Abstract
It is important to quantify the population of stink bugs in the soybean, in order to determine the actions which are necessary for their control to protect the crop from losses in production, together with a reduction in cost and less environmental impact. The objectives of this study were to determine the sample size (the number of sampling points) needed to estimate the average population density of the bugs, and to verify the variability in sample size for the phases and species of the bugs and the phenological stages of the plants. In an area of 6.16 ha of soybeans, a grid of 154 sampling points, spaced 20 × 20 m apart, was laid out. Population-density data were collected for nymphs and adults of the species Dichelops furcatus (Fabricius, 1775), Piezodorus guildinii (Westwood, 1873), Edessa meditabunda (Fabricius, 1794), Nezara viridula (Linnaeus, 1758), Euschistus heros (Fabricius, 1794) and Chinavia sp. (Say, 1832) employing a vertical beat sheet at 14 different phenological stages. Measurements of central tendency and variability, the Morisita index and the k parameter of negative binomial distribution were all calculated. Homogeneity of variances was verified and the sample size calculated. There is variability in the sample size when estimating the average population density of bugs across the phases and species of bug and the phenological stages of the soybean. Smaller sample sizes are necessary for the nymphs of P. guildinii and the final phenological stages (R6, R7.1, R7.3 and R8.2). Thirty-six sampling sites are enough to estimate the average population density of bugs in the final phenological stages (R6, R7.1, R7 .3 and R8.2) at an error of estimation equal to 30% of the estimated mean and at a level of confidence of 95%.
Highlights
It is important to quantify the population of stink bugs in the soybean, in order to determine the actions which are necessary for their control to protect the crop from losses in production, together with a reduction in cost and less environmental impact
Os objetivos deste trabalho foram determinar o tamanho de amostra para a estimação da média de densidade populacional de percevejos e verificar a variabilidade do tamanho de amostra entre as fases e as espécies de percevejos e os estádios fenológicos
Foram coletados dados de densidade populacional de percevejos ninfas e adultos das espécies Dichelops furcatus (Fabricius, 1775), Piezodorus guildinii (Westwood, 1873), Edessa meditabunda (Fabricius, 1794), Nezara viridula (Linnaeus, 1758), Euschistus heros (Fabricius, 1794) e Chinavia sp. (Say, 1832), por meio do pano-de-batida vertical, em 14 estádios fenológicos
Summary
It is important to quantify the population of stink bugs in the soybean, in order to determine the actions which are necessary for their control to protect the crop from losses in production, together with a reduction in cost and less environmental impact. There is variability in the sample size when estimating the average population density of bugs across the phases and species of bug and the phenological stages of the soybean. Os objetivos deste trabalho foram determinar o tamanho de amostra (número de pontos amostrais) para a estimação da média de densidade populacional de percevejos e verificar a variabilidade do tamanho de amostra entre as fases e as espécies de percevejos e os estádios fenológicos. Foram coletados dados de densidade populacional de percevejos ninfas e adultos das espécies Dichelops furcatus (Fabricius, 1775), Piezodorus guildinii (Westwood, 1873), Edessa meditabunda (Fabricius, 1794), Nezara viridula (Linnaeus, 1758), Euschistus heros (Fabricius, 1794) e Chinavia sp. Há variabilidade do tamanho de amostra para a estimação da média de densidade populacional de percevejos entre as fases e as espécies de percevejos e entre os estádios fenológicos da soja. Trinta e seis pontos amostrais são suficientes para estimar a média de densidade populacional de percevejos, para um erro de estimação igual a 30% da média estimada, com grau de confiança de 95%, nos estádios fenológicos finais (R6, R7.1, R7.3 e R8.2)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
