Booklice & Psocids - School IPM - USU Extension

    Booklice and Psocids



    Booklice (Tony Willis, Wikimedia Commons)


    Booklice (David Sheltar, Ohio State University,


    Barklice (Wikimedia Commons)


    • minute: 1/25 - 1/13 inch long
    • booklice found outdoors may be larger, up to 1/4 inch
    • very common in pest monitors; look like small specks (use hand lens to identify)
    • may have wings or not
    • other species of psocids are called barklice

    Nesting Habits

    • prefer warm, humid or damp places
    • can be found around damp books, around leaking/sweating pipes, in voids, in cardboard boxes or anywhere where mold growth can be supported
    • barklice live outdoors on/under bark, grass, leaves, damp wood, etc.


    • mold spores
    • may feed on fungal spores on stored food products


    • nuisance pest indoors
    • indicator of moisture issues

    IPM Recommendations

    • Reduce relative humidity within trouble areas.
    • Vacuum.
    • Remove leaf litter from around the exterior of structures.
    • Store food items in pest-proof containers.

    Additional Resources:

    Booklice and Their Relatives fact sheet

    IPM for Silverfish, Firebrats, and Booklice: Integrated Pest Management in Sensitive Environments (University of Nebraska-Lincoln Extension)