A migration analysis for rice planthoppers, Sogatella furcifera (Horvath) and Nilaparvata lugens (Stal) (Homoptera: Delphacidae), emigrating from northern Vietnam from April to May

Rice planthoppers are long-distance migratory insects. The East Asian population is believed to migrate from northern Vietnam to southern China in the spring. To understand its major migration paths, a migration analysis was conducted with catch data by a single light trap located in the Red River delta in northern Vietnam. The catch data showed large peaks in late April to early May, each of which was used as a starting point of a simulation. Destination regions of simulated migrations were found to be distributed over southern Chinese provinces: Guangxi, southern Hunan, Jiangxi, northern Guangdong and northwestern Fujian. The region formed a diagonal belt stretching in the northeast direction. According to Chinese data, many planthoppers were caught in light traps along the diagonal belt region, supporting the simulation results. The planthoppers that arrive on rice plants of the early crop can multiply by one or two generations before their next emigration.