Household Casebearer (also known as the Plaster Bagworm or Phereoeca)

Natural Habitat

Typically found indoors in humid conditions, attaching to walls, baseboards, carpets, and hidden corners. They are common in homes, garages, and underneath furniture.

Diet & Feeding

The larvae feed on keratin and detritus, including spider webs, old insect skins, wool, human hair, pet fur, and sometimes natural fabrics.

Behavior Patterns

The larva constructs a distinctive flat, pumpkin-seed shaped case out of silk and debris (sand, soil, frass, and fiber). It lives inside this case, dragging it along as it moves. The larva can extend its head and legs from either end of the case to feed or move. When ready to pupate, it attaches the case to a vertical surface.

Risks & Benefits

Risks: Generally considered a nuisance pest rather than a dangerous one. They do not bite or sting humans. However, in large numbers, they can cause minor damage to woolens, rugs, or fabrics. Benefits: They act as minor cleaners by consuming old spider webs and dead insects, though this benefit is usually outweighed by their status as a household pest.

Identified on: 3/8/2026