Under Construction


Emilie Bess and Kevin P. Johnson
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
taxon links [up-->]Orbiperipsocus [up-->]Coniperipsocus [up-->]Bicuspidatus [up-->]Turriperipsocus [up-->]Campanulatus [up-->]Pericupsocus [up-->]Periterminalis [up-->]Peripsocus [up-->]Diplopsocus [up-->]Cycloperipsocus [up-->]Kaestneriella [up-->]Properipsocus [down<--]Homilopsocidea Interpreting the tree
close box

This tree diagram shows the relationships between several groups of organisms.

The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.

example of a tree diagram

You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.

For more information on ToL tree formatting, please see Interpreting the Tree or Classification. To learn more about phylogenetic trees, please visit our Phylogenetic Biology pages.

close box
Containing group: Homilopsocidea


The family Peripsocidae contains about 235 species in 12 genera distributed worldwide, with highest diversity in Asia.  Thirteen species are known from North America in the genera Peripsocus and Kaestneriella.

Peripsocids are medium-sized bark lice (2-4 mm, nymphs 2-2.5 mm) with robust bodies.  Body color is dusky brown. Peripsocids inhabit bark of trees and shrubs and rock surfaces.  Some species are sexually dimporphic (different body forms in male and female) or polymorphic (different body forms within a sex).



General Characters

How to Know the Family

Discussion of Phylogenetic Relationships

Monophyly of family Peripsocidae is well supported by two morphological characters: absence of the areola postica in the forewing and, in the male, a strap-like paramere on the phallosome (Yoshizawa 2002).   Molecular data also support the monophyly of the family based on the sister relationship of genera Peripsocus and Kaestneriella (18S nDNA  and 12S, 16S, COI mtDNA, Johnson & Mockford 2003; 18S nDNA, Johnson et al 2004), but relationships within the family have not been studied further with molecular techniques.


Johnson, K. P. & E. L. Mockford. 2003. Molecular Systematics of Psocomorpha (Psocoptera). Systematic Entomology 28: 409-40.

Johnson, K. P., K. Yoshizawa, and V. S. Smith. 2004. Multiple origins of parasitism in lice. Proceedings of the Royal Society of London B 271:1771-1776.

Lienhard, C. and C. N Smithers. 2002. Psocoptera (Insecta) World Catalogue and Bibliography. Muséum d'Histoire Naturelle, Geneva, Switzerland.

Mockford, E. L. 1993. North American Psocoptera (Insecta). Gainesville, Florida: Sandhill Crane Press.

New, T.R. 2005. Psocids, Psocoptera (Booklice and barklice), 2nd edition: Handbooks for the Identification of British Insects. Vol. 1, Part 7. Royal Entomological Society, London, UK.

Smithers, C. N. 1996. Psocoptera. Pp. 1-80, 363-372 (Index) in Wells A. (ed.) Zoological Catalogue of Australia. Vol. 26. Psocoptera, Phthiraptera, Thysanoptera. Melbourne: CSIRO Publishing, Australia.

Yoshizawa, K. 2002. Phylogeny and higher classification of suborder Psocomorpha (Insecta: Psocodea:'Psocoptera'). Zoological Journal of the Linnean Society 136: 371-400.

Title Illustrations
Click on an image to view larger version & data in a new window
Click on an image to view larger version & data in a new window
Scientific Name Peripsocus sp.
Location Japan
Specimen Condition Live Specimen
Identified By K. Yoshizawa
Life Cycle Stage adult
View lateral
Size 3mm
Copyright © 2006 Kazunori Yoshizawa
Scientific Name Peripsocus
Location Groton, Ma.
Comments 10/3/2007
Specimen Condition Live Specimen
Life Cycle Stage adult
View lateral
Copyright © Tom Murray
About This Page

Emilie Bess
Illinois Natural History Survey, Champaign, Illinois, USA

Kevin P. Johnson
Illinois Natural History Survey, Champaign, Illinois, USA

Correspondence regarding this page should be directed to Emilie Bess at and Kevin P. Johnson at

All Rights Reserved.

Citing this page:

Bess, Emilie and Kevin P. Johnson. 2009. Peripsocidae. Version 25 March 2009 (under construction). http://tolweb.org/Peripsocidae/14473/2009.03.25 in The Tree of Life Web Project, http://tolweb.org/

edit this page
close box

This page is a Tree of Life Branch Page.

Each ToL branch page provides a synopsis of the characteristics of a group of organisms representing a branch of the Tree of Life. The major distinction between a branch and a leaf of the Tree of Life is that each branch can be further subdivided into descendent branches, that is, subgroups representing distinct genetic lineages.

For a more detailed explanation of the different ToL page types, have a look at the Structure of the Tree of Life page.

close box


Page Content

articles & notes



Explore Other Groups

random page

  go to the Tree of Life home page