Eastern Tent Caterpillar​

Identification

The eastern tent caterpillar is often mistaken for the spongy 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 spongy 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.

Unlike the spongy moth, the eastern tent caterpillar can be readily identified by the tent it constructs in the forks of tree branches (see Figure 4). Tent caterpillars spend the winter in egg masses that are in shiny brown bands around twigs 

Hosts

The eastern tent caterpillar is found most often on apple and wild or ornamental cherry, and occassionally on pecan, hawthorne, beech and willow. 

Biology

The gregarious caterpillars hatch in the early 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 grow, the caterpillars leave only to feed, usually at night. 

Control

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.

More Information  

USDA Forest Service Forest Health Protection
180 Canfield Street
Morgantown, WV 26505 
(304) 285-1541 

Forest Pest Management Maryland Department of Agriculture
50 Harry S Truman Pkwy
Annapolis, MD  21401
(410) 841-5922

University of Maryland Extension: Eastern Tent Caterpillars and Forest Tent Caterpillars on Trees