Predicting the potential distribution of the fall armyworm Spodoptera frugiperda (J.E. Smith) under climate change in China

The fall armyworm Spodoptera frugiperda (J.E. Smith) is a severe agricultural pest originating from tropical and subtropical America, and it invaded China in December 2018. In this paper, an optimized MaxEnt model was used to simulate the potential distribution of S. frugiperda under current and future climatic conditions based on the global distribution data for S. frugiperda and the latest version of WorldClim climate data. The results showed that the potential distribution area of S. frugiperda in China was 309.19 million hm2, accounting for 32.23% of the total area of the country. The potential distribution areas were primarily distributed over the range of 88.96°~125.04°E and 18.19°~41.15°N in South China, Central China, East China, eastern Southwest China, and parts of Northwest China. The high-suitability areas were primarily distributed in South China, Central China, East China and eastern parts of Southwest China. Among the environmental factors, bio11 (mean temperature in the coldest quarter) and bio12 (annual precipitation) were the main factors affecting the potential distribution of S. frugiperda. Under different future scenarios, the potential distribution areas of S. frugiperda in China will expand northward by 1.16°~5.34°. The total suitable area for S. frugiperda is expected to increase by 5.85~23.44%. The high-suitability and low-suitability areas will increase by 15.45~61.27% and 10.46~127.39%, respectively. In addition, the medium-suitability areas will decrease between 7.94% and 53.79%. And the unsuitable area will decrease between 3.09% and 17.06%. Some of the medium-suitability areas will change to high-suitability areas. This study clarified the trends in the range, area and grade of the potential distribution area of S. frugiperda in China, and it provides a theoretical basis and practical guidance for the monitoring and control of S. frugiperda.