Abstract The study was carried out on an agroecological property located in Cologne São Manoel, 8th district of Pelotas, RS, Brazil. Anochetus neglectus Emery, 1894 was collected in an area of peach orchard that has been under an agroecological system for 18 years. This record expands the area of occurrence and distribution of this rare species in the Neotropical Region.

Abstract The objective of the study was to compare the richness and diversity of ant assemblages in an agroecological system under peach orchard, conventional system under peach orchard cultivation and native vegetation in rural properties located in a Pampa Biome. The study was conducted in four samplings in 2017: 1st and 09th March (summer); 24th and 31st July (winter); and four samplings in 2018: 23rd and 30th January (summer); 31st July and 07th August (winter). Pitfall traps were used. The assemblages were characterized and compared using richness, number of occurrences of ants, Shannon diversity (H’), equitability, rarefaction analysis and Chao 1. The association of the species with the samples was evaluated by a Principal Component Analysis (PCA). The agroecological system had the highest number of occurrences, while the conventional orchard the lowest number. Richness and abundance were greatest during the summer. The conventional peach orchard obtained the lowest H’ for both seasons when compared to the agroecological orchard and native vegetation. The PCA explained 77.40% of the occurrence of ants in the environments and in the seasons. The results found demonstrated that conservationist systems tend to harbor greater wealth and diversity of ant assemblages, as well as occurring in native áreas.

Abstract The presence of ants in school kitchens and canteens may pose a risk of food contamination. The present study aimed to evaluate the potential of the ants as carriers of microorganisms indicating hygienic and sanitary conditions in school kitchens and canteens in the western region of Santa Catarina. Ten samples were collected with up to ten ants in the kitchen and canteen environments in nine urban schools. The ants were evaluated using microbiological analyses regarding Staphylococcus aureus, aerobic mesophilic bacteria, total coliforms and thermotolerant coliforms/Escherichia coli. Twenty ant species were sampled. Four species presented counts for S. aureus, eight for aerobic mesophilic bacteria and three for total coliforms. The results evidenced the potential of ants as indicators of contamination and the risk of ants to carrier microorganisms in school environments and an important diversity occurring in indoor environments.

Resumen La utilización de productos sintéticos en el control de mosquitos Aedes aegypti ha inducido en sus poblaciones la resistencia e impone riesgos a la fauna y flora. En este estudio fueron evaluados el efecto del extracto del fruto de Melia azedarach (Meliaceae) obtenido a través del método de extracción con dióxido de carbono supercrítico y el potencial larvicida del Bacillus thuringiensis var. israelensis (Bti) sobre los inmaduros de A. aegypti en condiciones de laboratorio. Los ensayos fueron realizados en vasos desechables con 100, 250, 500, 750, 1.000 and 2.000 μg/ml de concentración de extracto de M. azedarach, y 0,0005, 0,001, 0,0015, 0,002 y 0,0025 g/L de VectoBac WG®, y como controles, agua. Para cada vaso fueron adicionadas 10 larvas activas. Los resultados fueron comparados considerando el número de larvas vivas contadas a diario durante 72 h. La eficiencia de los tratamientos probados fue calculada por la ecuación de Abbott. El extracto supercrítico de M. azedarach presentó acción positiva para las concentraciones de 1.000 y 2.000 μg/mL. Para el Bti la eficiencia fue del 100 % en las primeras 24 h. Los resultados indican la posibilidad del control poblacional del A. aegypti a partir del extracto supercrítico de M. azedarach.

Abstract The intense use of synthetic products for the control of Aedes aegypti has led to the development of resistance and imposes health risks to other flora and fauna. This study assessed the larvicidal potential of Melia azedarach (Meliaceae) fruit extract obtained by the supercritical carbon dioxide extraction method and Bacillus thuringiensis var. israelensis (Bti) on second and third instar A. aegypti larvae under laboratory conditions. The assays were performed in disposable cups containing 100 250, 500, 750, 1,000 and 2,000 μg/ml extracts of M. azedarach, and 0.0005, 0.001, 0.0015, 0.002, and 0.0025 g/L of VectoBac WG®; the controls contained only water. Ten active larvae were added to each well, and the number of living larvae was counted each day for 72 h. Treatment efficiency was calculated using Abbott's equation. Insecticidal efficiency increased with M. azedarach extract concentration, with significant effects in the 1,000 and 2,000 μg/mL concentration range. Bti efficiency was 100 % in the first 24 h. The results indicate the possibility of A. aegypti population control using supercritical extracts of M. azedarach.

