番茄地烟粉虱空间格局参数特征及其应用

2006年通过对春季番茄烟粉虱不同发生密度地块调查,取得了11组样本资料,应用聚集度指标法I、wao法和Taylor法等对其空间分布型进行测定检验,结果表明烟粉虱成虫在番茄上呈聚集分布,其聚集度是随着种群密度升高而增加。其聚集原因经Blackith种群聚集均数测定,当m<2.9638时,其聚集是由于某些环境如气候、栽培条件、植株生育状况等所引起的;当m≥2.9638时,其聚集是由害虫本身的聚集行为与环境条件综合影响所致。比较几种抽样方式以五点式为最佳,并提出了最佳理论抽样数和最佳序贯抽样模型:N=1.962/D21.007 9/m+0.0633],Tn=1.0079/D20-0.0633/n]。

Characteristics of the parameters of spatial distribution pattern of Bemisia tabaci in tomato fields and their applications

Occurrence of Bemisia tabaci in tomato fields was investigated to reveal their distribution and population behavior in 2006.Three methods of aggregation indices and Iwao's way(regressive relation by M*-m) and power law of Taylor were used to test the spatial distribution pattern of B.tabaci in tomato fields.The results showed that the population of B.tabaci belonged to the pattern of aggregated distribution.According to Blackith's test method,when m<2.963 8,their aggregation might be caused by some environmental factors such as climate,planting and growth and so on,but when m=2.963 8,their aggregation might be caused by their behavior and environmental conditions.Based on this distribution pattern,when the most fit scale were ensured through the Iwao's M*-m regression equation,a suitable sampling mode has been provided.The errors of several B.tabaci populations sampled in the fields were compared,and the five-point method was the best.The model for determining the optimum theoretical sampling number and the optimum sequential sampling was proposed,which was as followed: N=1.962/D21.007 9/m 0.063 3] and Tn=1.007 9 /D20-0.063 3 /n].