Tent caterpillars

Definition

Gregarious caterpillars in the genus Malacosoma (family Lasiocampidae) that construct conspicuous silken tent structures in the forks of host-tree branches, within which they aggregate for thermoregulation and group defense. Unlike solitary caterpillars, tent caterpillars exhibit cooperative foraging behavior, departing en masse from the tent to feed on foliage and returning to the communal shelter.

Etymology

From the silken tent structure built and occupied by the larvae; 'caterpillar' from Middle English catirpel/catirpeller, perhaps influenced by Latin pilosus (hairy).

Example

Eastern tent caterpillars (Malacosoma americanum) build their tents in black cherry and other Rosaceae hosts, with larvae huddling inside on cool mornings to elevate body temperature before emerging to feed.

Synonyms

• Malacosoma larvae

Related Terms

• gregarious behavior
• silken nest
• Thermoregulation
• Lasiocampidae
• processionary caterpillars
• defensive aggregation

Usage Notes

The term refers specifically to Malacosoma species; other tent-building caterpillars (e.g., fall webworms, Hyphantria cunea, which build enclosed webs at branch tips rather than forked tents) are not true tent caterpillars. The common name is sometimes applied loosely to any communal tent-building larva, but specialists reserve it for Malacosoma. Distinguish from 'armyworm' behavior, which involves progressive migration without fixed shelter.