The South American genus Cnemalobus (Coleoptera: Carabidae: Cnemalobini): phylogeny and biogeographic analysis with the description of four new species from extra-Andean Patagonian mountains.

The carabid beetle Cnemalobus Guérin-Ménéville, 1838 inhabits high- and lowland grasslands of southern South America. The highest diversity is found in the Patagonian Steppe, where distribution patterns are associated with latitude and elevation. Northern Patagonia, a large volcanic region with a complex geoclimatic history, exhibits elevated grades of endemism. However, a great deal remains unknown regarding diversification and biogeographical patterns for most of the endemic groups. We describe new Cnemalobus species restricted to isolated volcanoes from these extra-Andean mountain systems. We assess the phylogenetic relationships by updating the phylogeny of the genus and conduct a Bayesian binary Markov chain-Monte Carlo (MCMC) analysis on the resulting phylogenetic tree to discuss the biogeographical distribution patterns. We also provide a taxonomic key to all currently known species of Cnemalobus from the Patagonian Steppe. Our phylogenetic analysis supports the monophyly of the new species Cnemalobus tromen sp. nov., Cnemalobus silviae sp. nov., Cnemalobus aucamahuida sp. nov. and Cnemalobus domuyo sp. nov. grouped with C. diamante and C. nevado , referred to as the 'Extra-Andean' mountain lineage. Biogeographical analysis recognises vicariant events as the most plausible explanation for the allopatric distributions of the new species. We hypothesise that these vicariant events could be related to climatic barriers that likely promoted speciation processes by generating geographical isolation in ancestral populations. Our findings contribute significantly to the biogeographical understanding of the Patagonian volcanic region, prompting new inquiries to unravel the speciation processes of the endemic biota in extra-Andean mountain systems. ZooBank: urn:lsid:zoobank.org:pub:6A7585E8-5006-45BC-A1A3-F874F18A6049.

A possible case of offspring sex manipulation as result of a biased adult sex ratio.

Although random meiosis should prevent the facultative adjustment of offspring sex ratio, theory predicts that females should produce more of the sex with the higher reproductive value. We reported a case of offspring sex ratio manipulation in grass wrens Cistothorus platensis. Males in better body condition would have higher reproductive value than females due to the potential for social polygyny and extra-pair fertilizations. On the other hand, local demography influences reproductive strategies in grass wrens as male abundance affects both social polygyny and extra-pair paternity frequencies. We evaluated whether females bias their brood sex ratio in response to adult sex ratio and nestling body condition (a proxy for female's prospects of producing high-quality males). Females raised more male offspring when males were less abundant in the population (female-biased adult sex ratio). However, we found no relationship between nestling body condition and brood sex ratio, suggesting that females did not bias the brood sex ratio towards males when able to raise nestlings in better body condition. Taken together, our results provide the first suggestive evidence that female birds can manipulate their offspring sex ratio in response to the adult sex ratio.

Seroprevalence of leptospiral antibodies in rodents from riverside communities of Santa Fe, Argentina.

BACKGROUND: Leptospirosis is a zoonotic disease that can be transmitted by contact with the urine of infected mammals. Rodents play a mayor role in the transmission of leptospires to humans. The province of Santa Fe reports the greatest number of cases in Argentina. Yet, in this region, there are still knowledge gaps regarding the diversity of rodent species that may be hosts of pathogenic leptospires. The aims of this study were to evaluate the presence of leptospiral antibodies in rodents from three riverside communities of Santa Fe, and to identify factors associated with leptospiral infection. METHODOLOGY/PRINCIPAL FINDINGS: Each community was divided into three environmental settings based on the level of human disturbance, and sampled during two springs (Sep-Oct 2014 and 2015) and one autumn (Mar-Apr 2015). Serum samples of captured sigmodontine and murine rodents were tested for leptospiral antibodies by enzyme-linked immunosorbent assay (ELISA), and microagglutination test (MAT) was used to assess the infecting serovar in seropositive individuals. Factors influencing seropositivity were analyzed using logistic regression models. We caught 119 rodents, of which 101 serums were suitable for analysis. Most frequently trapped species were Scapteromys aquaticus, Akodon azarae and Oligoryzomys spp., with seroprevalences of 41.3%, 42.9% and 55% respectively. Seropositivity was higher in individuals with an average body condition score and in those that were sexually mature, but in the latter the differences were marginally significant. CONCLUSIONS/SIGNIFICANCE: Our results suggest that native rodents may be playing a role in the environmental circulation of pathogenic leptospires and provide relevant information for public health policies in the area.

Molecular characterization and phylogenetic assessment of agricultural-related noctuids (Lepidoptera: Noctuidae) of South America

ABSTRACT Accurate identification of species is fundamental to every biological research. While morphological identification is a time-consuming and skilled technique, straightforward molecular techniques require the availability of a database of previously sequenced and identified specimens. For most countries of South America, species of noctuids with available sequences are scarce, mostly restricted to species of economic importance, making molecular identification untenable. Here we sequenced the mitochondrial DNA 'barcode' region of the cytochrome c oxidase subunit I gene of 34 specimens pertaining to 26 species of South American noctuids, 20 of these for the first time. For all species, genetic distances were higher for interspecific than for intraspecific relations, supporting the utility of DNA 'barcodes' to identify species. Larger intraspecific divergences occurred in species of Agrotis and Anicla, and interspecific divergences lower than 2% occurred in about one fifth of the species, all in species of Agrotis, Feltia, and Anicla. These results will allow identifying these species using DNA 'barcodes', either for pest management or general biological studies. Furthermore, we carried out phylogenetic analyses with those sequences and 158 other sequences of 85 species of noctuids mined from GenBank. These analyses, in every case, grouped species of the same genus suggesting that the DNA 'barcodes' region alone can be useful for lower level phylogeny in this group, recovering as monophyletic groups such as Copitarsia, Agrotis and Austrandesiita. Conversely, groups such as Mythimna (Mythimna) and the subgenera of Feltia were not recovered as monophyletic, suggesting the need for further taxonomic studies in these groups.