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Composición de hormigas e interacciones competitivas con Wasmannia auropunctata en fragmentos de Bosque seco Tropical
ACHURY,RAFAEL; CHACóN DE ULLOA,PATRICIA; ARCILA,áNGELA MARíA;
Revista Colombiana de Entomología , 2008,
Abstract: disturbance increases the probability of dominance by the little fire ant wasmannia auropunctata (formicidae: myrmicinae), an indicator species of low diversity ant communities in tropical dry forest fragments of the cauca river valley (colombia). in order to study interactions of interspecific competition involving this species, we conducted experiments with soil-surface tuna-baits at four localities: alejandría, el medio, el vínculo and san julián. three biotopes were distinguished at each locality: forest interior, forest margin and their surrounding matrices (sugar cane or pasture). based on information obtained from the composition of ants at the baits, competition ability indices were calculated. attraction to the baits was 91%, for a total of 66 species in 30 genera. species composition was mainly influenced by locality conditions. the myrmicines pheidole, solenopsis and crematogaster had the greatest interaction with w. auropunctata and partitioning of the baits was mostly influenced by biotope. bait use by other species was determined by the abundance of w. auropunctata; if the bait had more than a mean of 500 workers, the resource was not shared. w. auropunctata emerged as the dominant species in the upper cauca river watershed and this was mainly accomplished by exploitation competition, allowing the ants to rapidly take advantage of resources by recruiting a large number of workers.
Distribution of Endosymbiotic Reproductive Manipulators Reflects Invasion Process and Not Reproductive System Polymorphism in the Little Fire Ant Wasmannia auropunctata  [PDF]
Olivier Rey, Arnaud Estoup, Benoit Facon, Anne Loiseau, Alexandre Aebi, Olivier Duron, Fabrice Vavre, Julien Foucaud
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0058467
Abstract: Endosymbiotic reproductive manipulators may have drastic effects on the ecological and evolutionary dynamics of their hosts. The prevalence of these endosymbionts reflects both their ability to manipulate their hosts and the history of the host populations. The little fire ant Wasmannia auropunctata displays a polymorphism in both its reproductive system (sexual versus clonal populations) and the invasive status of its populations (associated to a habitat shift). We first screened for the presence of a diverse array of reproductive parasites in sexual and clonal populations of W. auropunctata, as a means to investigate the role of endosymbionts in reproductive phenotypes. Wolbachia was the only symbiont found and we then focused on its worldwide distribution and diversity in natural populations of W. auropunctata. Using a multilocus scheme, we further characterized the Wolbachia strains present in these populations. We found that almost all the native sexual populations and only a few clonal populations are infected by Wolbachia. The presence of similar Wolbachia strains in both sexual and clonal populations indicates that they are probably not the cause of the reproductive system polymorphism. The observed pattern seems rather associated to the invasion process of W. auropunctata. In particular, the observed loss of Wolbachia in clonal populations, that recurrently emerged from sexual populations, likely resulted from natural heat treatment and/or relaxed selection during the shift in habitat associated to the invasion process.
Wasmannia auropunctata (Hymenoptera: Formicidae): ?unicolonial o multicolonial? en el valle geográfico del río Cauca
SALGUERO R.,BEATRIZ; ARMBRECHT,INGE; HURTADO T.,HERNANDO; ARCILA C.,áNGELA MARíA;
Revista Colombiana de Entomología , 2011,
Abstract: with the aim of identifying little fre ant wasmannia auropunctata?s social structure in drastically disturbed environments, we modeled the spatial distribution of this species in two patches of dry forest with contrasting levels of disturbance, at southand and north of the cauca river valley, a region for which w. auropunctata is considered native with a multicolonial social structure. for the analysis, we took into account both, population density and nests/m2, in biotopes: edge, interior forest and pasture. the modeling was framed in the feld of geostatistics, were, by the estimation of semivariograms? models and parameters, the spatial continuity of variables we were interested in was defined. they were used to interpolate and construct the maps for those regions not sampled all of this through kriging. it was found that the spatial distribution model was well described by spherical and exponential semivariograms, which explained the pattern of spatial autocorrelation. interpolation maps of workers per bait and nests/m2 allowed usto show that the little fre ant has an unicolonial social structure in the patch of san julian?s forest, at south of the valley. that was as-sociated with a greater degree of disturbances, which may justify their low intraspecific aggression in its native range. in contrast, in the alejandria?s forest patch situated at north of the department and which exhibited a lower disturbance, it introduced a social structure multicolonial and high intraspecific aggression.
