The new species Aquanirmus major Cicchino & González Acuña found on the Great Grebe, Podiceps major, from different localities of Argentina and Chile, is described and illustrated, giving comments on its affinities and differences with the remaining three species included in the Aquanirmus emersoni-species complex.
Chewing lice; bird lice; Ischnocera; South America; ectoparasite
