Household Casebearer, Plaster Bagworm
Scientific Name: Phereoeca uterella
Order & Family: Lepidoptera (Moths and Butterflies), Tineidae (Fungus and Clothes Moths)
Size: Larval cases are typically 8-15 mm (0.3-0.6 inches) long. The larva itself is smaller, and the adult moth has a wingspan of about 10-14 mm (0.4-0.55 inches).
Natural Habitat
Typically found indoors in undisturbed areas with accumulated dust and debris, such as under furniture, in closets, attics, garages, and basements. They thrive in humid conditions.
Diet & Feeding
The larvae feed on a wide variety of organic materials found in homes, including wool, silk, hair, felt, lint, dust, cobwebs, and fabrics made from natural fibers. They are scavengers.
Behavior Patterns
Larvae construct a case out of silk and surrounding debris (like sand, lint, fabric fibers, or detritus) which they carry with them. They are slow-moving and retreat into their case if disturbed. Adults are winged but often weak fliers and short-lived.
Risks & Benefits
Potential risks include damage to natural fiber textiles, carpets, and stored goods. They are not known to bite or carry diseases beneficial to humans. In small numbers, they are part of the natural breakdown of organic matter.
Identified on: 8/10/2025