Psocodea

Psocodea is a taxonomic group of insects comprising the bark lice, book lice and parasitic lice. It was formerly considered a superorder, but is now generally considered by entomologists as an order. Despite the greatly differing appearance of parasitic lice (Phthiraptera), they are believed to have evolved from within the former order Psocoptera, which contained the bark lice and book lice, now found to be paraphyletic.

Psocomorpha is a suborder of barklice in the order Psocodea (formerly Psocoptera). There are more than 20 families and 5,300 described species in Psocomorpha. thumb|Xanthocaecilius sommermanae

Trogiomorpha is one of the three major suborders of barklice, booklice, and parasitic lice in the order Psocodea (formerly Psocoptera), alongside Troctomorpha and Psocomorpha. There are about eight families and more than 430 described species in Trogiomorpha. Trogiomorpha is widely agreed to be the earliest diverging of the three suborders, and retains the most primitive characteristics. thumb|Trogium pulsatorium

Troctomorpha is one of the three major suborders of Psocodea (formerly Psocoptera)(barklice, booklice, and parasitic lice), alongside Psocomorpha and Trogiomorpha. There are more than 30 families and 5,800 described species in Troctomorpha. The order includes parasitic lice, which are most closely related to the booklice family Liposcelididae.