Composición de hormigas e interacciones competitivas con Wasmannia auropunctata en fragmentos de Bosque seco Tropical Ant composition and competitive interactions with Wasmannia auropunctata in Tropical Dry Forest fragments
RAFAEL ACHURY,PATRICIA CHACóN DE ULLOA,áNGELA MARíA ARCILA
Revista Colombiana de Entomología , 2008,
Abstract: La perturbación incrementa la posibilidad de dominancia por parte de la peque a hormiga de fuego Wasmannia auropunctata (Formicidae: Myrmicinae), especie indicadora de baja diversidad de la comunidad de hormigas en Bosque seco Tropical del valle geográfico del río Cauca (Colombia). Para estudiar las relaciones de competencia interespecífica que involucran a dicha especie, se hicieron experimentos con cebos de atún sobre el suelo en cuatro localidades que conservan fragmentos de bosque seco: Alejandría, El Medio, El Vínculo y San Julián. En cada localidad se distinguieron tres biotopos: interior de bosque, borde de bosque y matriz (ca a de azúcar o potrero). Con la información obtenida a partir de la composición de hormigas en los cebos, se calcularon índices de habilidad competitiva. La atracción a cebos fue del 91%, registrándose 66 especies de hormigas en 30 géneros. La composición de hormigas varió dependiendo principalmente de las condiciones de la localidad. Las mirmicinas Pheidole, Solenopsis y Crematogaster presentaron la mayor interacción con W. auropunctata y la partición del cebo estuvo influenciada principalmente por la clase de biotopo. El aprovechamiento del cebo por otras especies fue determinado por la abundancia de W. auropunctata; si en el cebo hay más de 500 obreras en promedio, el recurso no será compartido. W. auropunctata sobresale como especie dominante en la cuenca alta del río Cauca y esto lo logra principalmente por mecanismos de competencia por explotación, permitiéndole un rápido aprovechamiento de los recursos al reclutar gran número de obreras. Disturbance increases the probability of dominance by the little fire ant Wasmannia auropunctata (Formicidae: Myrmicinae), an indicator species of low diversity ant communities in Tropical Dry Forest fragments of the Cauca River Valley (Colombia). In order to study interactions of interspecific competition involving this species, we conducted experiments with soil-surface tuna-baits at four localities: Alejandría, El Medio, El Vínculo and San Julián. Three biotopes were distinguished at each locality: forest interior, forest margin and their surrounding matrices (sugar cane or pasture). Based on information obtained from the composition of ants at the baits, competition ability indices were calculated. Attraction to the baits was 91%, for a total of 66 species in 30 genera. Species composition was mainly influenced by locality conditions. The myrmicines Pheidole, Solenopsis and Crematogaster had the greatest interaction with W. auropunctata and partitioning of the baits was mostly inf
Wasmannia auropunctata (Hymenoptera: Formicidae): unicolonial o multicolonial? en el valle geográfico del río Cauca Wasmannia auropunctata (Hymenoptera: Formicidae): Unicolonial o multicolonial?: in the valley Cauca river
BEATRIZ SALGUERO R.,INGE ARMBRECHT,HERNANDO HURTADO T.,áNGELA MARíA ARCILA C.
