Household Casebearer (often confused with Plaster Bagworm)
Scientific Name: Phereoeca uterella (sometimes referred to as Phereoeca allutella in older texts)
Order & Family: Lepidoptera order, Tineidae family (Clothes Moths)
Size: The case itself is usually about 7–13 mm (0.25–0.5 inches) in length. The larva inside is slightly smaller.
Natural Habitat
Typically found indoors in climate-controlled environments like homes, garages, and closets, particularly in humid regions. They are often seen on stucco walls, under furniture, or in corners where dust accumulates.
Diet & Feeding
They feed on old spider webs (contains insect remains), wool, hair, lint, and other keratin-based fibers found in household dust.
Behavior Patterns
The larva constructs a flattened, pumpkin-seed-shaped protective case made of silk and camouflaged with sand, soil, lint, and debris. It drags this case along as it moves. The larva has openings at both ends of the case, allowing it to turn around inside and feed from either end without leaving its protection.
Risks & Benefits
Risks: Generally considered a harmless nuisance rather than a major pest. They do not bite or sting. However, in large numbers, they can cause minor damage to woolens or carpets. Benefits: Minimal, though they do consume old spider webs and dust bunnies.
Identified on: 3/6/2026