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.