玉米马铃薯间作对小绿叶蝉种群时空动态格局的影响

Study on Temporal-spatial Dynamics of Empoasca flaoescens in Maize-potato Intercropping

桃小绿叶蝉Empoasca flaoescens(Fab.)隶属同翅目叶蝉科,是马铃薯植株上的重要害虫之一,为明确玉米//马铃薯种植对马铃薯小绿叶蝉时空格局的影响,于2012—2013年设置田间小区试验,采用五点取样进行田间扫网调查,运用方差分析和聚集度指数综合对比分析。结果表明:本研究调查期内,小绿叶蝉种群数量呈双峰型变化,间作田马铃薯上小绿叶蝉种群密度和种群数量变动幅度均显著低于马铃薯单作田;单作和间作田内马铃薯小绿叶蝉以聚集分布为主,但单作田聚集强度高于间作田;小绿叶蝉种群空间分布为依赖于密度的聚集分布,且不同种群密度下小绿叶蝉的聚集原因有所差异。由此,玉米//马铃薯种植可降低小绿叶蝉田间种群密度,从而改变害虫种群聚集强度和空间分布格局。

Empoasca flaoescens （Fab.）, which belongs to Cicadellidae Homoptera, is one of important potato pests. In order to study the effect of maize-potato intercropping on the temporal dynamics and spatial patterns of E. flaoescens, we set sweep trap every potato growing season from 2012 to 2013 in Daheqiao farm locating in Xundian, Yunnan Province. In this study, ANOVA was used to compare the differences of E. flaoescens abundance and dynamic between two years and two cropping systems, respectively. Five space distribution indexes, Taylor＇s exponential function and Blackith＇s index were used to analyze the spatial patterns of E. flaoescens. The results showed ： （1） There were two population peaks every year in pop- ulations dynamics of E. flaoescens. While, there＇s no significant difference in pop-ations dynamics between two sampling years, but the abundances in potato fields were significant higher than in maize-potato intercropping fields. （2） According to the comprehensive analysis of five space distribution indexes, the spatial patterns of E. flaoescens both in potato monocmpping and intercropping fields are aggregation type, however, the aggregation times in monocropping fields were more than in intercropping fields. （3） Accord- ing to the analysis of Taylor＇s exponential function and Blackith＇s index, the aggregation time and degree of E. flaoescens both in monocropping and intercropping fields were related to pest population density. Moreo- ver, the reasons for the aggregation distribution of E. flaoescens also depended on the population density. Above all, the intercropping method of maize and potato can reduce the population density of E. flaoescens, and effect the aggregation degree and spatial distribution of the pest insect in farming fields.