Barklice Psocids and Book Lice: Psocoptera

Physical characteristics: Book lice are small, about 0.04 inches (1 millimeter) in length. They are wingless, somewhat flattened, and are pale brown in color. Each compound eye is made up of seven lenses.

Geographic range: They are found on all continents.

Habitat: Book lice are commonly found in homes and businesses where foods are stored. They also occur in the wild in the nests of birds and other animals.

Diet: They eat funguses and other bits of plant and animal materials.

Behavior and reproduction: Different populations vary in size, color, egg production, and tolerance to insecticides.

Reproduction is by parthenogenesis only. Eggs are laid singly or in small batches and covered with a powdery dust. The larvae molt four times before reaching adulthood.

Book lice are considered a nuisance when they infest stored foods and libraries. Their presence in the home may also set off allergy and asthma attacks. (Illustration by Barbara Duperron. Reproduced by permission.)

Book lice and people: Book lice are considered a nuisance when they infest stored foods and libraries. Their presence in the home may also set off allergy and asthma attacks.

Conservation status: This species is not endangered or threatened. ∎