黑点切叶野螟幼虫在空心莲子草上空间分布与抽样技术研究

Spatial Distribution Pattern and Sampling Technique of Larvae of Herpetogrammabasalis(Walker) on Alternanthera philoxeroides

在黑点切叶野螟[Herpetogramma basalis(Walker)]幼虫盛期,应用扩散系数C、扩散型指数Iδ、负二项分布K值、CA指标、聚集度指标I、平均拥挤度(m*)和平均密度(X)的比值m*/X、Taylor幂法则及Iwao的m*-X回归分析法等8个聚集度指标,对黑点切叶野螟幼虫在空心莲子草[Alternanthera philoxeroides(Mart.)Grisb]样田的空间格局进行研究。结果表明,黑点切叶野螟幼虫在空心莲子草样田内呈聚集分布。在空间格局的基础上提出了理论最适抽样数和复合序贯抽样方案的计算模型,提高了田间调查效率。

The spatial distribution pattern of larvae of Herpetogramma basalis(Walker)in Alternanthera philoxeroides field was studied by Iwao method,Taylor method models and eight indices of aggregation(C,Iδ,K,CA,I,m*/X).The indices indicated that the larvae of H.basalis belonged to the pattern of aggregation distribution.A sampling mode with theoretical optimum sampling number and the compound sequential sampling method was presented on the base of the spatial distribution pattern to improve survey efficiency.