Origin, evolution, phylogeny and taxonomy of Pulex irritans

Abstract

The human fleaPulex irritansLinnaeus, 1758 (Siphonaptera: Pulicidae) isone of the most studied species together with the cat fleaCtenocephalides felisBouché,1835, because they have a cosmopolitan distribution and are closely related to humans.The present study aimed to carry out a comparative morphometric and molecular studyof two different populations ofP. irritans(Spain and Argentina). Accordingly, internaltranscribed spacer (ITS)1 and ITS2 of rDNA and the partial cytochromecoxidasesubunit 1 (cox1) and cytochromeb(cytb) mtDNA genes of these taxa were sequenced.Furthermore, the taxonomy, origin, evolution and phylogeny ofP. irritanswas assessed.The morphometric data obtained did not show significant differences betweenP.irritansspecimens from Spain and Argentina, even when these two populations werecollected from different hosts; however, there was a considerable degree of moleculardivergence between both populations based on nuclear and mitochondrial markers.Thus, it is proposed thatP. irritans, in contrast with other generalist fleas, maintainsa certain degree of morphological similarity, at least between Western Palearctic andNeotropical areas. Furthermore, two well defined geographical genetic lineages withintheP. irritansspecies are indicated, suggesting the existence of two cryptic species thatcould be discriminated by a polymerase chain reaction-linked restriction fragment lengthpolymorphism.