Bug Identifier
Eastern Tent Caterpillar
Community identification

Eastern Tent Caterpillar

Malacosoma americanum

Order & Family
Order: Lepidoptera, Family: Lasiocampidae
Size
Larvae (caterpillars) typically reach 4-5 cm (1.5-2 inches) in length when fully grown. Adult moths have a wingspan of 3-4 cm (1.2-1.6 inches).
See this bug in the Encyclopedia

Natural Habitat

Eastern Tent Caterpillars are commonly found in deciduous forests, woodlands, orchards, and suburban areas where their host trees are present. Their silken tents are conspicuous on branches.

Diet & Feeding

The caterpillars are herbivores, feeding primarily on the leaves of various deciduous trees and shrubs, including those of cherry, apple, crabapple, and plum trees. They can also feed on beech, birch, ash, maple, oak, and willow.

Behavior Patterns

Eastern Tent Caterpillars are social during their larval stage, living communally in silken tents that they construct in the crotches of trees. They emerge from the tent to feed on leaves, often in columns, and return to the tent for shelter, especially during cooler temperatures or at night. They are active during the day. The adult moths are nocturnal. Larvae overwinter as embryos within eggs laid on host trees.

Risks & Benefits

Risks: Eastern Tent Caterpillars can cause significant defoliation of host trees during outbreaks, which can weaken trees, reduce fruit production in orchards, and make trees more susceptible to other stressors. Their hairs can cause skin irritation in some sensitive individuals. Benefits: They serve as a food source for various birds, parasitic wasps, and predatory insects. They are also part of the natural forest ecosystem and cycles of defoliation and recovery.