Check list of ground-dwelling ant diversity (Hymenoptera: Formicidae) of the Iguazú National Park with a comparison at regional scale

We describe the ant fauna of Iguazú National Park (INP), a region of high biodiversity andendemism in northeastern Argentina that includes the southernmost protected area ofthe Atlantic Forest (AF). Ants were sampled over seven periods from 1998 to 2011 usinga variety of techniques. We also surveyed museum collections and the scientific literatureto obtain additional records of ants from INP. In addition to providing a species list, wecompare ant composition of INP to other sites in the Upper Paraná, Serra do Mar CoastalForest and Araucaria ecoregion of AF. A total of 172 ant species belonging to 56 genera arereported; 56 species are new records for Misiones Province and 39 species are reportedfrom Argentina for the first time. Alto Paraná and Canindeyú departments in Paraguaypresent the most similar ant fauna to INP. Serra da Bodoquena in Brazil and Pilcomayoin Argentina showed higher similarity with the Upper Paraná AF ecoregion, despite thatSerra da Bodoquena is composed of a mix of ecoregions. Ant diversity was lower in UpperParaná than in Serra do Mar Coastal Forest ecoregion. This difference may result fromhigher primary productivity and a greater altitudinal variation in the coastal region.Fil: Hanisch, Priscila Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Calcaterra, Luis Alberto. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leponce, M.. Royal Belgian Institute of Natural Sciences. Aquatic and Terrestrial Ecology unit; BélgicaFil: Achury, R.. University of Illinois at Urbana; Estados UnidosFil: Suarez, A. V.. University of Illinois at Urbana; Estados UnidosFil: Silva, R. R.. Museu Paraense Emílio Goeldi; BrasilFil: Paris, Carolina Ivon. Universidad de Buenos Aires; Argentin

Wasmannia Forel (Hymenoptera: Formicidae: Myrmicinae) in Argentina: systematics and distribution

The ant genus Wasmannia is endemic to the Neotropics, with 10 species occurring within the presumptive native range for the genus from Mexico to Argentina. Only the little fire ant, Wasmannia auropunctata is widely distributed being present from central-eastern Argentina to Bermuda, and has become infamous due to its recent worldwide expansion and status as an invasive pest. The objective of this work was to study the systematics and distribution of Wasmannia in its southern limit of distribution in Argentina. Out of the three species reported so far for Argentina, only W. auropunctata was found to be widely distributed, but abundant only in disturbed habitats mostly in the Northeast. Herein, the distribution of Wasmannia auropunctata is extended and its queen and male castes are redescribed, along with descriptions of gynandromorphs (specimens with left side of the head similar to a male and right side similar to a queen). Wasmannia sulcaticeps and W. williamsoni are much less common and widespread. W. sulcaticepsis mostly found in mountain forests in northwestern Argentina, whereas W. williamsoni is only found in shrublands and grasslands in central eastern Argentina, and most frequently in mountain grasslands. Both species overlap with W. auropunctata, which is more common in the lowlands, between approximately 400 and 1000 m elevation. The queen of W. williamsoni is described and queen and male of W. sulcaticeps are redescribed. A new species, Wasmannia longiseta n. sp. Cuezzo and Calcaterra, recently found in northeastern Argentina is described based on worker morphology. Wasmannia rochai is recorded for the first time in Misiones, extending its distribution range from São Paulo (Brazil) to Misiones in northeastern Argentina. A key to the worker caste is provided. A cladistic analysis based on discrete and continuous morphological characters is presented as a first attempt to clarify the phylogenetic relationships between the known species of Wasmannia.Fil: Cuezzo, Fabiana del Carmen. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales E Instituto Miguel Lillo. Instituto Superior de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Calcaterra, Luis Alberto. Fundación Para El Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chifflet, Lucila. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Follet, P. A.. Pacific Basin Agricultural Research Center; Estados Unido

Prospecting for viral natural enemies of the fire ant Solenopsis invicta in Argentina.

Metagenomics and next generation sequencing were employed to discover new virus natural enemies of the fire ant, Solenopsis invicta Buren in its native range (i.e., Formosa, Argentina) with the ultimate goal of testing and releasing new viral pathogens into U.S. S. invicta populations to provide natural, sustainable control of this ant. RNA was purified from worker ants from 182 S. invicta colonies, which was pooled into 4 groups according to location. A library was created from each group and sequenced using Illumina Miseq technology. After a series of winnowing methods to remove S. invicta genes, known S. invicta virus genes, and all other non-virus gene sequences, 61,944 unique singletons were identified with virus identity. These were assembled de novo yielding 171 contiguous sequences with significant identity to non-plant virus genes. Fifteen contiguous sequences exhibited very high expression rates and were detected in all four gene libraries. One contig (Contig_29) exhibited the highest expression level overall and across all four gene libraries. Random amplification of cDNA ends analyses expanded this contiguous sequence yielding a complete virus genome, which we have provisionally named Solenopsis invicta virus 5 (SINV-5). SINV-5 is a positive-sense, single-stranded RNA virus with genome characteristics consistent with insect-infecting viruses from the family Dicistroviridae. Moreover, the replicative genome strand of SINV-5 was detected in worker ants indicating that S. invicta serves as host for the virus. Many additional sequences were identified that are likely of viral origin. These sequences await further investigation to determine their origins and relationship with S. invicta. This study expands knowledge of the RNA virome diversity found within S. invicta populations

