香梨优斑螟在库尔勒香梨园中的空间分布

Distribution pattern of Euzophera pyriella Yang in the garden of Pyrus sinkiangensis Yü

为调查香梨优斑螟（EuzopherapyriellaYang）在库尔勒香梨树上的危害特点，对所选样地内全部香梨树进行刮皮查虫，利用聚集度指数测定和地统计学方法对香梨优斑螟空间分布情况进行分析。结果表明：在垂直方向上，香梨优斑螟主要集中在距离地面50—100cm范围内；在水平方向上，香梨优斑螟集中分布于距离主干30～90cm的侧枝上。不同聚集度指标表明香梨优斑螟在库尔勒香梨园中呈聚集型分布，且香梨优斑螟最适抽样公式为m=1．4934m＋0．1566（R2=0．9691）；全方向的变异函数曲线图分析得知，所调查4块样地内香梨优斑螟种群的局部空间连续性强度分别为93％、96．3％、67．6％和90．2％，空间依赖距离分别为5．64、6．38、7．79和5．12m，香梨优斑螟在香梨园中分布符合球形模型。

In order to analyze the Euzophera pyriella Yang hazards to Pyrus sinkiangensis Yti, the distribution pattern of E. pyriella Yang in the garden of P. sinkiangensis Yi by using statistical methods of aggregation degree indication and GIS. Results showed that in vertical direction,the main distribution of E. pyriella Yang was above the ground 50 - 100 cm in horizontal direction, the E. pyriella Yang distributed mainly in the lateral branch away 30 -90 cm from the main trunk. The spatial distribution pattern of the E. pyriella Yang was gathering type from aggregation degree indication anal- ysis. According to the Iwao% method, the most suitable sampledate formula was m＊ = 1. 493 4m ＋ 0. 156 6（R2 = 0. 969 1 ） under different population density of E. pyriella Yang. The isotropic variogram analysis indicated that the in- tensity of spatial continuity was 93%, 96.3%, 67.6%, and 90.2%, while the distance of spatial dependence of Euzo- phera pyriella Yang in the four samples was 5.64, 6.38, 7.79 and 5.12 m. The contour map was generated by using Kriging techniques. The theoretical model of spatial distribution pattern was spherical. The theoretical model had changed because of the anthropogenic factors.