Atropetae

Introduction

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.

Characteristics

Synapomorphies

• In the female:
  
• The ovipositor is composed of the elongated external valves of the gonapophyses joined together at midline by a membrane.
• The presence of glandular accessory bodies in the spermathecal sac.

General Characters

• Head:
  
• Head is short and broad.
• Antennae have more than 18 segments without ringed sculpturing (annulations).
• Legs:
• Tarsi have 3 segments
• Wings:
• Adults can have full-length or short wings or can be wingless. 
• Wings are covered with hairs or scales.
• Forewing veins CuP and A1 reach the wing margin separately, so nodulus is absent.
• Hindwing vein A does not branch.  
• Female:  
• Paraproct has an anal spine.
• Ovipositor is composed of the fused, elongate external valves of the gonapophyses.
  
• Spermathecal sac has one or two glandular accessory bodies.
• Male:  
• Paraproct has an anal spine.
• Phallosome is composed of two arms that are never fused anteriorly.

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).

References

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.