2020年邳州市草地贪夜蛾初迁虫源的迁入路径及气象背景

2020年江苏省邳州市于3月31日发现草地贪夜蛾Spodoptera frugiperda成虫，远早于该地区2019年草地贪夜蛾的始见期6月份。为明确该地区草地贪夜蛾种群性质，利用昆虫轨迹分析方法，模拟分析了2020年江苏省邳州市早期发现的草地贪夜蛾的迁飞路径及天气背景场。结果表明：邳州市2019年12月-2020年2月温度低，草地贪夜蛾无法在此地越冬存活，2020年3月31日所诱捕的草地贪夜蛾为外地迁入，其虫源来自广西和广东西部的周年繁殖区；虽然邳州市3月份常年盛行北风和西北风，西南风发生概率低导致草地贪夜蛾迁入邳州市概率较小，但2020年3月底850 hPa的强西南气流为草地贪夜蛾从我国华南地区迁入邳州市提供了条件。本研究结果阐明了在极端条件下草地贪夜蛾从华南地区迁入江苏省的可能性，丰富了江苏省草地贪夜蛾春季早期迁入的理论依据。

Analysis of the source of the fall armyworm Spodoptera frugiperda invading Pizhou for the first time in 2020

The fall armyworm (Spodoptera frugiperda) was found in Pizhou City, Jiangsu Province, on 31 March 2020, well before the first S. frugiperda was found in this region in June 2019. To clarify the nature of the S. frugiperda population in the region, the migration paths and weather background fields of the early found S. frugiperda in Pizhou City, Jiangsu Province in 2020 were simulated using insect trajectory analysis. The moths trapped in Pizhou on 31 March 2020 were migrant insects from the annual breeding areas of Guangxi and western Guangdong, and from 25 March to 31 March 2020 there was a strong southwesterly airflow at 850 hPa, which was conducive to the long-distance migration of the moths to Pizhou. However, the prevailing northerly and northwesterly winds in Pizhou in March were low, with a low probability of southwesterly occurrence and low wind speed, making the migration of the S. frugiperda into Pizhou a low probability event. The results clarified the possibility of the migration of S. frugiperda from South China to Jiangsu Province under extreme conditions, and enriched the theoretical basis of the migration of S. frugiperda in early spring in Jiangsu Province.