Lice

Classification

Lice are classified as an infraorder called Phthiraptera, named by Ernst Haeckel in 1896. Phthiraptera was previously recognized as an order, and was considered the sister taxon to the order Psocoptera, which contains booklice, barklice and barkflies, all within the greater group called Psocodea. However, a 2021 genetic study determined that Phthiraptera lice are a highly modified lineage within the Psocoptera group, thus rendering Psocoptera paraphyletic and necessating a classification change. Phthiraptera is now nested within the suborderTroctomorpha, belonging to the now-ranked order Psocodea. Within Psocodea, the Phthiraptera lice are most closely related to familyLiposcelididae.