Genetically Depauperate and Still Successful: Few Multilocus Genotypes of the Introduced Parthenogenetic Weevil (Coleoptera: Curculionidae) Prevail in the Continental United States.

is a parthenogenetic weevil native to South America that is currently distributed worldwide. This flightless species is polyphagous and capable of modifying gene expression regimes for responding to stressful situations. was first reported in the continental United States in 1879 and has rapidly colonized most of the world since.

City puzzles: Does urban land scape affect genetic population structure in Aedes aegypti?

Cities usually offer a suitable environment for the dengue vector Aedes aegypti, providing oviposition sites, accessibility to human hosts and nectar meals. However, large urban centres are highly heterogeneous environments, forming a patched landscape that could affect Ae. aegypti population dynamics and dispersal.

Stable inversion clines in a grasshopper species group despite complex geographical history.

Chromosomal inversions are known to play roles in adaptation and differentiation in many species. They involve clusters of correlated genes (i.e.

Host-specific gene expression as a tool for introduction success in Naupactus parthenogenetic weevils.

Food resource access can mediate establishment success in invasive species, and generalist herbivorous insects are thought to rely on mechanisms of transcriptional plasticity to respond to dietary variation. While asexually reproducing invasives typically have low genetic variation, the twofold reproductive capacity of asexual organisms is a marked advantage for colonization. We studied host-related transcriptional acclimation in parthenogenetic, invasive, and polyphagous weevils: Naupactus cervinus and N.

Genome-Wide Screening of Aedes aegypti (Culicidae: Diptera) Populations From Northwestern Argentina: Active and Passive Dispersal Shape Genetic Structure.

Aedes aegypti is the primary vector of arboviruses of great impact on human health. Our goal was to assess the spatial genetic structure of Ae. aegypti at the regional and local levels in Northwestern Argentina, an area with high prevalence of dengue fever.

A Species delimitation approach to uncover cryptic species in the South American fire ant decapitating flies (Diptera: Phoridae: Pseudacteon).

South American fire ant decapitating flies in the genus Pseudacteon (Diptera: Phoridae) are potential biocontrol agents of the invasive fire ants Solenopsis invicta and S. richteri in the United States and other regions of the world due to their high host specificity and the direct and indirect damage to their host ants. Despite their importance and the fact that several flies have already been released in the US, little is known about the genetic variability and phylogenetic relationships of Pseudacteon flies parasitizing South American fire ants in the Solenopsis saevissima species-group.

Game of clones: Is Wolbachia inducing speciation in a weevil with a mixed reproductive mode?

Parthenogenesis is widely distributed in Metazoa but it is especially frequent in weevils (Coleoptera, Curculionidae) with one fifth of all known cases. Previous studies have shown that in the tribe Naupactini parthenogenetic reproduction most likely originated with an infection of the endoparasitic bacterium Wolbachia pipientis. In particular, Pantomorus postfasciatus possess a mixed reproductive mode: some populations have males while in others they are absent, and females produce clones by thelytoky.

Southern expansion of the invasive ant Wasmannia auropunctata within its native range and its relation with clonality and human activity.

The little fire ant Wasmannia auropunctata, native to the Neotropics, has become a serious pest worldwide over the past 100 years. It was originally distributed from Mexico to northern Argentina and new evidence suggests a recent southern range expansion during the last 60 years reaching central Argentina. This supercolonial ant species has a polymorphic reproductive system.

A tale of swinger insects: Signatures of past sexuality between divergent lineages of a parthenogenetic weevil revealed by ribosomal intraindividual variation.

Naupactus cervinus (Boheman) (Curculionidae, Naupactini) is a parthenogenetic weevil native to the Paranaense Forest which displays high levels of genetic variation. Two divergent clades were identified, one ranging in forest areas (Forest clade), and the other in open vegetation areas (Grassland clade). Both of them have individuals with high levels of heterozygosity in ribosomal sequences.

Sulfated Polysaccharides in the Freshwater Green Macroalga Not Linked to Salinity Adaptation.

The presence of sulfated polysaccharides in of seaweeds is considered to be a consequence of the physiological adaptation to the high salinity of the marine environment. Recently, it was found that sulfated polysaccharides were present in certain freshwater species and some vascular plants. (Ulvophyceae, Chlorophyta) is one of the largest genera of green algae that are able to grow in both, seas and freshwater courses.

Unraveling the diversification history of grasshoppers belonging to the " (Oedipodinae: Acrididae) species group: a hotspot of biodiversity in the Central Andes.

The Andean Mountain range has been recognized as one of the biodiversity hotspots of the world. The proposed mechanisms for such species diversification, among others, are due to the elevation processes occurring during the Miocene and the intensive glacial action during the Pleistocene. In this study we investigated the diversification history of the grasshopper species complex which shows a particularly wide latitudinal and altitudinal distribution range across the northern, central and southern Andes in South America.

Out of the forest: past and present range expansion of a parthenogenetic weevil pest, or how to colonize the world successfully.

Previous research revealed complex diversification patterns in the parthenogenetic weevil Naupactus cervinus. To understand the origin of clonal diversity and successful spreading of this weevil, we investigated its geographic origin and possible dispersal routes and whether parthenogens can persist in habitats under unsuitable environmental conditions. This study is based on samples taken throughout a broad area of the species' range.

Evolutionary history of the little fire ant Wasmannia auropunctata before global invasion: inferring dispersal patterns, niche requirements and past and present distribution within its native range.

