Household Casebearer or Plaster Bagworm
Scientific Name: Phereoeca uterella (or sometimes Phereoeca allutella)
Order & Family: Order: Lepidoptera, Family: Tineidae
Size: Larval case is typically 8-13 mm (approx. 0.3-0.5 inches) in length.
Natural Habitat
Typically found indoors in humid climates, often seen on walls, in corners, closets, or on fabrics like wool and rugs.
Diet & Feeding
The larvae feed on keratin-found in wool, hair, and fur-as well as spider webs, insect debris, and old plaster or paint.
Behavior Patterns
The larva constructs a distinctive flattened, pumpkin-seed-shaped case out of silk and debris (sand, soil, fibers), which it drags along as it moves. The larva lives inside this protective case and can turn around inside to feed from either end.
Risks & Benefits
Generally considered a minor household pest. While harmless to humans (they do not bite or sting), they can cause minor damage to woolen fabrics, rugs, or furs if present in large numbers.
Identified on: 2/19/2026