Development of a numerical simulation model for long-range migration of rice planthoppers

Furuno, Akiko   ; Chino, Masamichi; Otsuka, Akira*; Watanabe, Tomonari*; Matsumura, Masaya*; Suzuki, Yoshito*

Transoceanic migration of rice planthoppers was precisely simulated by incorporating several parameters related to the flight behavior with a high performance atmospheric dispersion model. The model consists of an atmospheric dynamic submodel and a particle random-walk submodel for atmospheric dispersion. The model also functions in specifying the release area of the migration of planthoppers. Using this model, we carried out a case study simulating the migration of planthoppers to western Japan in mid-June 1998. In the simulation, 56 areas each with a width of two degrees of latitude and longitude were set as tentative take-off areas. The calculated density of immigrants was compared with each observed density by rank correlation coefficients. Possible migration release areas which showed a high correlation to observations were distributed around 23-27N, including Fujian and Taiwan. An air temperature that allowed the planthoppers to fly continuously and flight duration were critical parameters for the simulation results.