Lepidopsocidae

Introduction

The family Lepidopsocidae contains 19 genera and about 200 species distributed worldwide.  Fifteen species are present in North America, mostly in tropical or subtropical regions. 

Lepidopsocids are small-to-medium sized bark lice that are easily recognized by their distinctive pointed wings, triangular head shape, and scaly or hairy body covering. Lepidopsocids can resemble tiny moths.  They live on trees, shrubs, and stone outcrops and are occasionally found in stored food products.

Characteristics

Synapomorphy

• Body and forewings are covered with scales or dense hairs. (Note: scales often fall off specimens that are preserved in liquid.)  

General Charaters

• Head:
  
• Head has triangular shape with eyes at the top outer margin.
• Antennae have up to 50 segments.
• Ocelli are far apart.
• Legs: Tarsi have 3 segments.
• Wings: 
  
• Adults may have full-length or reduced wings.
• Wings are usually pointed and often narrow.
• Forewings are covered with dense scales or (less commonly) dense hairs.  (Note: scales often fall off specimens that are preserved in liquid.)  
• Forewings:
• Veins are nearly parallel to long axis of wing.
• Pterostigma is not thickened.
• Veins CuP and 1A meet wing margin separately (do not form nodulus).
• Hindwing vein M usually has 2 branches.
• Male:
  
• Paraproct has an anal spine.
• Phallosome is composed of two arms that are never fused anteriorly.
• Female:
  
• Paraproct has an anal spine.
• Gonapophyses are reduced:
• Dorsal & ventral valves are usually absent.
• External valve is elongate and hairy.

How to Know the Family

• Head has triangular shape with eyes at the top outer margin.
• Wings are usually pointed and often narrow.
• Forewings are covered with dense scales or (less commonly) dense hairs.  
• Forewing veins are nearly parallel to long axis of wing.

Discussion of Phylogenetic Relationships

The monophyly of family Lepidopsocidae is supported by the presence of scales or dense hairs covering the body and forewings. Molecular analysis including the five genera of Lepidopsocidae strongly supports monophyly of the family (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.