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Emilie Bess and Kevin P. Johnson
Containing group: Homilopsocidea


The family Trichopsocidae contains 9 species in the genus Trichopsocus distributed worldwide, but absent from Asia. Two species are known from North America; Trichopsocus acuminatus, introduced from Europe, and T. dalii, introduced from Italy, Peru, and Mexico.

These are medium-sized bark lice (2-2.5 mm, nymphs also 2-2.5 mm) with slender bodies.  Body color is yellow. Trichopsocids inhabit leaves on living and dead trees.



General Characters

How to Know the Family

Family Monophyly

Monophyly of the family Trichopsocidae is supported by the secondary loss of the distal extension of the subgenital plate in the female (Yoshizawa 2002). The morphological variation within this small family is not well known.

Discussion of Phylogenetic Relationships

Relationships within the family have not been investigated using molecular techniques.

Other Names for Trichopsocus


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

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.

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. Trichopsocidae. Trichopsocus. Version 25 March 2009 (under construction). http://tolweb.org/Trichopsocus/14476/2009.03.25 in The Tree of Life Web Project, http://tolweb.org/

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