Phereoeca uterella (Household Casebearer or Plaster Bagworm)

Natural Habitat

Typically found indoors in humid climates, often in garages, closets, and underneath furniture. They prefer dark, undisturbed areas with high humidity.

Diet & Feeding

Larvae feed on spider webs, old silk casings, wool, lint, hair, and other keratin-containing materials or detritus.

Behavior Patterns

The larva constructs a protective, flattened, pumpkin-seed-shaped case out of silk and environmental debris (dust, sand, fiber). It carries this case around and can retract inside when threatened. It eventually pupates inside the case to become a small moth.

Risks & Benefits

Generally harmless to humans (does not bite or sting). Can be a minor pest if they damage wool or fabrics, but usually feed on debris. Their presence often indicates high humidity or dusty conditions.

Identified on: 2/26/2026