Amostragem sequencial de percevejos fitófagos (Hemiptera: pentatomidae) em diferentes sistemas de produção de soja

Abstract

The stink bugs are important pests of soybeans, and the knowledge of their biology and distribution in the crops are indispensable to perform sampling and determine the level of control. In the brazilian midwest region of hot weather the predominant species is Euschistus heros, but species like Dichelops melacanthus, D. furcatus and Edessa meditabunda are also frequently found, and the complex of these species has great economic importance for agricultural production in the region. The objective was to study the spatial distribution of the complex of stink bugs in different soybean production systems and develop a sequential sampling plan. The experiment was conducted in Maracajú, MS, Brazil, during the growing season 2012/13, with the soybean cultivars BRS 284 and SYN 1163 RR, in an experimental area, consisting of six fields (two soybean cultivars x three growing systems ). Each course consisted of an area of 2025 m2 (45 mx 45 m) divided into 100 plots (4.5 mx 4.5 m). Samples were collected weekly using beat cloth at one point per plot. For statistical analysis we used the dispersion index (ratio variance / media, Morisita index, exponent k of the negative binomial and Green coefficient); and probabilistic methods of frequency setting (negative binomial and Poisson). Stink bugs is unique populations of E. heros or the stink bug complex, presented a clustered arrangement in the field regardless of the management system. The adjustments in the number of adults and nymphs were collected the distribution of negative binomial probabilities. There was no difference in the behavior of adults and nymphs on cultivars used. A sequential sampling plan was developed for the complex of stink bugs, crops destined for the production of grains and crops for seed production.