樟子松梢斑螟幼虫空间分布型研究

为了研究樟子松梢斑螟(Dioryctria mongolicella)幼虫在樟子松栽植区的空间分布格局和抽样技术,并为该虫的野外调查与防治提供理论依据,采用8个聚集度指标和3种回归分析法对樟子松梢斑螟幼虫的空间分布型进行测定。同时,通过Iwao回归法计算了樟子松梢斑螟幼虫种群的最适抽样量并拟合序贯抽样模型。结果表明,樟子松梢斑螟的8个聚集度指标均显示为聚集分布,分布的基本成分是种群,且个体之间相互吸引。随着田间平均虫口密度的增大,抽样数逐渐减少;随着允许误差逐渐减小,所需要的抽样数就越大。建立的序贯抽样表和最适抽样量表可在林间调查中应用。

Spatial Distribution Pattern of Dioryctria mongolicella Larvae

In order to study the spatial distribution pattern&sampling technique of Dioryctria mongolicella larvae in the planting area of Pinus sylvestris var.mongolica,and provide the theoretical basis for field investigation&control of this pest,eight aggregation indexes and three regression analysis methods were used to determine the larval spatial distribution pattern of it.Meanwhile,Iwao regression method was used to calculate the optimal sampling amount and fit sequential sampling model for larvae population of D.mongolicella.Result shows that all the eight aggregation indexes showed aggregation distribution of D.mongolicella larvae,and the basic component of distribution was population,and the individuals attracted each other.The aggregation meanλ<2 indicated that the aggregation distribution of larvae was mainly caused by environmental factors.The model of optimum sampling quantity shows that the number of samples decreases with the increase of the average insect population density in the field.As the allowable error decreases,the number of samples required increased.The sequential sampling&optimum sampling scale table which were established in this study could be used in the field investigation,The result of this study establish a basis for the field sampling and precise control of D.mongolicella.