Fig. 1.

Map of the study area in East Asia. The Korean Peninsula and islands of Japan as well as east China were parts of many animals’ migration pathways in eastern Asia. Caterpillars of S. frugiperda were found in southern Korea and southwestern Japan in June and July 2019 (A, B and C). Their sites are shown in circled points; among these sites, bigger solid circles in (D) have been analyzed in detail. These caterpillars were also distributed in southern and eastern China, such as Anhui, Fujian, Zhejiang, Jiangxi, Guangdong and Taiwan Provinces. Chinese sites of S. frugiperda’s larvae found are shown in solid triangles (D). The possible arrival date of FAW moths at each site in Korea and Japan, and the emergence date of FAW moths at each site in China were estimated based on day‐degree model. GS(2021)3135.