak lasting 2-5 years. At the peak of an outbreak, millions of acres of trees can be stripped of their leaves by mid-summer. When full-grown, caterpillars are about 2 inches long. The moth stage of FTC is light brown with a wingspan of 1 to 1 1/2 inches. The forewings have two darker lines. Egg masses encircle twigs and are dark gray to black and covered with a frothy, glue-like substance. Each egg mass contains 100-350 eggs.