伊犁河谷玉米田草地贪夜蛾发生风险定量评估

Quantitative Assessment of Fall Armyworm (Spodoptera frugiperda) Establishment Risk in Maize Fields of the Yili River Valley

摘要: 草地贪夜蛾(Spodoptera frugiperda (J. E. Smith))是联合国粮农组织全球预警的重大迁飞性害虫，自2019年入侵我国后已扩散至西北边境，对新疆玉米生产构成潜在威胁。为明确其在伊犁河谷的发生风险，本研究基于该虫全世代发育起点温度12.6℃、有效积温584.0日·度的生物学参数，结合伊犁河谷9个县(市)多年平均气温、≥10℃活动积温、降水、无霜期及玉米种植面积等数据，采用有效积温法估算理论发生世代数，并构建涵盖传入、定殖和为害3个环节共7项指标的多指标综合风险评价模型，结合层次分析法确定指标权重，对各县(市)发生风险进行定量分级。结果表明：伊犁河谷各县(市)草地贪夜蛾理论发生世代数为0.62~2.99代，河谷平原区可完成2.7~3.0代；综合风险值为1.10~2.64，伊宁县、察布查尔锡伯自治县、伊宁市和霍城县为高风险区，新源县、巩留县和尼勒克县为中风险区，特克斯县和昭苏县为低风险区。伊犁河谷冬季严寒，该虫不能在当地稳定越冬，风险主要来自夏季随偏南暖湿气流的逐代北迁和口岸农产品调运传入，区域气候暖湿化趋势将进一步抬升其入侵与定殖风险。据此提出分区监测预警、检疫阻截和应急防控对策，可为伊犁乃至中亚干旱半干旱地区草地贪夜蛾的早期预警和科学防控提供依据。

Abstract: The fall armyworm, Spodoptera frugiperda (J. E. Smith), is a major migratory pest under global alert by the Food and Agriculture Organization of the United Nations. Since its invasion of China in 2019, it has spread to the northwestern border regions, posing a potential threat to maize production in Xinjiang. To elucidate its occurrence risk in the Yili River Valley, this study integrated the species’ biological parameters, specifically, a whole-generation developmental threshold temperature of 12.6˚C and an effective accumulated temperature of 584.0 degree-days, with multi-year climatological data (mean annual temperature, ≥10˚C accumulated temperature, precipitation, frost-free period) and maize planting area from nine counties (cities) in the valley. The theoretical number of annual generations was estimated using the effective accumulated temperature method. A multi-criteria comprehensive risk assessment model encompassing seven indicators across three key processes (introduction, establishment, and impact) was constructed, with indicator weights determined through the Analytic Hierarchy Process (AHP), to quantitatively classify the occurrence risk in each county (city). Results indicated that the theoretical number of generations ranged from 0.62 to 2.99 across each county (city) in the Yili River Valley, with the valley plain areas capable of supporting 2.7 to 3.0 generations annually. The comprehensive risk values ranged from 1.10 to 2.64, identifying Yining County, Qapqal Xibe Autonomous County, Yining City, and Huocheng County as high-risk areas; Xinyuan County, Gongliu County, and Nilka County as medium-risk areas; and Tekes County and Zhaosu County as low-risk areas. Given the severe winter cold in the Yili River Valley, S. frugiperda cannot stably overwinter locally; the primary risks stem from successive northward migration driven by warm, moist southerly air currents during summer and introduction through agricultural product transport at border ports. The regional trend toward warmer and wetter climatic conditions is expected to further elevate its invasion and establishment risk. Accordingly, this study proposes zonal strategies for monitoring and early warning, quarantine interception, and emergency control, which can provide a scientific basis for early warning and rational management of S. frugiperda in the Yili River Valley and similar arid and semi-arid regions across Central Asia.