Plaster Bagworm (or Household Casebearer)
Scientific Name: Phereoeca uterella (or sometimes its close relative, Praececodes atomosella)
Order & Family: Order: Lepidoptera, Family: Tineidae (Clothes Moths)
Size: Larval case is typically 8-13 mm (0.3-0.5 inches) long.
Natural Habitat
Commonly found indoors on walls, in corners, closets, or underneath spiderwebs. They thrive in humid environments like Florida and tropical regions.
Diet & Feeding
Larvae feed on keratin and detritus, including spider webs, old insect skins, wool, hair, and sometimes natural fibers in carpets and clothing.
Behavior Patterns
The larva builds a flattened, pumpkin-seed-shaped case out of silk and debris (sand, dust, bug parts) which it carries around for protection. The larva has openings at both ends of the case, allowing it to turn around inside and feed from either end.
Risks & Benefits
Generally considered a nuisance pest rather than a major threat. They do not bite or sting humans. While they can feed on wool and natural fabrics, they rarely cause significant damage unless present in large numbers. They can help clean up dead insect parts and spider webs.
Identified on: 2/12/2026