灰飞虱在玉米田空间分布格局及抽样技术研究

为了提高监测预报与持续控制水平，应用聚集度指标法测定、Iwao法和Taylor幂法则，研究了浙西北玉米田灰飞虱的空间分布格局和抽样技术。结果表明，灰飞虱在玉米田以聚集分布为主，聚集强度随虫口密度增加而增强。其聚集原因经Blackith种群聚集均数测定，当m<1.8072头/株时，其聚集是由某种环境因素（如气候、生育期、长势等）所引起的；当m≥1.8072头/株时，其聚集是由灰飞虱本身生物学特性与环境因素共同作用引起的，在此基础上提出了理论抽样数和序贯抽样模型。研究结果为田间灰飞虱的准确抽样调查和有效防治提供了科学依据。

The Spatial Distribution Pattern and Sampling Technique of the Small Brown Planthopper, Laodelphax striatellus, in Maize Field

The spatial distribution pattern and sampling technique of the small brown planthopper,Laodelphax striatellus,in maize field in the northwestern of Zhejiang Province were studied by the methods of the aggregated indices method,Iwao method and Taylor power law method,in order to improve the monitoring,prediction and the sustained control system for this pest in maize field.All of three methods showed that： the distribution pattern of L.striatellus was the assemble distribution type,with the assemble distribution index increasing along with their population density.It was tested by Blackith’s method,when m1.8072 insect per plant,their aggregation was caused by some environmental factors,such as climate,the growth period and growth vigor;when m≥1.8072 insect per plant,the gathering was caused by the interaction of their life habit and environment factor.Based on this distribution pattern,the model for determining the optimum theoretical sampling number and the optimum sequential sampling were proposed.These results provided scientific basis for sampling investigating precisely and controlling effectively the field populations of L.striatellus.