Lappet moths

Definition

A common name for moths of the family Lasiocampidae (superfamily Lasiocampoidea), characterized by larvae with fleshy, flap-like abdominal prolegs (lappets) that aid in clinging to vegetation. Adults are typically stout-bodied with densely hairy thoraxes; larvae are often gregarious, constructing silken tents or feeding in clusters. The family includes economically significant forest pests such as tent caterpillars (Malacosoma spp.) and eggars.

Etymology

From the lobe-like lappets on the abdominal prolegs of larvae; 'moth' from Old English moththe.

Example

The eastern tent caterpillar (Malacosoma americanum), a lappet moth, forms conspicuous silken tents in cherry and apple trees and can cause significant defoliation in outbreak years.

Synonyms

• eggars
• tent caterpillar moths
• snout moths

Related Terms

• Lasiocampidae
• Tent caterpillars
• Malacosoma
• Proleg
• lappet
• gregarious larvae
• silken tent
• forest Lepidoptera

Usage Notes

The name 'lappet moths' refers specifically to Lasiocampidae, though 'lappet' also describes similar fleshy projections in other larval insects. Not to be confused with Anthelidae (Australian lappet moths), a separate family with convergent larval morphology. 'Eggars' and 'snout moths' are also applied to this family but are less precise; 'tent caterpillar moths' emphasizes the larval habit. Adults are nocturnal and non-feeding in many species.