Revista Colombiana de Entomología , 2011,
Abstract: Con el objetivo de identificar la estructura social de la peque a hormiga de fuego Wasmannia auropunctata, en ambientes drásticamente perturbados, se modeló la distribución espacial de esta especie en dos parches de bosque seco con grados de perturbación contrastantes, ubicados al sur y norte del valle geográfico del río Cauca, regiones para las cuales W. auropunctata es considerada nativa con estructura social multicolonial. Para los análisis se tuvieron en cuenta las variables densidad poblacional y nidos/m2 en los biotopos: borde, interior de bosque y potrero. la modelación estuvo enmarcada en el campo de la geoestadística, donde se estimaron los modelos de semivariogramas y parámetros asociados, que definieron la continuidad espacial de las variables de interés y que fueron utilizados para la interpolación y construcción de mapas en regiones del espacio no muestreadas, a través del krigeado. Se encontró que la distribución espacial estuvo bien descrita por modelos de semivariogramas esféricos y exponenciales, que explicaron el patrón de autocorrelación espacial. los mapas de interpolación de obreras por cebo y de nidos/m2, permitieron mostrar como la peque a hormiga de fuego presenta una estructura social unicolonial en el parche de bosque de San Julián, al sur del departamento del Valle asociado a un mayor grado de perturbación, lo que puede llegar a justificar su baja agresividad intraespecífica en su rango nativo. En contraste, en el parche de bosque de Alejandría al norte del departamento y con un menor grado de perturbación, presentó una estructura social multicolonial con alta agresión intraespecífica. With the aim of identifying little fre ant Wasmannia auropunctata’s social structure in drastically disturbed environments, we modeled the spatial distribution of this species in two patches of dry forest with contrasting levels of disturbance, at southand and north of the Cauca river valley, a region for which W. auropunctata is considered native with a multicolonial social structure. For the analysis, we took into account both, population density and nests/m2, in biotopes: edge, interior forest and pasture. The modeling was framed in the feld of geostatistics, were, by the estimation of semivariograms’ models and parameters, the spatial continuity of variables we were interested in was defined. They were used to interpolate and construct the maps for those regions not sampled all of this through kriging. it was found that the spatial distribution model was well described by spherical and exponential semivariograms, which explained the pattern
Genetic variability of native populations of Wasmannia Forel (Hymenoptera: Formicidae) and their biogeographical implications
Souza, Ana L B;Tavares, Mara G;Serr?o, José E;Delabie, Jacques H C;
Neotropical Entomology , 2009, DOI: 10.1590/S1519-566X2009000300013
Abstract: wasmannia auropunctata (roger) and wasmannia rochai forel are economically important ants in the southeast and southwest regions of bahia state, brazil. randomly amplified polymorphic dna (rapd) markers were used to distinguish and analyze the genetic variability of populations of both species from ilhéus, jequié, ba and french guyana. the genetic distances among w. auropunctata and w.rochai populations (55.8-71.4%) suggest genetic differentiation among them. wasmannia auropunctata populations from sugarcane and banana plantations in jequié were the most distant genetically (30.1-46.3%) and may represent populations restricted to isolated fragments. the high genetic distances among w. auropunctata populations from ceplac experimental areas, in ilhéus (26.8-34.6%) and the other populations from ilhéus (23.3-40.8%), suggest a multicolonial structure of w. auropunctata in southeast bahia. the genetic proximity among the w. auropunctata populations from cocoa (14.1%) and coconut plantations (18.5%) in ilhéus with the populations from the french guyanan forests suggest that there was recent and large expansion of populations derived from a single population, that are today distributed in habitats with similar environmental characteristics. the high polymorphism and the estimated heterozygosity values for the two species suggest that we studied native w. auropunctata and w.rochai populations.
Potential heterogeneity in crustacean zooplankton assemblages in southern chilean saline lakes
De los Rios-Escalante, P;Gajardo, G.;
Brazilian Journal of Biology , 2010, DOI: 10.1590/S1519-69842010000500016
Abstract: the chilean saline lakes are distributed mainly in the atacama desert in northern chile and the southern patagonian plains. the scarce studies are restricted mainly to northern chilean saline lakes, and these revealed that the main component in these ecosystems are the halophylic copepod boeckella poopoensis marsh 1906, or the brine shrimp artemia franciscana (kellog, 1906), and both species do not coexist. the present study consisted of field observations in zooplankton assemblages in southern chilean saline lakes (51-53 os). these first observations revealed three different patterns, one saline lake only with a. persimilis (piccinelli and prosdocimi, 1968), a second lake only with b. poopensis, and a third lake with a. persimilis, b. poopoensis and unidentified harpacticoid copepod. these results are different in comparison with the observations in the literature that described the non-coexistence between b. poopoensis with brine shrimps. ecological and biogeographical topics were discussed.
