Species distribution of genus Quadraceps (Mallophaga: Philopteridae) on New Zealand Endemic plovers

The louse genus Quadraceps Clay & Meinertzhagen is represented on New Zealand endemic Charadriinae by Q. dominella Timmermann, Q. novaeseelandiae Timmermann, and Q. cedemajori Timmermann, which are parasitic on Charadrius obscurus (Gmelin), Thinornis novaeseelandiae (Gmelin), and Anarhynchus frontalis Quoy and Gaimard respectively. Charadrius bicinctus Jardine and Selby is parasitised by both Q. novaeseelandiae and Q. cedemajor. This pattern of distribution is unusual, in that two Quadraceps species are sympatric on the same host individuals, and host species that are not closely related have louse species in common. It seems probable that C. bicinctus has been secondarily colanized by two spcies of Quadraceps. One species appears to of primarily evolved on T. novaeseelandiae and the other on A. frontalis.