Species Richness and Community Composition of Ants and Beetles in Bt and non-Bt Maize Fields.

Insect-resistant genetically modified (GM) plants have been cultivated in several countries on a large scale. These plants express the Cry toxins from the bacterium Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt), which confers target-pest resistance to plants. Studies on the effects of GM plants on nontarget organisms are important to assess the technology's impact on biodiversity. The objective of this study was to determine whether there are differences in the species richness and composition of ants and ground beetles in Bt maize (four different toxins: Cry1Ab, Cry1F, and Cry1A.105/Cry2Ab2) and conventional isoline (non-Bt) fields, in the first (summer) and second (winter) cropping seasons in 13 localities of Mato Grosso do Sul State, Brazil, over a 2-yr period (2009-2011). The assessment of Coleoptera and Formicidae species was performed using pitfall traps placed in fields throughout the period of vegetative growth and maturation of plants. Data were analyzed using faunistic indices of species richness, ordination by nonmetric multidimensional scaling, and multivariate analysis of variance. No statistically significant difference was found in the species richness of ant and ground beetle communities when comparing sites of Bt with those of non-Bt maize. Overall, Bt technology did not affect the composition of ant and ground beetles; however, municipality and cropping season exerted influence on the beetle composition. Some species were only observed in the first crop, whereas others were only observed in the second crop. This research suggests that Bt maize does not affect ant and ground beetle populations differently from its isoline.

Cupins em residências de um bairro em Cáceres, Mato Grosso / Termites in residences of a neighbourhood in Cáceres, Mato Grosso

O objetivo deste estudo foi verificar a abundância de cupins e a percepção de moradores sobre a atuação desses insetos como pragas. O trabalho foi conduzido em quatro residências do bairro Jardim Paraíso, em Cáceres, Mato Grosso. Para isso, foram realizadas inspeções em março, maio, agosto e novembro de 2004 e fevereiro de 2005 por meio de coleta manual (dentro das residências e em árvores nos quintais) e da aplicação de questionários com os moradores para verificar a opinião deles sobre a atuação dos cupins. Foram identificadas quatro espécies: Nasutitermes coxipoensis(48,2%), Nasutitermes sp. (31%), Microcerotermes strunckii (7%) e Heterotermes tenuis (13,7%). Tanto os gêneros (χ2 = 7,880; GL = 8; α = 0,445) quanto as espécies (χ2= 20,542; GL = 12; α = 0,058) ocorreram em proporções similares durante o ano, demonstrando que não existe uma relação entre os períodos de coleta e a abundância de insetos. Neste estudo, 50% dos moradores não consideraram os cupins como pragas em suas residências, provavelmente porque na maioria dos casos esses insetos foram encontrados em árvores. Devido ao baixo número de casas investigadas, mais estudos são necessários para o melhor entendimento sobre a ocorrência de cupins.(AU)

The objective of this study was to evaluate the abundance of termites and the perception of residents about those insects as pests. This study was conducted inside and in the surroundings of four houses in the neighbourhood Jardim Paraíso, in Cáceres, Mato Grosso. Inspections were carried out in March, May, August and November, 2004 and February. 2005, by manual collection (inside the houses and on trees of the backyards). Questionnaires were used to check the opinions of the residents about these insects. Four species were identified: Nasutitermes coxipoensis (48.2%), Nasutitermes sp. (31%), Microcerotermes strunckii (7%) and Heterotermes tenuis (13.7%). The genera (χ2 = 7.880; GL = 8; α = 0.445) and the species (χ2 = 20.542; GL = 12; α = 0.058) occurred in similar proportions. No significant relation was found between the collection periods and the abundance of the insects. In this study, 50% of the residents did not consider the termites as pests, probably because in most cases (56.4%) termites were found only in the trees. Due to the small number of investigated houses, further studies are necessary for a better understanding of the termite incidence.(AU)