Plaster Bagworm (or Household Casebearer)
Scientific Name: Phereoeca uterella
Order & Family: Order: Lepidoptera, Family: Tineidae
Size: Larval case is typically about 8–13 mm (0.3–0.5 inches) long.
Natural Habitat
Typically found indoors in dry areas, hanging on walls, ceilings, baseboards, or underneath furniture. They are common in humid climates like Florida.
Diet & Feeding
The larvae feed on detritus, cobwebs, old spider webs, wool, and other natural fibers found in household dust.
Behavior Patterns
The larva constructs a protective case (visible in the image) from silk and debris like sand, soil, and insect parts. It drags this case around as it moves. It is shaped like a pumpkin seed or a flattened spindle, with openings at both ends so the larva can turn around inside.
Risks & Benefits
They are generally considered a nuisance pest rather than dangerous. They do not bite or sting humans. However, in large numbers, they may damage fabrics like wool or silk.
Identified on: 2/14/2026