Spongy Moth Insects & Diseases Facts About Spongy Moths and Treatment Options What is a Spongy Moth? The spongy moth (Lymantria dispar) arrived in the United States from Europe in the 1860s. Spongy moths defoliate trees while in the larval stage. After multiple seasons of defoliation, formerly healthy trees may lose vigor and eventually die. What does a Spongy Moth look like? Their egg masses are tan, teardrop-shaped and approximately 1 1/2″ long. Their larvae, or caterpillars, are about ¼” long and are black or brown. As they grow they develop black hairs and colored spots and can reach a length of up to 2 ½”. Adult spongy moths appear in mid-summer. The males are brown, have feathery antennae and can fly. The females are cream-colored and cannot fly. Spongy moth caterpillars feed on virtually any type of tree, including: Oak tree Elm tree Maple tree Apple tree Alder tree Birch tree Willow tree Pine trees Spruce tree Sweetgum tree Aspen tree Basswood tree Hemlock tree The Spongy Moth Caterpillar Problem Spongy moth caterpillars are voracious eaters. They defoliate millions of acres of trees annually. When they hatch, they feed (mostly nocturnally) on the leaves of trees and shrubs. They can completely defoliate an entire tree in one season. Even a partial defoliation can severely stress a tree, putting it at risk for secondary pests or diseases. Depending on the type of tree and its health, defoliation or repeat defoliation can significantly weaken or even kill the tree. Extreme defoliation can kill a low vigor tree after one year. Signs of Spongy Moth Infestation Egg masses on tree trunks, outdoor furniture, swing sets, yard tools, lumber and the sides of dwellings Caterpillar sightings in late spring Holes in leaves Defoliation Spongy Moth Treatment and Control Options The best way to avoid damage is to keep your trees healthy. A strong and vigorous tree is better able to naturally resist attack and survive a infestation. SavATree’s methods include regular fertilization and pruning, as well as insect treatment if necessary, protecting your precious trees against this highly destructive pest. Contact us today to schedule a consultation with an expert arborist.