凉山烟田烟粉虱(MED隐种)成虫空间分布型及序贯抽样技术

Spatial distribution pattern of Bemisia tabaci MED adults in tobacco fields in Liangshan and sequential sampling technique

运用2种回归方法和8个聚集度指标对四川凉山烟田烟粉虱盛发期种群的空间格局进行了研究。结果表明,烟粉虱种群呈聚集分布,聚集强度不随种群密度的变化而变化,其聚集原因是由环境因素所导致;通过种群密度与聚集度指标相关性分析表明,用平均拥挤度(m*/m)、负二项分布指标(K)及久野指数(CA)分析烟粉虱空间分布型更具说服力;并利用空间格局参数确定了理论抽样数和序贯抽样模型。

Two regression models(Iwao’s regression and Taylor’s power principle)and eight aggregation indices[K,C,C A,I,M*,m*/m,L*,L*/(1+m)]were used to test the spatial distribution patterns of B.tabaci populations.The results indicated that the distribution patterns of B.tabaci populations accorded with minus binomial distribution,belonging to a type of aggregated distribution except in August when it was in uniform distribution.The mean aggregation index(λ)suggested that aggregation was caused by environmental factors.In addition,the aggregation indexes(K,C A,m*/m)could better explain the spatial distribution patterns of B.tabaci populations.The theoretical sampling number and sequential sampling model were inferred from the spatial pattern parameters.