The evolutionary history of invasive species within their native range may involve key processes that allow them to colonize new habitats. Therefore, phylogeographic studies of invasive species within their native ranges are useful to understand invasion biology in an evolutionary context. Here we integrated classical and Bayesian phylogeographic methods using mitochondrial and nuclear DNA markers with a palaeodistribution modelling approach, to infer the phylogeographic history of the invasive ant Wasmannia auropunctata across its native distribution in South America.

Potential geographic distributions and successful invasions of parthenogenetic broad-nosed weevils (Coleoptera: Curculionidae) native to South America.

Ten species of parthenogenetic broad-nosed weevils (Coleoptera: Curculionidae: Entiminae) native to Argentina, southern Brazil, and Uruguay were selected for niche modeling analysis based on climatic data and altitude, to evaluate their potential range expansion inside and outside South America. The selected species belong to five genera of the tribe Naupactini affecting economically important crops. Until present, five of the 10 species analyzed here have invaded prairies and steppes of countries outside South America (Australia, New Zealand, Mexico, United States, and South Africa): Aramigus tessellatus (Say), Atrichonotus sordidus (Hustache), Atrichonotus taeniatulus (Berg), Naupactus leucoloma Boheman, and Naupactus peregrinus (Buchanan).

Speciation in the asexual realm: is the parthenogenetic weevil Naupactus cervinus a complex of species in statu nascendi?

Population genetic theory shows that asexual organisms may evolve into species, which behave as independent evolutionary units. As a result, they form genotypic clusters separated by deep gaps due to geographic isolation and/or divergent selection. Identification of several genetically divergent groups of weevils embodied in the nominal species Naupactus cervinus deserves further study, in order to test if these lineages are evolving independently.

Trichinella patagoniensis n. sp. (Nematoda), a new encapsulated species infecting carnivorous mammals in South America.

Until a few years ago, Trichinella spiralis was the only taxon of the genus Trichinella detected in both domestic and wild animals of South America. Recently, a new genotype, named Trichinella T12, was identified in cougars (Puma concolor) from Argentina, on the basis of molecular studies using mitochondrial and nuclear ribosomal markers. In the present study, cross-breeding experiments indicated that Trichinella T12 is reproductively isolated from all other encapsulated Trichinella spp.

Mito-nuclear genetic comparison in a Wolbachia infected weevil: insights on reproductive mode, infection age and evolutionary forces shaping genetic variation.

Background: Maternally inherited endosymbionts like Wolbachia pipientis are in linkage disequilibrium with the mtDNA of their hosts. Therefore, they can induce selective sweeps, decreasing genetic diversity over many generations. This sex ratio distorter, that is involved in the origin of parthenogenesis and other reproductive alterations, infects the parthenogenetic weevil Naupactus cervinus, a serious pest of ornamental and fruit plants.

Wolbachia infection in the tribe Naupactini (Coleoptera, Curculionidae): association between thelytokous parthenogenesis and infection status.

Several parthenogenetic species of broad-nosed weevils exist, some of them of economic importance because of their pest status. Screening of the maternally inherited Wolbachia bacterium in 29 weevils of the tribe Naupactini, using multilocus sequence typing allowed us to assess a significant correlation between asexuality and infection, and suggests an involvement of Wolbachia in the origin of this reproductive mode. The nine Wolbachia strains retrieved from the Naupactini belong to the B supergroup.

Phylogeography of the armadillo Chaetophractus villosus (Dasypodidae Xenarthra): post-glacial range expansion from Pampas to Patagonia (Argentina).

We report a phylogeographic study of Chaetophractus villosus populations in Argentina. Control Region (CR) sequences (484 bp) were obtained for 76 C. villosus from 20 locations across the species whole distribution range.

Microsatellite variation in maize landraces from Northwestern Argentina: genetic diversity, population structure and racial affiliations.

The highland region or Northwestern Argentina (NWA) is one of the southernmost areas of native maize cultivation and constitutes an expansion of the peruvian Andes sphere of influence. To examine the genetic diversity and racial affiliations of the landraces cultivated in this area, 18 microsatellite markers were used to characterize 147 individuals from 6 maize races representative of traditional materials. For the whole data set, a total of 184 alleles were found, with an average of 10.

Molecular evidence for a novel encapsulated genotype of Trichinella from Patagonia, Argentina.

At present, Trichinella spiralis is the only species of this genus reported from South America. Herein, we detail a molecular analysis of a new encapsulated isolate of muscle larvae of Trichinella, found in a mountain lion (Puma concolor) coming from the Patagonia, Argentina. We studied three DNA regions previously probed to be useful for the identification of all eleven recognized Trichinella genotypes: expansion segment 5 (ES5), cytochrome c-oxidase subunit I (COI) and 5S ribosomal DNA intergenic spacer region (5S ISR).

B chromosome polymorphism in maize landraces: adaptive vs. demographic hypothesis of clinal variation.

Cytogenetic analysis of maize landraces from northwestern Argentina has revealed an altitudinal cline in the mean number of B chromosomes (B's) per plant, with cultivars growing at higher altitudes exhibiting a higher number of B's. Altitudinal and longitudinal clines are frequently interpreted as evidence of selection, however, they can also be produced by the interplay between drift and spatially restricted gene flow or by admixture between previously isolated populations that have come into secondary contact. Here, we test the adaptive significance of the observed altitudinal gradient by comparing the levels of differentiation in the mean number of B's to those obtained from 18 selectively neutral loci [simple sequence repeats (SSRs)] among seven populations of the cline.