Household Casebearer or Plaster Bagworm

Natural Habitat

Commonly found indoors in homes, warehouses, and other buildings, particularly in damp or humid areas such as bathrooms, kitchens, and basements. They can also be found outdoors in sheltered, dark places.

Diet & Feeding

Larvae feed on a variety of organic materials including wool, silk, hair, pet fur, lint, dust, cobwebs, and sometimes synthetic fibers. They may also consume dead insects and spiders, or fungi and mildew.

Behavior Patterns

The most distinctive behavior is the larvae's construction and use of a portable, silken case covered with substrate particles (dust, lint, debris), which they carry with them. They move by extending their head and legs from one end of the case. They are typically slow-moving and prefer dark, undisturbed areas. Adults are small, dark moths that are weak fliers and rarely seen.

Risks & Benefits

Risks: Primarily a nuisance pest in homes. They can cause damage to natural fiber products like wool carpets, clothing, and upholstered furniture, though usually less severe than clothes moths. They are not known to bite or transmit diseases. Benefits: None significant to humans, but as detritivores, they contribute to the breakdown of organic matter.

Identified on: 9/22/2025