The Order Siphonaptera comprises cosmopolitan haematophagous ectoparasites of birds and mammals. More than ten years have past since the last list of species known for Argentina. Herein we provide a review of the fleas from the country, which includes an updated list, host species and geographical distribution for each taxa, as well as some comments. We report 127 species and subspecies belonging to eleven different families; 42 of these species are endemic. Four genera (Adoratopsylla, Cleopsylla, Ctenidiosomus, and Nonnapsylla) and six species and subspecies (Adoratopsylla (Adoratopsylla) antiquorum antiquorum, Agastopsylla pearsoni, Polygenis (Polygenis) roberti beebei, Plocopsylla (Plocopsylla) silewi, Plocopsylla (Plocopsylla) wilesi and Tunga terasma) are added to the list for Argentina. Nine species new to science are included, described on the bases of specimens collected from Argentina (Ctenidiosomus austrinus, Ectinorus (Ectinorus) lareschiae, Ectinorus (Ectinorus) spiculatus, Ectinorus (Ectinorus) morenoi, Hectopsylla narium, Plocopsylla (Plocopsylla) linardii, Neotyphloceras crackensis, Neotyphloceras pardinasii and Tunga perforans). Information provided herein contributes to the knowledge of the fleas from Argentina, necessary to a better understanding of their role as parasites themselves and vectors of zoonotic importance.

We studied patterns of species co‐occurrence in communities of ectoparasitic arthropods (ixodid ticks, mesostigmate mites and fleas) harboured by rodent hosts from South Africa (Rhabdomys pumilio), South America (Scapteromys aquaticus and Oxymycterus rufus) and west Siberia (Apodemus agrarius, Microtus gregalis, Microtus oeconomus and Myodes rutilus) using null models. We compared frequencies of co‐occurrences of parasite species or higher taxa across host individuals with those expected by chance. When non‐randomness of parasite co‐occurrences was detected, positive but not negative co‐occurrences of parasite species or higher taxa prevailed (except for a single sample of mesostigmate mites from O. rufus). Frequency of detection of non‐randomness of parasite co‐occurrences differed among parasite taxa, being higher in fleas and lower in mites and ticks. This frequency differed also among host species independent of parasite taxon, being highest in Microtus species and lowest in O. rufus and S. aquaticus. We concluded that the pattern of species co‐occurrence in ectoparasite communities on rodent hosts is predominantly positive, depends on life history of parasites and may be affected to a great extent by life history of a host.

The relative effects of host species identity, locality and season on ectoparasite assemblages (relative abundances and species richness) harboured by four cricetid rodent hosts (Akodon azarae, Oligoryzomys flavescens, Oxymycterus rufus and Scapteromys aquaticus) were assessed across six closely located sites in Buenos Aires province, Argentina. Relative abundances of ectoparasites (14 species including gamasid mites, an ixodid tick, a trombiculid mite, lice and fleas), as well as total ectoparasite abundance and species richness, were determined mainly by host species and to a lesser extent by locality (despite the small spatial scale of the study), whereas seasonal effect was weak, albeit significant. The abundances of some ectoparasites were determined solely by host, whereas those of other ectoparasites (sometimes belonging to the same higher taxon) were also affected by locality and/or season. In gamasids, there was a significant effect of locality for some species, but not for others. In fleas and lice, the effect of locality was similar in different species, suggesting that this effect is related to the characteristic life history strategy.

Infestation parameters and indices of mites, ticks and fleas associated with wild rodents from northeastern

The human flea Pulex irritans Linnaeus, 1758 (Siphonaptera: Pulicidae) is one of the most studied species together with the cat flea Ctenocephalides felis Bouché, 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 study of two different populations of P. irritans (Spain and Argentina). Accordingly, internal transcribed spacer (ITS)1 and ITS2 of rDNA and the partial cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cytb) mtDNA genes of these taxa were sequenced. Furthermore, the taxonomy, origin, evolution and phylogeny of P. irritans was assessed. The morphometric data obtained did not show significant differences between P. irritans specimens from Spain and Argentina, even when these two populations were collected from different hosts; however, there was a considerable degree of molecular divergence between both populations based on nuclear and mitochondrial markers. Thus, it is proposed that P. irritans, in contrast with other generalist fleas, maintains a certain degree of morphological similarity, at least between Western Palearctic and Neotropical areas. Furthermore, two well defined geographical genetic lineages within the P. irritans species are indicated, suggesting the existence of two cryptic species that could be discriminated by a polymerase chain reaction-linked restriction fragment length polymorphism.