Household Casebearer or Plaster Bagworm
Scientific Name: Phereoeca uterella (sometimes referred to as Phereoeca allutella)
Order & Family: Order: Lepidoptera, Family: Tineidae
Size: Larvae are roughly 8-13 mm (0.3-0.5 inches) long inside the case.
Natural Habitat
Typically found indoors in humid climates, often on walls, baseboards, or under furniture. They construct silken cases covered in debris to camouflage themselves.
Diet & Feeding
Detritivores that feed on old spider webs, wool, hair, lint, dead insects, and dried animal remains.
Behavior Patterns
The larva drags its protective, pumpkin-seed-shaped case around with it as it moves. The case is open at both ends, allowing the larva to turn around inside and feed from either end. When threatened, it retracts completely into the shell.
Risks & Benefits
Generally harmless to humans and pets as they do not bite or sting. However, they can be considered a minor pest because they feed on natural fibers like wool and silk, potentially damaging clothing or rugs.
Identified on: 2/8/2026