黄杨绢野螟发生特点及幼虫空间分布型研究

目的]分析黄杨绢野螟发生特点及幼虫空间分布型,为防治提供理论依据。方法]对保定市朝阳街两旁的绿篱带小叶黄杨进行调查,记录黄杨绢野螟幼虫的虫口密度,研究该虫的发生与周围环境的关系,并根据所调查的369个样方的虫口密度,采用概率分布型比较X2检验的方法和若干聚集度指标的方法,确定幼虫空间的分布型。结果]3种概率分布型与X2检验比较结果表明,3种分布型均有差别,但Possion分布X2检验值与X20.05差别最大,故黄杨绢野螟幼虫极不符合Poission分布 负二型分布差别最小,比较符合负二项分布。各种聚集度指标的计算结果表明,黄杨绢野螟幼虫呈聚集分布。结论]黄杨绢野螟幼虫空间分布型与环境有着直接的关系,同时提出了对该幼虫的防治建议。

Study on Occurrence Characteristics of Diaphania perspectalis and Spatial Distribution of Its Larva

Objective] The aim was to analyze the occurrence characteristics of Diaphania perspectalis and spatial distribution of its larva and then provide the theoretical basis for its control.Method] Through investigating the hedge Buxus sinica in Chaoyang Street of Baoding City and recording the population density of D.perspectalis larva,the relationship between the occurrence of the insect and the surrounding environment was studied.According to the population density of 369 investigated samples,the spatial distribution of its larva was determined by the methods of probability distribution patterns compared with X2 test and some aggregation indexes.Result] The result of 3 kinds of probability distribution patterns compared with X2 test showed that the 3 kinds of probability distribution patterns all had difference,but the difference between the Possion distribution-X2 test value and X20.05 was largest,so D.perspectalis larva did not fit Possion distribution.The difference of the negative binomial distribution was least,so it was more according to negative binomial distribution.The calculation result of each kind of aggregation index showed that D.perspectalis larva presented aggregating distribution.Conclusion] The spatial distribution of D.perspectalis larva had direct relation with environment and meantime the control suggestions on the larva were put forward.