柠条绿虎天牛幼虫空间分布型及抽样技术

[目的]研究柠条锦鸡儿上的一种重要蛀干害虫柠条绿虎天牛(Chlorophorus caragana Xie & Wang)幼虫空间分布型及抽样技术,揭示其幼虫的行为、习性、活动规律以及确定其在林间的适宜抽样调查方法.[方法]应用分布型指数法和回归模型法,对幼虫的空间分布型进行了研究.[结果]柠条绿虎天牛幼虫的空间分布型属于聚集分布,种群分布的基本成分为个体群.根据Iwao (*m)-m关系的序贯抽样决策模型确定了幼虫的序贯抽样模型公式及最大理论抽样公式,建立了精度分别为0.1和0.2时的理论抽样数表,为野外抽样调查、密度估计及预测预报提供了依据.在幼虫为1、2、3头/株时,累计虫口数的上下限分别为536和134、281和70、197和49.[结论]所建立的理论抽样公式可在天牛幼虫调查、预测预报和防治中推广应用,对生产防治指标的制定及综合防治具有重要意义.

Spatial distribution pattern and sampling techniques of the Chlorophorus caragana larvae

[Objective] Chlorophorus caragana Xie & Wang is a serious boring pest of the Caragana spp.,and its larvae primarily cause damage to roots and branches of Caragana korshinskii.This study was conducted to understand the spatial distribution pattern and sampling techniques of the larvae.[Method] Spatial distribution of the larvae was investigated by aggregation index examination and regression analysis.[Result] The results indicated that the larvae had an aggregated spatial pattern and the basic component of distribution was individual group.Sequential sampling formulas and the maximum theoretical sampling number could be calculated by the Iwao’s m*-m,which gave the estimated sample size for different population densities of larvae with an accuracy of 0.1 and 0.2,respectively.It can provide the basis for field sampling,density estimation and pest forecast.The upper limit and lower limit of accumulated larvae for sequential sampling were 536 and 134,281 and 70,197 and 49 at 1,2 and 3 larvae per tree,respectively.[Conclusion] The model can be used in survey,forecast and control of the pest.