A New Species of Sucking Louse from the Long-tailed Ground Squirrel, Urocitellus undulatus , from Mongolia, with a Key to Species, and a Review of Host Associations and Geographical Distributions of Members of the Genus Linognathoides (Psocodea: Anoplura: Polyplacidae).

Members of the genus are ectoparasites of ground squirrels and marmots (Rodentia: Sciuridae) in the Nearctic, Palearctic, and Afrotropical regions. n. sp. is described based on adult male and female and third-instar nymphal specimens collected from the long-tailed ground squirrel () in Mongolia. The new species is compared morphologically to other members of the genus . Additionally, DNA sequences of a 610-base pair (bp) fragment of the nuclear gene, a 452-bp fragment of the mitochondrial gene, and a 363-bp fragment of the mitochondrial gene are provided. Host associations and geographical distributions of the 11 previously recognized species of the genus, and of n. sp., are reviewed. A dichotomous identification key to adults of all known species in the genus is provided.