经测定稻粉虱幼虫和蛹在田间的分布型为核心分布 ,分布的基本成分是个体群。个体群分布随着种群密度的提高而渐趋向于随机分布。经种群聚集均数 (λ)测定 ,其聚集原因是由于稻粉虱自身的聚集性所引起 ,λ随平均密度 ( X)的增加而呈直线增加。采用Iwao的抽样模式 ,大田调查当种群密度较低时 (株平均虫量 <5头 ) ,可抽样 5 0～ 10 0株 ;株平均虫量 >5头时 ,取样 15～ 30株。 The distribution of rice whitefly larvae and pupae in the field was determined as the core distribution. The basic components of the distribution were individual groups. Individual population distribution tends to be random distribution with population density increasing. The results of population aggregation (λ) showed that the aggregation was caused by its own aggregation, and λ increased linearly with the increase of average density (X). When using Iwao sampling method, when the population density is low (average number of worms per plant is less than 5), 5 0-10 0 can be sampled; when the average number of pests is 5, 15-30 plants are sampled.