Booklice
Howard Russell, Sarah Hughson
Print
EmailBooklice (Order: Pscoptera)
Booklice are found throughout the world in damp and secluded places where they feed on molds and mildews. Booklice are not true lice. Although they resemble immature human lice, they are not parasitic. They are harmless except for contamination of foods and they are nuisances merely by their presence in the homes, food storage and processing buildings, and other structures. Booklice can be found throughout structures but are normally confined to damp areas such as basements which foster a growth of mold and mildew. They can be very numerous if books and papers, which are very susceptible to mold growth, are stored in these areas. Booklice can be serious pests of stored foods under excessively damp conditions as well. Booklice are very susceptible to changes in relative humidity: if the home or building can be maintained at RH of 50%, booklice will die out in 2 to 3 weeks. In the late fall and winter, when humidity is lower and heaters are running, their populations decline and pesticide applications are not necessary. Home-infesting booklice can complete their life cycle in about a month at 80 degrees. Any household insecticide containing pyrethrins (like Raid) will provide temporary control.
Closely follow the directions for use on the pesticide label for a safe and effective application. Ensure that the pesticide label indicates that it is for indoor use and for controlling booklice.
Original article by Howard Russell
Article reviewed by Sarah Hughson, May 2025