2016 Volume 60 Issue 1 Pages 23-31
The common cutworm, Spodoptera litura (Fabricius) has a low tolerance to cold; nevertheless, it migrates to Japan from warmer surroundings every year. To clarify the genetic diversity among divergent areas in Asia, phylogenetic relationships were examined by cytochrome oxidase I (COI) sequencing and genome profiling of extracted DNA from S. litura isolated from four Asian countries and eight domestic areas in Japan. Our results clearly showed genomic differences among individuals isolated from Southeast Asia, especially Thailand and Indonesia, compared with those from the domestic areas in Japan, suggesting that this species has formed indigenous populations among these areas. Moreover, evidence indicates that S. litura does not migrate to Japan directly from areas in Southeast Asia because many samples collected throughout Japan were the same strain, which indicated that the S. litura moths migrated from the Ogasawara islands. The individuals collected from China, Taiwan, and Okinawa shared the same cluster. These results certainly indicate that the adult moths of S. litura indigenous to Southern China and Taiwan migrate to Japan via Okinawa.
