黄瓜地烟粉虱空间格局参数特征及其应用

Study on Parameter Characters of Spatial Distribution Pattern and Its Aplications of Bemisia tabaci in the Cucumber-Fields

通过对秋季黄瓜苗期烟粉虱不同发生密度地块调查,取得了9组样本资料,应用聚集度指标法、Iwao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黄瓜秧苗上呈聚集分布,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(X-<3.7049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(X-≥3.7049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。在此基础上,通过几种抽样方式比较测定,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/D2[5.2851/X-+0.1063],Tn=5.2851/[D02-0.1063/n]。

Nine sample materials were investigated By different density occuITence of Bemisia tabaci in cucumber -fields in autumn. Three methods of aggregated indices ancl Iwao＇s way （ regressive relation by M ＊ - m） ancl power law of Taylor were usecl to test the spatial distribution pattern. The results showed as followings ： the occurrence of adult on the young cucumber plants belonged to the aggregation distribution. The concentration class increased By the population density. The causes of concentration were tested By Blackith＇s method. When X 〈 3. 7049, their aggregation was caused By some environmental factors such as climate, planting, ancl growth ancl so on; when X ≥3. 7049, their aggregation was caused By their behavior and environmental conditions. Based on this distribution pattern a suitable sampling mocle has Been provided , the errors of several sampling Bemisia tabaci population in the field were compared , ancl the five points method was the best. The model for determining the Best optimum theoretical sampling number and the Best optimum sequential sampling are proposed. The model are as follows ： N = 1/D2 [ 5. 2851/X ＋ 0. 1063 ], Tn = 1. 0079/[ D0^2 - 0. 0633/n ].