Environment heterogeneity and seasonal effects in ground-dwelling ant (Hymenoptera: Formicidae) assemblages in the Parque Estadual do Rio Doce, MG, Brazil
Coelho, Igor R.;Ribeiro, Sérvio P.;
Neotropical Entomology , 2006, DOI: 10.1590/S1519-566X2006000100004
Abstract: this work aimed to explore the response of ant species assemblage to contrasting types of forests in a semideciduous stationary rainforest, in the parque estadual do rio doce, south eastern brazil. we compared antropomorphic borders of this park and natural ecotones, such as lake margins continuous with forests, as well as preserved forests far from ecotones. we investigated whether ground-dwelling ant species richness, abundance and composition would change according to forest types and ecotones. we expected greater species richness in interior tall forest, compared with low forest or ecotone habitats. in addition, we tested the effect of climate seasonality on ant assemblages found in each studied vegetation type. each forest type was surveyed based on a minimum transect sampling unit of 150 m long summing up 30 pit-falls per unit. two sampling events, one in dry season(september of 2001) and another in the rainy season (january of 2002) were performed. for both seasons, tall forest presented greater total number of ant species, however lower mean ant species and abundance per trap than other forest types, thus corroborating the prediction that ecotones might present high alpha diversity. mean species richness and abundance did not differ between interior low forest and lake edge, or between these habitats and reserve border. in general, species composition were not clearly defined by forest types. results here found suggest that species loss or community dominance by generalist species, eventually due to deforestation, is probably a much greater problem than previously thought. however, to understand patterns of insect species diversity and distribution in tropical ecosystem should be taken in account much more comprehensive, spatially explicit sampling designs.
Changes in Mangrove Epifaunal Assemblages Caused by Forest Logging during Hunting of the Neotropical Cormorant (Phalacrocorax brasilianus) on the Colombian Pacific Coast  [PDF]
Carlos Andrés Satizabal R., Jaime Ricardo Cantera Kintz, Paula Cristina Sierra-Correa
Open Journal of Marine Science (OJMS) , 2012, DOI: 10.4236/ojms.2012.24018
Abstract: Although the importance of mangroves is clearly recognized around the world, these ecosystems are being strongly altered by the logging of their forests for multiple purposes. The Colombian Pacific coast is not an exception to this situation, and apart from the traditional logging of wood, the hunting of the Neotropical Cormorant or Pato-cuervo (Phalacrocorax brasilianus), an activity largely unknown but widespread in the region, is also causing the logging of great extensions of mangroves. The aim of this research was to determine if the assemblages of mollusks and crustaceans of these mangroves are being affected by the hunting of the cormorant. To answer this question, quantitative samplings were realized in four transects in logged and unlogged mangrove areas on the southwestern coast of the Colombian Pacific and diversity, equitability and dominance of macrofaunal assemblages of mangroves were calculated. The data show that although significant differences between diversity indices were not found, there were important differences in equitability (total J’: 0.55 in T1, 0.77 in T2, 0.46 in T3 and 0.65 in T4), specific dominance, and composition of species (T1: 11 species, T2: 13, T3: 9 and T4: 11) between logged and unlogged areas. Based on these results, although forest structure and interstitial salinity were different among transects, we conclude that the present practice of exploitation of the Neotropical Cormorant is affecting the epifaunal populations of mangroves, causing changes in the composition and dominance of species.
Formigas (Hymenoptera: Formicidae) como vetores de bactérias em dois hospitais do município de Divinópolis, Estado de Minas Gerais
Santos, Paula Fernandes dos;Fonseca, Alysson Rodrigo;Sanches, Newton Moreno;
Revista da Sociedade Brasileira de Medicina Tropical , 2009, DOI: 10.1590/S0037-86822009000500016
Abstract: the presence of ants (hymenoptera: formicidae) in hospital environments may constitute a public health problem, especially since they are mechanical vectors for pathogenic organisms. this study aimed to survey the ant populations and analyze the presence of bacteria associated with them in two medium-sized regional hospitals in the municipality of divinópolis, minas gerais, brazil. specimens were collected every monthly over a six-month period. the following ant species were found: pheidole sp1 and sp2, linepithema humile, wasmannia auropunctata, camponotus sp1 and sp2, odontomachus sp, solenopsis sp, acromyrmex sp and tapinoma melenocephalum. it was observed that these ants mechanically transported pseudomonas aeruginosa, enterococcus, streptococcus, escherichia coli and non-pathogenic and pathogenic staphylococcus. these results show the propensity for occurrences of hospital infections at these sites caused by mechanical transmission of pathogens by ants.
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