食芽象甲成虫在陕北枣园的空间分布格局

Spatial distribution of Scythropus yasumatsui K8no et Morimoto adults in jujube orchard of Northern Shaanxi

为有效防控食芽象甲Scythropus yasumatsui K8no et Morimoto在陕西榆林地区枣园的危害,在田间调查的基础上,使用Iwao回归分析法、Taylor幂法则和5种常用指标参数,探明了成虫在不同枣园样地中的分布格局、理论抽样数及成虫的序贯抽样方法。食芽象甲成虫在枣树上的空间格局为聚集型,个体间相互吸引,其聚集性随密度的增大而增加。对成虫进行序贯抽样,当每株成虫达到30头,置信水平为1.96时,序贯抽样进行抽样的防治下限与上限方程分别为:d_0=30n-34.33n^(1/2)和d1=30n+34.33 n^(1/2),当调查10株枣树上的虫数超过409头时,需要进行防治。食芽象甲成虫空间分布型及抽样方法的确定,对于揭示该虫的种群空间结构动态,提高田间测报准确率及防治效果都具有十分重要的意义。

To effectively control the damage caused by Scythropus yasumatsui K8 no et Morimoto in jujube orchards of Yulin,Shaanxi Province,the spatial distribution pattern,sequential sampling and theoretical sampling number of adults in different plots were analyzed by using Iwao's regression analysis,Taylor's power law and five aggregation indices through field investigation.The adults were of aggregative distribution pattern in jujube trees with an individual fundamental component,and their aggregation increased as the population density of adults grew.Below the control threshold of adults with30 individual/plant and the confidence level with1.96,the lower limit and upper limit formula of sequential sampling was d_0=30 n-34.33 n^(1/2) and d_1=30 n+34.33 n^(1/2),respectively.Measures needed to be taken if the amount of adults was over 409 in10 jujube trees.The spatial distribution and sampling technique of adults could have significant implications for clearing the weevil's space structure and improving the prediction and prevention effects.