Eastern Tent caterpillars build white silken tents in the crotches of tree branches each spring. The favorite host plant of these caterpillars are wild cherry and apple trees, but they also feed on peach, plum, pear, crabapple, rose, hawthorn, and many different shade and forest trees.

In addition to making a tree look unsightly with the webs it constructs in the crotches of limbs, the caterpillars also have big appetites and can completely defoliate a tree. There are four life stages of this moth: egg, larva, pupa, and adult. Eggs laid in July hatch the following March. After the caterpillars begin feeding, they spin threads of silk to form a tent together as they migrate up and down branches. Tents are enlarged as the caterpillars grow. The larvae leave the tent several times a day to feed.

The larvae become fully grown about six weeks after hatching and are almost two inches long, black, sparsely hairy, with some white and blue markings on their sides. There is a white stripe down the middle of the back. At maturity, the caterpillars migrate down the tree trunk and form cocoons on the bark of trees, in grass, or under objects. After about three weeks in the cocoon, and adult moth emerges, typically at night. Only one generation occurs per year.

For more information, consult UT Extension publication 341-N, The Eastern Tent Caterpillar and Its Control, found here.

Where trees are small and only a few caterpillars are present, the following techniques can be used for control:

• Hand destruction of webs and larvae

• Pruning out webs and destroying them

• Destroying egg masses before spring

• Removing wild cherry trees commonly infected

The best time to use chemical control measures for tent caterpillars is while they are still small and before leaves are half-open on wild cherry trees. Thorough application of a recommended insecticide at this time can eliminate the insect from the plant. Do not wait for tents to be present before attempting to apply chemical control measures.

For chemical control recommendations, consult the Insect and Plant Disease Control Manual, UT Extension Publication 1690, found here. Please contact your local Extension office for specific pesticide recommendations.