Ischnocera

Ischnocera is a large parvorder of lice from the infraorder Phthiraptera. The parvorder consists of chewing lice, which feed on the feathers and skin debris of birds. Many species of Ischnocera have evolved an elongated body shape, which allows them to conceal themselves within plumage to avoid being dislodged during preening or flight. Species in Ischnocera spend their entire lives living on a host and attach themselves to hippoboscid flies to help move across individual birds. Ischnocera contain the large family Philopteridae, along with a few other minor families. Ischnocera are distributed globally, with around 3,800 species identified. These lice are very host-specific, and each species rarely parasitizes outside of its preferred bird species. Birds infested by ischnoceran species can experience discomfort and damage to reproductive systems.

==Classification== Ischnocera previously included the mammalian parasitic lice Trichodectera, but phylogenetic studies had found the grouping to be paraphyletic, specifically in regard to the two major families Philopteridae and Trichodectidae. To resolve this, de Moya et al. proposed retaining the majority of the species (including Philopteridae) within Ischnocera, and then moving Trichodectidae to their own grouping called Trichodectera.