Plaster Bagworm (or Household Casebearer)
Scientific Name: Phereoeca uterella
Order & Family: Lepidoptera (Order), Tineidae (Family)
Size: Larval case is about 8-13 mm (0.3-0.5 inches) long.
Natural Habitat
Typically found indoors in warm, humid climates; often seen on stucco walls, under furniture, in garages, or on carpets and wool fabrics.
Diet & Feeding
The larvae feed on silk, spider webs, wool, lint, hair, and other organic debris found in households.
Behavior Patterns
The larva constructs a protective flat, pumpkin-seed-shaped case made of silk and camouflaged with sand, dust, and soil particles. It drags this case around as it feeds, retreating inside when threatened. It has a complete metamorphosis life cycle.
Risks & Benefits
Generally harmless to humans (does not bite or sting). Considered a minor household pest because they can damage woolen fabrics, rugs, or clothing, though they primarily feed on spider webs and loose debris.
Identified on: 2/27/2026