Spatial distribution of adults and nymphs of stink bug, Edessa meditabunda (Fabricius, 1974) (Hemiptera: Pentatomidae) on soybean Bt and non-Bt

Abstract

Knowledge of the dispersion of adults and nymphs of Edessa meditabunda in soybean model is needed to determine the control actions and thus enable proper use of strategies to avoid losses in production. This research aimed to conduct probabilistic analysis of the spatial distribution patterns of adults and nymphs of E. meditabunda in two regions in soybean Bt and non-Bt. For the evaluations, the method of cloth-to-beat was used, where one sample per plot was collected randomly from each experimental area. Evaluations were performed at 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91 and 98 days after emergence. For data analysis, the rates of dispersion (variance/average Morisita index and exponent k Negative Binomial Distribution) and theoretical frequency distributions (Poisson, Binomial and Negative Binomial Positive) at 5% probability were calculated. The peak population of adults and nymphs of E. meditabunda was observed in the reproductive stage of soybean Bt and non-Bt in Dourados and Douradina. From the results obtained, it can be concluded that the Bt technology had the spatial arrangement of adults and nymphs of E. meditabunda, and is set in probabilistic arrangements with negative binomial distribution (aggregate) in the two regions surveyed. In non-Bt soybeans for adults and nymphs of E. meditabunda, spatial arrangements had set in probabilistic arrangements of positive and negative binomial distribution (uniform), as the days after emergence, for the region of Dourados and Douradina.