A critically co-endangered feather louse n. sp. (Phthiraptera: Philopteridae) detected through conservation intervention for the western ground parrot (Psittaculidae).

Martin, Keatley & Ash n. sp. from the western ground parrot North, 1911 (Psittaculidae) is proposed based on combined evidence from morphology and mitochondrial DNA. Phylogenetically, the new species is closest to its two known congeners from Western Australia: . Price, Johnson & Palma, 2008 from Bourke's parrot (Gould, 1841) and the scarlet-chested parrot (Gould, 1841), and . Guimarães, 1985 from the Australian ringneck parrot (Shaw, 1805). Morphologically it is distinguishable by abdominal chaetotaxy and characters of the male genitalia, and is most similar to . and . Guimarães, 1985; the latter has no representative sequence data. is the eleventh species of its genus and the only metazoan parasite known from . , which is among Australia's most endangered vertebrates. The new louse is apparently restricted to . and is therefore co-endangered, facing at least the same likelihood of extinction as its host. We recommend ongoing translocation and field monitoring efforts for . include monitoring but not treatment for lice infestations in otherwise healthy individuals, and that the care management plan for captive . considers that . is similarly imperilled.