Archipsocidae

Introduction

The family Archipsocidae contains about 80 species in 5 genera distributed worldwide, with highest diversity in Central and South America.  Seven species are known from North America in the genera Archipsocus, Archipsocopsis and Pararchipsocus.

These are small to medium-sized bark lice (1-3 mm, nymphs 1.5-2.5 mm).  Body colors are red- or orange-brown, sometimes pale. Almost all body surfaces are densely covered with long hairs. Wings are creamy white.  Archipsocids live on the surface of bark, often in groups under dense webs, and subsocial behavior has been observed in some species.

Morphological and molecular data both suggest that Archipsocidae is sister to the remainder of suborder Psocomorpha.  The family has been placed in its own infraorder, Archipsocetae (Yoshizawa 2002, Johnson et al. 2004).

Characteristics

Synapomorphies

• Leg: pretarsal claw lacks a preapical tooth.
• Forewings:
• Forewing veins and membrane are covered with long hairs.
• Hairs on forewing margin form crossing pairs.
• Forewings have reduced venation.
• Male: parameres are reduced and membranous.
• Female: gonapophyses lacks a ventral valve.
• Behavior: All known species of this family live in groups on bark or dead leaves beneath sheets of webbing.  Subsociality has been documented in Archipsocidae.
  

General Characters

• Head: 
  
• Antennae have 13 segments.
• Antennae are hairy.
• Leg:    Tarsi have 2 segments.    
• Wings:    
  
• Most species have short-winged males and both long- and short-winged females (all North American species have females with long wings).
• Forewings have reduced veins:
• Full-length forewings are hairy.
• Shortened forewings are 1/3 length of abdomen, hairy and “leathery.”
• Forewing vein M is not branched.
• Cubital loop has distinct Y-shape, and doesn't hit wing margin before loop.
• Pterostigma is shallow.
• Areola postica has flat shape, not curved.
• Hindwing surface and margin are covered with hairs, but veins are hairless.
• Male:
  
• Phallosome is simple.
• Parameres are reduced and membranous (sometimes absent).
• Female:
  
• Subgenital plate is rounded or flattened distally.
• Some species are viviparous with gonapophyses absent or very reduced.
• In oviparous species gonapophyses are reduced:
• Ventral valve is absent.
• Dorsal valve is slender and pointed.
• External valve is broad and hairy.
• Eggs:  Eggs are covered with debris, but not covered with silk threads.

How to Know the Family

• Often found in colonies under dense webs on the surface of tree trunks.
• Body is hairy and red- or orange-brown.
• Most species have short-winged males and both long- and short-winged females (all North American species have females with long wings).
• Full-length forewings are hairy.
• Forewings have reduced veins:
• Shortened forewings are 1/3 length of abdomen, hairy and “leathery.”
• Forewing areola postica has flat shape, not curved.
• Forewing vein M is not branched.
• Cubital loop has distinct Y-shape, and does not hit wing margin before loop.

Family Monophyly

Monophyly of Archipsocidae is strongly supported by several morphological synapomorphies (see Characteristics; Yoshizawa 2002) and by molecular data including three mitochondrial and one nuclear gene (18S nDNA; 12S, 16S, COI mtDNA, Johnson & Mockford 2003, Johnson et al. 2004).

Other Names for Archipsocidae

• Archipsocetae

References

Badonnel, A. 1966. Sur le genre Archipsocus Hagen (Psocoptera, Archipsocidae). Bulletin du Muséum National d'Histoire Naturelle, Paris 38:409-415.

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.