烟盲蝽及其天敌蜘蛛空间格局的地统计学分析

Geostatistical analysis of spatial patterns of Nesidiocoris tenuis(Reuter)(Hemiptera:Miridae) and its natural enemy spiders

利用地统计学的方法研究了烟草(品种为中烟100)不同生长期烟盲蝽及天敌蜘蛛的空间格局,结果表明:烟盲蝽的空间格局随时间的变化呈现为随机、聚集、再随机和再聚集;尽管蜘蛛混合种群的空间格局也依次表现为随机、聚集、随机和聚集分布,但只是在后期与烟盲蝽的空间格局一致。利用BlockKriging进行空间插值分析,得到的三维空间插值模拟图能很好地反映烟盲蝽和蜘蛛种群的田间分布状况。同时,对烟盲蝽及天敌蜘蛛的种群动态进行了分析,发现它们的种群数量变化趋势相似。所有结果表明蜘蛛种群在较大程度上与烟盲蝽种群存在跟随关系。

Green tobacco capsid,Nesidiocoris tenuis,is one of the important insect pests on tobacco.It pierces and sucks on the leaves,growing points and buds,which can not only result in pale spots and slow growth,but also transmit some virus diseases.As very important biological agent,spiders such as Hylyphantes graminicola,Misumenops tricuspidatus and Coleosoma octomaculatum can have good control efficiency on the insect pest in tobacco field.This research was carried out to reveal the spatial patterns and population dynamics of the insect pest and spiders in different growing stages of tobacco（Zhongyan-100） at the Experimental Station of Shandong Agricultural University,and aim to lay the theoretical foundation for sampling and management of the pest and conservation of spiders.N.tenuis immigrated into tobacco field gradually from the surroundings during transplanting and rosette stages of tobacco,and its population showed random distribution.The semivariograms of N.tenuis were fitted by the exponential,spherical and linear models with the ranges of 6.92-65.56m in vigorous growth stage of tobacco,and the spatial pattern belonged to aggregative distribution.The population of N.tenuis distributed randomly again after the vigorous growth stage.When the habitat was steady gradually after the first harvest,the semivariograms of the pest were fitted by exponential and spherical models with the ranges of 31.11-58.84m,and the spatial pattern obviously displayed aggregative distribution with the aggregative intensities above 65%.Therefore,the spatial patterns of N.tenuis showed random,aggregative,random and aggregative patterns in the temporal sequence,respectively.In comparison with that of N.tenuis,the spatial pattern of spiders was random distribution with the small population of N.tenuis at the early stage and became aggregative with the rising number of N.tenuis.Affected by the spatial patterns of N.tenuis in the late growing period,the spatial pattern of spiders took on random distribution in a short time,and then turned into aggregative distribution.So the spatial patterns of spiders also showed random,aggregative,random and aggregative patterns in the growing period,respectively.Although the spiders displayed the similar spatial patterns to that of N.tenuis,they only coincided with N.tenuis in the aggregative spatial pattern in the later growing period,especially the ranges of spiders（3.42-64.09m） were highly similar to that of N.tenuis（6.92-58.84m）.The simulated 3D-maps of spatial distribution obtained from the analysis of Block Kriging interpolation can intuitively show the spatial distributions of N.tenuis and spiders in the field.Meanwhile,the temporal dynamics of N.tenuis and spiders populations was analyzed.The population density of N.tenuis increased slowly at the rosette stage,rose quickly in the early and middle parts of vigorous growth stage and peaked at the ripe stage,thereafter the density decreased gradually with the aging tobacco plants.The population dynamics of spiders was similar to that of N.tenuis.All the results in this studies indicated that the spiders had a good synchronization with the occurrence of of N.tenuis in the tobacco field.