Description of two new species of Ectinorus (Ectinorus) (Siphonaptera, Rhopalopsyllidae) from Argentina, including a morphometric approach.

Two new species of fleas of genus Ectinorus (Siphonaptera: Rhopalopsyllidae) are described from sigmodontine rodents (Rodentia: Cricetidae) collected during a survey of small mammals in northwestern Argentina.The new species belong to the subgenus Ectinorus and can be distinguished from all other species of the subgenus by the characteristics of the modified abdominal segments and by the genitalia. Moreover, the male of Ectinorus (Ectinorus) disjugis is described for the first time and the finding of this flea parasitizing the rodent Akodon spegazzinii, constitutes a new flea-host association. A phylogenetic analysis of the genus Ectinorus, using traditional morphological characters and morphogeometric data, is presented to support the erection of the new species of Ectinorus. An identification key for all species of Ectinorus is also provided. Our study increases to 38 the total number of species of the subgenus Ectinorus, and to 20 the number for Argentina. Phylogenetic analyses reveal that Ectinorus is monophyletic but the subgenera are not. This study offers a new interpretation of morphological diversity within the genus as well as an evaluation of hypotheses about their relationships.