Strontium isotope and trajectory method elucidating overseas migration of Mythimna separata to Japan
Naoya Hidaka,
Caihong Tian,
Shengnan Zhang,
Gaku Akiduki,
Guoping Li,
Ichiro Tayasu,
Ki-Cheol Shin,
Tokumitsu Niiyama,
Gao Hu,
Shimin Li,
Akira Otuka,
Hongqiang Feng
Affiliations
Naoya Hidaka
Institute for Plant Protection, National Agriculture and Food Research Organization, Koshi, Kumamoto 861-1192, Japan
Caihong Tian
International Joint Research Laboratory for Crop Protection of Henan, Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou, Henan 450002, P.R. China
Shengnan Zhang
International Joint Research Laboratory for Crop Protection of Henan, Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou, Henan 450002, P.R. China
Gaku Akiduki
Institute for Plant Protection, National Agriculture and Food Research Organization, Koshi, Kumamoto 861-1192, Japan
Guoping Li
International Joint Research Laboratory for Crop Protection of Henan, Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou, Henan 450002, P.R. China
Ichiro Tayasu
Research Institute for Humanity and Nature, Kyoto 603-8047, Japan
Ki-Cheol Shin
Research Institute for Humanity and Nature, Kyoto 603-8047, Japan
Tokumitsu Niiyama
Akita Plant Protection Station, Akita 010-1231, Japan
Gao Hu
College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu 210095, P.R. China
Shimin Li
Institute of Plant Protection, Luohe Academy of Agricultural Sciences, Luohe, Henan 462300, P.R. China
Akira Otuka
Institute for Plant Protection, National Agriculture and Food Research Organization, Koshi, Kumamoto 861-1192, Japan; Corresponding author
Hongqiang Feng
International Joint Research Laboratory for Crop Protection of Henan, Institute of Plant Protection, Henan Academy of Agricultural Sciences, Zhengzhou, Henan 450002, P.R. China; Corresponding author
Summary: The oriental armyworm, Mythimna separata, generally migrates from eastern to northeastern China in early summer, and some individuals are believed to migrate overseas to Japan depending on meteorological conditions. This potential migration was investigated with the immigrants’ strontium radiogenic isotope ratio 87Sr/86Sr and backward flight trajectories from Japanese trapping sites. The results showed that the 87Sr/86Sr ratios of Chinese reared M. separata were significantly higher than those of reared insects of Japanese immigration areas. As some individuals trapped in western Japan had 87Sr/86Sr ratios higher than a statistical discriminating ratio, they likely originated in China. Trajectory analysis also indicated those individuals might have originated from the East Asian continent, such as the first-generation outbreak region in China and their migration waypoint regions. Our analysis, thus, suggests direct or multistep overseas migration of individual M. separata from the East Asian continent to Japan, giving insight into migration pathways and population dynamics.