Geographic Spread of Pheidole obscurithorax (Hymenoptera: Formicidae)

The South American big-headed ant Pheidole obscurithorax was first found in North America in Mobile, Alabama in 1949. Since then, this species has also been recorded in Florida, Georgia, Mississippi, and Texas. We compiled and mapped published and unpublished specimen records of P. obscurithorax from >170 sites in South America and the US to evaluate the current geographic range of this species and its possible future spread. We documented the earliest known records for nine geographic areas (South American countries and US states). Site records of P. obscurithorax ranged 27.5 degrees of latitude (from 6.7°S to 34.2°S) in South America, and 3.5 degrees of latitude (from 28.0°N to 31.5°N) in North America. It may be that the North American populations of P. obscurithorax have a fairly narrow range of climatic tolerances. Earlier genetic analyses of native and exotic populations of P. obscurithorax found that the North America populations appear to originate from a single introduction from a population most closely related to native study populations from a stretch along the Paraná River in Argentina from Resistencia (27.5°S) to Santa Fe (31.6°S). This latitudinal range matches the current latitudinal range of P. obscurithorax in North America. Alternatively, the much greater latitudinal range of P. obscurithorax in South America suggests that exotic populations of P. obscurithorax may have potential for much additional expansion in North America and beyond. In South America, P. obscurithorax has a similar native range as the invasive fire ant Solenopsis invicta. In the North America, exotic populations of P. obscurithorax may spread like S. invicta has, across the southeast of the US and into the West Indies.Fil: Wetterer, James K.. Mississippi State University; Estados UnidosFil: MacGown, Joe A.. Mississippi State University; Estados UnidosFil: Calcaterra, Luis Alberto. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Ecological dominance of the red imported fire ant, Solenopsis invicta, in its native range

© 2008 Springer. Part of Springer Science+Business MediaDespite the widespread impacts invasive species can have in introduced populations, little is known about competitive mechanisms and dominance hierarchies between invaders and similar taxa in their native range. This study examines interactions between the red imported fire ant, Solenopsis invicta, and other above-ground foraging ants in two habitats in northeastern Argentina. A combination of pitfall traps and baits was used to characterize the ant communities, their dominance relationships, and to evaluate the effect of phorid flies on the interactions. Twenty-eight ant species coexisted with S. invicta in a gallery forest gap, whereas only ten coexisted with S. invicta in a xerophytic forest grassland. S. invicta was the most numerically dominant species in the richest and complex habitat (gallery forest); however it performed better as discoverer and dominator in the simpler habitat. S. invicta was active during day and night. In spite of its poor capacity to discover resources, S. invicta showed the highest ecological dominance and the second-best behavioral dominance after Camponotus blandus. S. invicta won 78% of the interactions with other ants, mostly against its most frequent competitor, Pheidole cf. obscurithorax, dominating baits via mass recruitment and chemical aggression. P. cf. obscurithorax was the best food discoverer. S. invicta won 80% of the scarce interactions with Linepithema humile. Crematogaster quadriformis was one of the fastest foragers and the only ant that won an equal number of contests against S. invicta. The low presence of phorid flies affected the foraging rate of S. invicta, but not the outcome of interspecific interactions. This study revealed that the red imported fire ant ecologically dominated other terrestrial ants in its native range; however, other species were able to be numerically dominant or co-dominant in its presenceLuis A. Calcaterra, Juan. P. Livore, Alicia Delgado and Juan A. Brian

Geographic variation of singleton expression levels of sequences for each RNA library (see Fig 1 for map of collection locations and RNA library groupings).

<p>Sequences were binned according to broader taxonomic categories (Top) and known or newly described <i>Solenopsis invicta</i> viruses (Bottom). Note that expression levels are shown in log scales.</p

Contiguous sequences (Contigs) with significant viral identity by BLASTX analysis of the GenBank database and considered high likelihood viral prospects from RNA libraries created from <i>Solenopsis invicta</i> worker ants.

<p>Contigs were first sorted in descending order based on the number of the sequences comprising it, followed by the libraries represented.</p

gs composed of sequences from all four gene libraries evaluated by RT-PCR and PCR.

<p>Conti Reverse transcription was required for successful amplification of all contigs. RT-PCR was also conducted with RNA obtained from <i>S</i>. <i>invicta</i> colonies (<i>n</i> = 27) collected in the U.S. to determine if the contig was present in the introduced range.</p

Summary of collection information for <i>Solenopsis invicta</i> colonies used in RNA library preparation.

<p>Library designation represents South American Library (SAL).</p