利用HYSPLIT模型分析茶园假眼小绿叶蝉迁飞扩散行为

Migration and Dispersion of Empoasca vitis in Tea Plantations Analyzed by HYSPLIT

【目的】明确假眼小绿叶蝉[Empoasca vitis (G?the)]迁飞扩散行为特征,揭示影响其种群迁飞扩散的关键因素。【方法】利用系留气球悬挂诱虫黄板诱捕不同朝向、不同高度假眼小绿叶蝉,通过HYSPLIT-4气流动力模型和气象数据,分析模拟假眼小绿叶蝉迁飞扩散行为。通过田间虫口调查,结合种群密度与扩散系数分析,明确推动假眼小绿叶蝉种群分布转化的驱动因素。【结果】假眼小绿叶蝉最高飞行高度为8 m,2~8 m高度内,随高度增加,假眼小绿叶蝉数量逐步下降。HYSPLIT-4气流动力模型分析结果表明,假眼小绿叶蝉迁飞轨迹只与迁飞时间有关,高度对其迁飞轨迹与直线扩散距离没有影响。此外,HYSPLIT-4气流动力模型分析结果还表明,假眼小绿叶蝉24 h直线迁飞距离为35.70~178.10 km。种群密度与扩散系数分析表明,假眼小绿叶蝉有聚集分布和随机分布两种分布型,迁飞和扩散是导致两种分布型转化的重要因素。【结论】借助气流,假眼小绿叶蝉可以实现区域性的迁飞。在种群密度驱动下,假眼小绿叶蝉种群分布存在聚集分布和随机分布的转化,也促使假眼小绿叶蝉种群发生田间扩散和区域性迁飞。因此,假眼小绿叶蝉的防控应以主要防治区为中心,向外扩展200 km的范围内开展统防统治。

【Objective】Migratory and dispersal behaviors of Empoasca vitis(G?the) at tea plantations were analyzed.【Method】Yellow insect-trapping boards attached to ballons were strategically placed at varying heights and orientations in a tea plantation to catch E.vitis.The HYSPLIT-4 airflow dynamics model and meteorological data were used to analyze and simulate the insect migration and dispersion patterns.Based upon the field survey and the data on the population density and dispersion,factors driving the E.vitis movement were postulated.【Result】The maximum flying altitude of E.vitis was 8 m.The insect population steadily declined from 2 m up to 8 m.The HYSPLIT-4 generated insect movement trajectory indicated that the migration time was the only determinant,not the flying altitude nor dispersal distance.The 24h-migration of the insects ranged 35.70-178.10 km and transformed between aggregated and random distribution patterns that typified the dispersion.【Conclusion】E.vitis migrated from region to region affected by prevailing air currents.The movement transitioned between aggregated and random dispersion in the field and regions.Consequently,effective pest control should be executed in the target area and extended no more than 200 km from the border.