Household Casebearer (often called Plaster Bagworm)
Scientific Name: Phereoeca uterella
Order & Family: Order: Lepidoptera, Family: Tineidae (Clothes Moths)
Size: Case typically 8–13 mm long
Natural Habitat
Typically found indoors in warm, humid climates; often seen on walls, in corners, crevices, or underneath furniture in garages and bathrooms.
Diet & Feeding
Detritivore feeding on spider webs, old insect cocoon/cast skins, woolen fibers, and human hair.
Behavior Patterns
The larva constructs a flattened, pumpkin-seed-shaped protective case out of silk and debris (sand, dust, fibers) which it carries around. It has openings at both ends, allowing the larva to turn around inside and feed from either end.
Risks & Benefits
Generally harmless to humans (does not bite or sting). Can be a minor pest if populations are large, as they may feed on woolen fabrics or rugs, similar to other clothes moths, but usually they are just a nuisance feeding on dust and spider webs.
Identified on: 3/1/2026