Household Casebearer (or Plaster Bagworm)
Scientific Name: Phereoeca uterella
Order & Family: Order: Lepidoptera, Family: Tineidae
Size: Larval case is typically 8 mm to 13 mm in length.
Natural Habitat
Commonly found inside homes in humid climates, often on walls, baseboards, or under spiderwebs in corners. They originate from tropical and subtropical areas.
Diet & Feeding
The larvae feed on old spider webs, silk, wool (though less commonly than clothes moths), and debris like human hair or dead insect parts.
Behavior Patterns
The larva constructs a flattened, pumpkin-seed-shaped protective case out of silk and debris (sand, soil, paint chips) which it carries around. It can turn around inside the case to feed from either end. When ready to pupate, it attaches the case to a vertical surface.
Risks & Benefits
Generally considered a harmless nuisance pest. They do not bite or sting humans. While they can feed on wool fibers, they are not major fabric pests compared to true clothes moths. They help clean up minor debris like spider webs.
Identified on: 3/5/2026