Common name(s): psocids, booklice, barklice
Description: Small in size (1mm to 7mm), the head is large and mobile. The compound eyes are large. Antennae are long and slender. Wings are reduced or absent: if present, venation is simple and they are held roof-like over the back at rest. Their mouthparts are highly specialized. They have asymmetrical chewing mandibles, rod-shaped maxillary laciniae, and reduced labial palps. Cerci are absent. Immature nymphs look like small adults; development is hemimetabolous.
Fun facts: Psocoptera exist worldwide, cryptic and small. There are over 3000 species in 35 families. Courtship often involves a mating dance. Eggs are laid singly or in groups, onto vegetation or under bark. Parthenogenesis is common, and may be obligatory or facultative. Vivipary is known in at least one genus.
Some species are solitary, while others are communal, forming small groups of adults and nymphs. Adults and nymphs feed on fungi, lichens, algae and planet debris. Booklice, which are the species of Psocoptera that live indoors, are an indication of how insects have changed their feeding habits as humans developed; they are wingless and eat the paste of bookbindings, glues, starch, grain and cereal products. These species are pests to humans.
Psocoptera is the sister order to Mallophaga (chewing lice) and Anoplura (sucking lice). Together these are collectively known at the Psocodea, and are part of the Hemipteroid orders.
sourced, in part, by The Insects: An outline of entomology, second ed. Gullan, P.J. and P.S. Cranston. Blackwell Science, Great Britain, 2000.