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-->]Psoquillidae [up-->]Trogiidae [up-->]Lepidopsocidae [down<--]Trogiomorpha 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: Trogiomorpha


Infraorder Atropetae includes families Lepidopsocidae, Psoquillidae, and Trogiidae and comprises 31 genera and about 300 species distributed worldwide.  The North American fauna includes 25 species from 13 genera.



General Characters

Discussion of Phylogenetic Relationships

Monophyly of infraorder Atropetae is supported by two characters of the female genitalia: the ovipostior composed of the elongated external valves of the gonapophyses joined together at midline by a membrane, and the presence of glandular accessory bodies in the spermathecal sac.  Molecular analysis of nine species of Atropeae also supports the monophyly of the infraorder and indicates a sister relationship between families Trogiidae and Psoquillidae (genes 18S & Histone3 nDNA, 16S rDNA; Yoshizawa et al. 2006).


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.

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.

Smithers, C.N. 1972. The classification and phylogeny of the Psocoptera. Memoirs of the Australian Museum 14: 1–349.

Yoshizawa, K., C. Lienhard, and K.P. Johnson. 2006. Molecular systematics of the suborder Trogiomorpha (Insecta: Psocodea: ‘Psocoptera’). Zoological Journal of the Linnean Society 146: 287–299.

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 Echmepteryx hageni
Location Dixville, N.H.
Comments 10/9/2007
Specimen Condition Live Specimen
Life Cycle Stage adult
View dorsal
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. Atropetae. Version 18 March 2009 (under construction). http://tolweb.org/Atropetae/30214/2009.03.18 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