青海云杉一种重要害虫烟翅腮扁蜂越冬幼虫的空间分布型与抽样技术

Spatial Distribution Patterns and Sampling Techniques of Overwintering Larvae of Cephalcia infumata-An Important Pest in Picea crassifolia

为研究烟翅腮扁蜂(Cephalcia infumata)越冬幼虫在地下的空间分布,采用聚集度指标法、Taylor幂法则和Iwao回归法对烟翅腮扁蜂越冬幼虫的空间分布型进行分析。基于Iwao回归模型确定烟翅腮扁蜂越冬幼虫的理论数,通过序贯抽样技术得到不同允许误差(D=0.1、0.2、0.3)和经济阈值(m_0=3、5、10头/株)下的最大理论抽样数。结果表明,在宁夏罗山国家级自然保护区内,烟翅腮扁蜂1年发生1代,越冬幼虫主要分布在0~10 cm土壤中,在阳坡发生量大,呈聚集分布,符合负二项分布,种群聚集均数与种群平均密度呈线性关系,聚集程度随种群密度增大而增强。基于I_(wao)回归模型,在t=1.96时,当m_0=3头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为596、149、66株;当m_0=5头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为477、119、53株;当m_0=10头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为388、97、43株。烟翅腮扁蜂的种群空间分布型为聚集分布,主要发生在林缘。基于序贯抽样确定的最大抽样数可用于指导烟翅腮扁蜂的监测和防治。

This study investigates the spatial distribution of the overwintering larvae of Cephalcia infumata in the soil to provide a scientific basis for its prediction and control.The spatial distribution pattern of the overwintering larvae was analyzed by using aggregation index method,Taylor’s power law and Iwao’s regression method.The theoretical number of overwintering larvae was determined based on the Iwao regression model,and the maximum theoretical sampling numbers under different permissible errors(D=0.1,0.2,0.3)and economic thresholds(=3,5,10 individuals/plant)were obtained through sequential sampling techniques.The results show that in the forest area of the Ningxia Luoshan Nature Reserve,Cephalcia infumata produces one generation per year,with overwintering larvae mainly distributed in the soil at depths of 0~10 cm.The larvae are more abundant on sunny slopes and show an aggregated distribution that fits the negative binomial distribution.The mean aggregation of the population shows a linear relationship with the average population density,and the intensity of aggregation increases with population density.Based on the Iwao regression model,at t=1.96,the maximum theoretical sampling numbers were 596,149 and 66 plants for=3 and D=0.1,0.2,and 0.3,respectively;477,119 and 53 plants for=5 and D=0.1,0.2,and 0.3,respectively;and 388,97,and 43 plants for=10 and D=0.1,0.2,and 0.3,respectively.The spatial distribution pattern of Cephalcia infumata was aggregated,mainly occurring at the forest edge.The maximum sampling number determined by sequential sampling can be used to guide the monitoring and control of Cephalcia infumata.