Household Casebearer (often locally called 'Plaster Bagworm')

Scientific Name: Phereoeca uterella

Order & Family: Order: Lepidoptera, Family: Tineidae

Size: Larval case is usually 8–13 mm long (approx. 0.3–0.5 inches)

Household Casebearer (often locally called 'Plaster Bagworm')

Natural Habitat

Typically found indoors in humid climates, often on walls, baseboards, or under furniture. They construct a protective case out of silk and available debris (dust, lint, etc.) which they carry around.

Diet & Feeding

The larvae feed on keratin-containing materials such as wool, hair, and spider webs. They will also eat other small insects and general household detritus.

Behavior Patterns

The most distinctive behavior is carrying a flat, pumpkin-seed-shaped case made of silk and debris. The larva lives inside this case and drags it along as it moves. The case has openings at both ends so the larva can turn around inside without leaving.

Risks & Benefits

Generally considered a minor pest rather than a health risk; they do not bite or sting humans. However, in large numbers, they can cause damage to wool clothing, rugs, or tapestries.

Identified on: 2/18/2026