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禾谷黍缢管蚜在小麦抽穗到灌浆期田间呈聚集分布。应用Ⅰwao x-x回归法和Southwood公共Kc值法求得理论抽样数模型,从而导出在不同置信度t、不同蚜口密度X(头/株)和不同允许误差D下的理论抽样数n。 当采用Ⅰwao及WilIson等(1983)提出的序贯抽样法时,得到该蚜虫的两个序贯抽样模型。 结合Ⅰwao和willson的二模型,获得该蚜虫的Ⅰwao-Willson复合序贯抽样法,从而在某些情况下,大大地减少了抽样数。
Aphis gossypii Aphis gossypii in the wheat heading stage to filling the field was aggregated distribution. The theoretical sampling number model was obtained by using Iwao x-x regression method and Southwood public Kc value method to derive the theoretical sampling number n under different confidence levels t, aphid population density X (head / plant) and different allowable errors D. Two sequential sampling models of this aphid were obtained when the sequential sampling method proposed by Iwao and WilIson et al. (1983) was used. Combining the two models of Iwao and Willson, the Iwao-Willson compound sequential sampling method for the aphid is obtained, which in some cases greatly reduces the number of samples.