Abrocomaphthirus hoplai, a new genus and species of sucking louse from Chile and its relevance to zoogeography

Both sexes of Abrocomaphthirus hoplai, new genus and new species (Anoplura: Polyplacidae), are described and illustrated. The endemic Chilean chinchil la rat Abrocoma bennetti Waterhouse (Rodentia: Abrocomidae) is the type hos t. The definition of the family Polyplacidae is amended to accommodate the new genus. Polyplax longa (Werneck), also referred to in the literature as Neohaematopinus longus Werneck, is reassigned to Abrocomaphthirus. The host of A. longus comb.n., is Abrocoma cinerea Thomas, another chinchilla rat, which inhabits parts of Argentina, Bolivia, Chile and Peru. The erection of Abrocomaphthirus as a distinct genus has important zoogeographical and evo lutionary implications. The tenuous anomaly of P. longa being the sole nati ve representative of the genus Polyplax in South America, possibly with Afr ican affinities, is now refuted. Instead, partial colonization of the neotr opics by native species of both Polyplax and Neohaematopinus appears to hav e been relatively recent and from North America. The phylogenetic affinitie s of Abrocomaphthirus are unknown, but it appears to be closely related to other, more ancient, native South American polyplacid louse genera, such as Cuyana, Eulinognathus, Galeophthirus, and Lagidiophthirus. Arguments are p resented in support of an ancestral zoogeographical link to Africa for thes e louse genera.