Household Casebearer or Plaster Bagworm

Scientific Name: Phereoeca uterella

Order & Family: Order: Lepidoptera, Family: Tineidae

Size: Larval case is approximately 8-13 mm long

Household Casebearer or Plaster Bagworm

Natural Habitat

Typically found indoors in dry, dusty areas such as baseboards, closets, corners, under furniture, and in garages. They thrive in humid climates.

Diet & Feeding

The larvae feed on old spider webs, wool, hair, lint, and dead insects.

Behavior Patterns

The larva constructs a flattened, pumpkin-seed-shaped case made of silk and debris (like sand, paint fragments, or bug parts) that it carries around for protection. It stays inside this case, protruding its head to eat and move.

Risks & Benefits

Generally considered a nuisance pest rather than a major threat. They do not bite or sting humans, but they can damage wool clothing or rugs if infestations are severe. They are beneficial in a minor way as they clean up cobwebs and dead insects.

Identified on: 3/8/2026