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本文采用扩散系数Ｃ法、扩散指数Ｉ０法、Ｃａｓｓｉｃ指标ＣＡ法，种群群集均数入法，Ｔａｙｌｏ指数ｂ法和Ｉｗａｏ的平均拥挤度ｍ与平均数ｘ的回归分析法，测定了杨树上光肩星天牛幼虫的空间分布属于聚集分布，符合负二项分布模型。同时探讨了空间分布型在序贯抽样中的应用。行道树和防护林中理论取样数（Ｎ）与单株虫口平均密度（ｘ－）的关系分别为：Ｎ＝８．００利用有虫株率（Ｐ）简易估计虫口密度的关系式分别为：ｘ＝７．２６２０［－／ｎ（１一Ｐ）］￣０．６００３和ｘ＝３．６９２５［－１ｎ（１－Ｐ）］￣．３９１０１。
In this paper, we used the diffusion coefficient C method, diffusion index I0 method, Cassic index CA method, population clustering method, Taylo index b method and Iwao average crowding degree m and the average number of x regression analysis, The spatial distribution of larvae belongs to the aggregation distribution, in line with the negative binomial distribution model. The application of spatial distribution in sequential sampling is also discussed. The relationship between the theoretical number of samples (N) and the average population density (x-) per plant in street trees and shelterbelts were as follows: N = 8.00 The simple estimates of population density using insect plant strains (P) were as follows: x = 7.2620 [- / n (1-P)] ~ 0.6003 and x = 3.6925 [-1n (1-P)] ~. 39101.