玉米田草地贪夜蛾幼虫的空间分布型与抽样技术

草地贪夜蛾Spodoptera frugiperda(J. E. Smith)是一种世界性的重大农业害虫,已于2019年1月侵入中国云南省西部地区,对当地主要经济作物鲜食玉米的生产构成了严重威胁。我们调查了入侵成虫后代幼虫在鲜食玉米田的种群密度和为害情况,分析了幼虫种群的空间分布格局。结果表明,草地贪夜蛾幼虫在玉米田呈聚集分布,聚集度随密度的增加而升高,环境是导致聚集分布的主要因素。基于空间分布型的分析结果,进一步研究提出了幼虫密度的理论抽样模型和基于幼虫密度防治指标的序贯抽样技术。本研究明确了草地贪夜蛾幼虫在玉米田的空间分布特征和抽样方法,为通过调查田间种群密度指导幼虫防治工作提供了技术支撑。

Larval spatial distribution pattern and sampling technique of the fall armyworm Spodoptera frugiperda in maize fields

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a major agricultural pest worldwide. It invaded the western part of Yunnan Province in January 2019 and poses a serious threat to the production of fresh-eating maize, the main cash crop in Yunnan Province. We investigated the larval population density from invasive adults and its damage in fresh-eating maize fields, and analyzed the spatial distribution pattern of larval populations. The results showed that the larvae exhibited a pattern of aggregation distribution in the maize field, and the aggregation degree increased with increasing larval density. The environment was the main factor leading to the aggregation distribution. Based on the results of spatial distribution analysis, a theoretical sampling model of larval density and a sequential sampling technique in connection with larval control threshold were proposed, which provided a technical support for guiding larval control by investigating population density in the field.