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Eastern Tent Caterpillar (Malacosoma american)

Tent caterpillar silk web mass in a treeEastern tent caterpillar egg mass on a stickEastern tent caterpillar

Adult moths are about 1 inch long. They are light brown with two white diagonal stripes across each forewing. Mature larvae (B) may reach a length of 2 inches or more. This is the only common caterpillar with a white stripe down the back. There is one generation a year. Pupae overwinter in cocoons in debris on the ground.

Silken webs in tree forks at budbreak are indicative of this pest. In peak population years, preferred hosts can be defoliated.

Look for the black 3/4 inch-long egg masses on preferred hosts in the dormant season. Look for silken webs in the branch forks of preferred hosts in early March.

Prune out the egg masses during the dormant season. Mechanically destroy the web contents when first discovered. Time insecticide application for the presence of young larvae.