春小麦蚜虫空间分布型及抽样技术研究

目的]研究春小麦蚜虫种群的空间分布型和田间抽样方法。方法]统计试验地小麦上的蚜虫数量,采用聚集度指标法计算小麦蚜虫的田间分布型,分析聚集的原因,确定田间理论抽样数。结果]小麦蚜虫为聚集分布并呈负二项分布型,小麦蚜虫聚集分布是由本身的习性和环境因素共同作用引起的;小麦蚜虫在田间的理论抽样数和样本方差、允许误差有关;样本方差（S2）愈小,允许误差（d′）愈小,无放回理论抽样数愈多;虫口基数不同,理论抽样数不同;当允许误差设定后,样本方差（S2）越大,理论抽样数越大。结论]该研究为小麦蚜虫的预测预报和田间防治提供了科学依据。

Study on the Spatial Distribution Pattern and Sampling Technique of Spring Wheat Aphid

Objective] The aim was to study the spatial distribution pattern and field sampling method of aphid population on spring wheat. Method]The aphid quantity on wheat in tested field was calculated,the field distribution pattern of wheat aphid was calculated by using aggregation index method,the aggregation reason was analyzed and the field theoretical sampling number was ascertained. Result]The wheat aphid population showed aggregation distribution and negative binomial distribution and such aggregation distribution was induced by interaction of its habit and environmental factors. The field theoretical sampling number of wheat aphid was related to sample variance and permissible error; the less the sample variance (S2) was,the less the permissible error (d') was,the bigger the non-return theoretical sampling number was; when the initial population numbers were different,the theoretical sampling numbers were different; after the permissible error was set,the bigger the sample variance (S2) was,the bigger the theoretical sampling number was. Conclusion]This study supplied scientific basis for prediction and field control of wheat aphid.