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[目的]研究玉米田四代棉铃虫老熟幼虫空间分布型。[方法]于2009年8～9月,对第4代棉铃虫不同发生密度地块进行调查,取得了6组样本资料,应用聚集度指标法、Iwao法和Taylor法等7种指标分析,对其空间分布型进行检验。[结果]聚集度指标的检验结果表明:所有样地MooreI<0,Lloyodm*/m<1,KunoCa<0,扩散系数C<1,扩散型指数Iδ<1,负二项分布,K<0,表明棉铃虫老熟幼虫在夏玉米上均呈均匀分布。棉铃虫第4代老熟幼虫在夏玉米上的Iwao回归方程为m*=0.0906+0.7669m,r=0.9863;说明棉铃虫分布的基本成分为单个个体,老熟幼虫在夏玉米上呈均匀分布。利用公式N1=(1.0906/m-0.2331)/D2即可求出棉铃虫第4代老熟幼虫在玉米上不同密度下的最适抽样数。[结论]研究结果为准确估值棉铃虫种群数量及变动规律,为预测及防治棉铃虫提供依据。
[Objective] The research aimed to study the spatial distribution of mature larvae of four generations of cotton bollworm in corn field. [Method] From August to September, 2009, the investigation was conducted on the plots of the density of the 4th generation of cotton bollworm. Six sample data were obtained. Based on the analysis of seven indicators, such as the degree of aggregation index method, the Iwao method and the Taylor method, Its spatial distribution test. [Result] The test results of aggregation degree index showed that all samples had negative binomial distribution, MooreI <0, Lloyodm * / m <1, KunoCa <0, diffusivity C <1, , Indicating that the mature cotton bollworm larvae were evenly distributed on summer corn. The Iwao regression equation of the fourth generation of mature larvae of H. armigera on summer maize was m * = 0.0906 + 0.7669m, r = 0.9863. It showed that the basic components of the distribution of H. armigera were single individuals and the mature larvae were evenly distributed on summer maize . Using the formula N1 = (1.0906 / m-0.2331) / D2, we can get the optimum sampling number of 4th generation mature cotton larvae in different density of corn. [Conclusion] The result of the research was to accurately estimate the population and variation of cotton bollworm population, and to provide the basis for prediction and control of cotton bollworm.