Household Casebearer (often specifically the Plaster Bagworm or similar)
Scientific Name: Phereoeca uterella (or related Tineidae species)
Order & Family: Lepidoptera (Order) / Tineidae (Family)
Size: Larval cases are usually 8-13 mm (0.3-0.5 inches) in length.
Natural Habitat
Typically found indoors in humid climates, often in corners, closets, under furniture, or on stucco walls. They thrive in areas with spider webs or accumulated dust.
Diet & Feeding
Detritivores; they feed on spider webs, old insect skins, wool, hair, and other organic debris found in dust.
Behavior Patterns
The larva constructs a protective, flattened, pumpkin-seed-shaped case out of silk and debris (sand, soil, lint) which it carries around. It can emerge from either end of the case to move or feed.
Risks & Benefits
Generally harmless to humans and pets (they do not bite or sting). They can be a minor nuisance pest in homes because their cases are unsightly on walls, but they may provide a small benefit by eating spider webs and dust.
Identified on: 2/8/2026