ABSTRACT Ant diversity is influenced by the structural complexity of the environment. Ants are thus an ecologically important group due to their potential to serve as indicators of environmental quality. The objective of this study was to evaluate ant diversity in areas with different land use histories and thus, within different stages of regeneration in the Permanent Preservation Area of the Foz do Chapecó Hydroelectric Plant reservoir. Ant assemblies among sample sites were compared using rarefaction analysis, and estimated richness, frequency of occurrence, and relative abundance were calculated. Associations between species and sample sites were evaluated using Principal Component Analysis (PCA). We identified 55 species in total from 24 genera, distributed among seven subfamilies. Eight species had positive associations with sample sites. Estimates indicated that ant richness may be up to 21.4% greater than that observed. This study presents an inventory of species capable of colonizing environments undergoing natural regeneration processes, and aids our understanding of ecological recovery dynamics in protected areas near hydroelectric plant reservoirs southern Brazil.

A diversidade e a estrutura das comunidades biológicas são afetadas pela intensificação das atividades antrópicas. Este estudo avaliou a estrutura das assembleias de formigas de quatro tipos de ambientes ao longo de um gradiente de intensidade de perturbação antrópica em dez cidades situadas na região austral do Domínio Mata Atlântica. Os ambientes avaliados foram: fragmentos florestais, áreas verdes, escolas e centros de reciclagem. Foram realizadas duas amostragens durante o ano de 2011, uma em fevereiro e março e outra em outubro e novembro. Para a comparação das assembleias de formigas foi desenvolvida uma análise de rarefação baseada no número de ocorrências nos quatro tipos de ambientes. A composição das assembleias foi verificada através de um teste de aninhamento utilizando a métrica a NODF. A associação das espécies de formigas com os ambientes amostrados foi obtida por meio de uma Análise de Espécies Indicadoras (ISA). Foram encontradas diferenças significativas de riqueza e de abundância entre os ambientes, mostrando uma tendência de redução nos ambientes escolares e centros de reciclagem em relação aos fragmentos florestais e áreas verdes. Observou-se um padrão de aninhamento ao longo do gradiente, ou seja, as assembleias pertencentes aos ambientes sob maior pressão antrópica são subconjuntos da mirmecofauna dos ambientes mais conservados. Não houve alteração da composição das assembleias, e sim uma perda importante de espécies de um ambiente para outro. Os fragmentos florestais apresentaram o maior número de espécies indicadoras (12), seguido pelas áreas verdes (4) e escolas (3). Os resultados podem ajudar na implementação de políticas de desenvolvimento urbano e na elaboração de planos de conservação.

Ant community structure (Hymenoptera: Formicidae) in four environments with different levels of human disturbance: The diversity and biological communities structure are affected by the intensification of human activities. This study evaluated the ant community structure from four types of environments with different levels of human disturbance intensity at ten cities in the southern region of the Atlantic Forest Biome. The environments were: forest fragments, green areas, schools, and recycling centers. Two samplings were conducted in 2011, one in February and March and another in October and November. To compare the ant assemblages, it was performed a rarefaction analysis based on occurrences number. The composition of the assemblages was evaluated by a nestedness test using the NODF metric. The association of ant species with the environments was obtained by an Indicator Species Analysis (ISA). Significant differences in richness and abundance were found between the environments, showing a downward trend in schools and recycling centers in relation to forest fragments and green areas. There was a nesting pattern along the gradient, ie the assemblies belonging to the high human pressure environments are subsets of the conserved ones. There was no change in the composition of the assemblies, but a significant loss of species from one environment to another. The forest fragments had the highest number of indicator species (12), followed by green areas (4) and schools (3). The results can help in the implementation of urban development policies and development of conservation plans.