US Forest Service, Northeastern Area, State and Private Forestry logo United States
Department of
Agriculture
Forest Service Northeastern Area NA-FB-37-February 1990

The Eastern Tent Caterpillar

The eastern tent caterpillar is often mistaken for the gypsy moth. Though they are similar in appearance, they differ in habits.

The fully grown eastern tent caterpillar is about 2 inches long, black with a white stripe along the middle of the back and a row of pale blue oval spots on each side. It is sparsely covered with fine light brown hairs.

The gypsy moth caterpillar, when fully grown, is also about 2 inches long, but it has pairs of blue and red spots on its back. Compare the photos in Figures 1 and 2 to see the difference.
Figure 1. Eastern Tent Caterpillar. Figure 2. Gypsy Moth Caterpillar.

Unlike the gypsy moth, the eastern tent caterpillar can be readily identified by the tent it constructs in the forks of tree branches (see Figure 3).

Tent caterpillars spend the winter in egg masses that are in shiny brown bands around twigs (see Figure 4).

Figure 3. Figure 4. Figure 5.

The gregarious caterpillars hatch in the earlly spring about the time tree buds start to open, and soon they begin to spin their silken tents in the branch forks (see Figure 5). The tent protects them from predators, such as birds, and from temperature extremes. Enlarging the tent as they grown, the caterpillars leave only to feed, usually at night.

The eastern tent caterpillar is found most often on apple and wild or ornamental cherry, and occassionally on pecan, hawthorne, beech and willow. When abundant, caterpillars will eat all the leaves, weakening, though seldom killing a tree.

Leaf-feeding can be prevented on small trees by destroying tents with a stick or pole, exposing the caterpillars to birds. Another preventive method is to prune the egg masses from twigs before the early spring hatch.

For more information, contact your county extension agent or the State Forester.

Authors:

Robert Rabaglia, Maryland Department of Agriculture
Daniel Twardus, USDA Forest Service

For additional information, contact:
USDA Forest Service
Forest Health Protection
180 Canfield Street
Morgantown, WV 26505
(304) 285-1541
USDA Forest Service
Forest Health Protection
271 Mast Road
Durham, NH 03824-0640
(603) 868-7704
USDA Forest Service
Forest Health Protection
1992 Folwell Avenue
St. Paul, MN 55108-1099
(612) 649-5261