Household Casebearer (often confused with Plaster Bagworm)
Scientific Name: Phereoeca uterella / Phereoeca allutella
Order & Family: Order: Lepidoptera, Family: Tineidae
Size: Larval case is typically 8-13 mm long
Natural Habitat
Commonly found indoors on walls, in dusty corners, closets, and along baseboards. They thrive in warm, humid climates.
Diet & Feeding
The larvae feed on old spider webs, wool, hair, lint, dried insect parts, and general household dust.
Behavior Patterns
The larva builds a protective, flattened, almond-shaped case out of silk and camouflages it with debris like sand, soil, and fiber. It drags this case around as it moves. When threatened, it retreats inside openings at either end.
Risks & Benefits
Generally harmless to humans and does not bite or sting. However, they can be a minor nuisance pest that damages natural fibers like wool or silk if present in large numbers. Benefit: They clean up minor debris and old spider webs.
Identified on: 2/9/2026