Mesopsocidae

Definition

A family of small, scavenging barklice and booklice (order Psocodea, suborder Psocomorpha) distinguished by a free areola postica—an unbranched, looped anal vein in the hindwing that is not connected to other veins by crossveins. The family comprises more than 70 described species, most inhabiting bark, leaf litter, or foliage where they feed on microfungi, algae, and detritus.

Etymology

From Greek mesos (middle) + Psocidae (type family of Psocodea), referring to intermediate or central systematic position among psocid families.

Example

Mesopsocus unipunctatus, a common European species in Mesopsocidae, can be identified in the field by its unmarked pale wings and the diagnostic free areola postica visible under magnification.

Related Terms

• Psocodea
• Psocomorpha
• areola postica
• Psocidae
• barklice
• booklice

Usage Notes

The free areola postica is the key diagnostic wing character separating Mesopsocidae from related families such as Psocidae, where the areola is typically joined to the media by a crossvein. Species identification within the family relies heavily on genitalic and wing-venation characters; many are cryptic in coloration and require microscopic examination.