Abstract:

【Objective】 This thesis aims to determine the spatial distribution characteristics of Codling Moth in walnut orchards in the hope of providing a scientific basis for field surveys, forecasting, and effective control measures.【Methods】 Methods employed included traditional statistical approaches (six aggregation indices, Taylor's power law, and Iwao's regression model) and geostatistical methods to study the spatial distribution patterns of adult moths and larvae in walnut orchards.Theoretical sampling numbers for adult moths and larvae were established based on Iwao's regression model.【Results】 The spatial distribution of adult Codling Moth populations in walnut orchards was aggregated.Both adult and larval distributions were of an aggregated type.The aggregation of both adult and larval populations increased with population density, illustrating an aggregated distribution.Iwao's regression model confirmed that the spatial distribution type belonged to an aggregated distribution, specifically fitting a negative binomial distribution.The best fit models for Codling Moth populations were spherical, exponential, and linear, demonstrating an aggregated spatial pattern.Kriging interpolation analysis provided three-dimensional and two-dimensional spatial distribution maps of adult and larval populations, with aggregation centers primarily located at the edges of the fields.Using Iwao's regression model for sampling technology, the theoretical sampling numbers for adult moths at confidence probability t=2 and varying average densities m=3, 5, 7, 10, 15, 20, 25 and 30 were established.Sequential sampling was conducted to determine the maximum theoretical sampling numbers; at t=2 with D=0.05, 0.10, 0.20 and 0.30, the maximum theoretical sampling numbers for an average density of m₀=3 moths per trap were 3,432, 348, 88 and 92 respectively; for larval stages at confidence probability t=2 and average densities m=1, 2, 3, 4, 5, 6, 7, 8, 9 and 10, the theoretical sampling numbers were determined.Sequential sampling established the maximum theoretical sampling numbers; at t=2 with D=0.05, 0.10, 0.20 and 0.30, the maximum theoretical sampling numbers for an average density of m₀=1 larva per hundred fruits were 1,738, 435, 109 and 48 respectively.【Conclusion】 The spatial distribution patterns of both adult and larval Codling Moth populations are negatively binomially distributed with aggregation centers located mainly at field edges.The theoretical maximum sampling numbers determined by sequential sampling are essential for guiding monitoring and control efforts in walnut orchards.

Key words: Cydia pomonella L.; spatial distribution patterns; aggregation indices; sampling techniques; geostatistics

摘要：

【目的】研究苹果蠹蛾成虫以及幼虫的田间空间分布型,分析其在核桃园的空间分布特征,为苹果蠹蛾的田间调查、预测预报以及有效防治提供科学依据。【方法】应用传统统计学(6种聚集度指标、Taylor幂法则以及Iwao的回归模型)以及地统计学方法研究核桃园苹果蠹蛾成虫、幼虫的空间分布型,基于Iwao 回归模型确定苹果蠹蛾成虫及幼虫的理论抽样数。【结果】苹果蠹蛾成虫种群在核桃园的空间分布型均属于聚集分布。苹果蠹蛾成虫、幼虫的分布型均为聚集型;苹果蠹蛾成虫、幼虫种群为聚集分布,且聚集强度随种群密度的升高而增加;Iwao 回归模型证明苹果蠹蛾的空间分布型属于聚集分布,且为一般的负二项分布。苹果蠹蛾种群的最优拟合模型为球型、指数型和线型,空间分布型为聚集型;苹果蠹蛾成虫及幼虫种群的三维和二维空间分布聚集中心主要分布在田块边缘。苹果蠹蛾成虫在置信概率 t=2,成虫不同平均密度 m=3、5、7、10、15、20、25和30时的理论抽样数。进行序贯抽样确定了最大理论抽样数,在 t =2, D=0.05、0.10、0.20和0.30 时,当 m₀ =3头/诱捕器,最大理论抽样数分别为 3 432、348、 88 和92;苹果蠹蛾幼虫在置信概率 t =2,成虫不同平均密度 m =1、2、3、4、5、6、7、8、9和10时的理论抽样数。序贯抽样确定了最大理论抽样数,在 t =2, D =0.05、0.10、0.20和0.30 时,当 m₀ =1头/百果,最大理论抽样数分别为 1 738、435、 109 和48。【结论】苹果蠹蛾成虫及幼虫种群的空间分布型为聚集分布中的负二项分布,聚集中心主要分布在田块边缘。最大抽样数可用于指导核桃园苹果蠹蛾的监测和防治。

关键词: 苹果蠹蛾, 空间分布型, 聚集度指标, 抽样技术, 地统计学