Plaster Bagworm (or Household Casebearer)

Natural Habitat

Commonly found inside homes in humid climates, often on walls, ceilings, and in closets. They create a protective case from silk, sand, and debris that resembles a pumpkin seed or plaster spot.

Diet & Feeding

The larvae feed on spider webs, old silk, woolen fibers, dead insects, and general household dust and lint.

Behavior Patterns

The larva drags its protective case around with it as it moves. It can feed from either end of the case. When it is ready to pupate, it attaches the case to a vertical surface (like a wall) or hangs from a horizontal one.

Risks & Benefits

They are generally harmless to humans and do not bite or sting. However, they can be considered household pests because they may eat natural fibers like wool or silk, potentially damaging clothing or rugs. They are beneficial in that they clean up spider webs and dead insects.

Identified on: 2/27/2026