WSU Extension


Food and Fabric
Carpet beetles
Casemaking clothes moth
Cupboard beetle
Drugstore beetle
Indian meal moth
Mediterranean flour moth
Mites in stored foods
Psocids (booklice or barklice)
Sawtooth grain beetle
Spider beetle
Whiteshouldered house moth

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Caption: Psocids (booklice or barklice)
Photo by: Ken Grey
Psocids (booklice or barklice)
(revision date: 7/14/2015)

Use Integrated Pest Management (IPM) for successful pest management.

Psocids are small insects, usually 1/16 to 1/8 inch long. While sometimes called booklice or barklice, psocids are not lice. Some psocids are winged as adults, while other species may be wingless. Some of the wingless types can be pests of stored food such as flour, sugar, or cereal and some will attack the glue of book bindings. Many species in nature are beneficial scavengers feeding on dead insects. Many others feed on pollen, fungi, lichens, and mold. Psocids are generally white, pale cream-colored, light gray or dark gray in color. They are elongate-oval in shape, and have chewing mouthparts and fairly long threadlike antennae. Those species that cause problems in stored foods favor damp, dark, and warm habitats that are relatively undisturbed. Under favorable conditions, these prolific insects can exceed six generations a year.
Management Options

Non-Chemical Management
  • Maintain a good level of sanitation. Clean up spilled or exposed food and vacuum and clean food debris from cracks and corners of storage areas.
  • Buy dry-good foods in quantities that will be used in a few months. Food in long-term storage is more vulnerable to infestation.
  • Pests can get into most cardboard and light plastic packaging, so store food in tightly-sealed containers of heavy plastic, glass, or other tough materials if it is not going to be used in the near future.
  • If these pests are discovered, locate the source and get rid of it. Examine other products in the vicinity to see if they’ve spread. Dispose of infested food to prevent further spread.
Select non-chemical management options as your first choice!

Chemical Management

None recommended.


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Caption: Psocids (booklice or barklice)
Photo by: Ken Grey