. Army worm migrates horizontally and vertically in an annual period in the zones covering the planis of eastern China and the Plateaus of western China. From winter solstice to summer solstice, from latitudes 19°N to 53°N, it migrates from south to north, from 10m above sea level upwards to 2,500m; after this period it does vice versa, namely, it remigrates from north to south and from high level downwards, whenever it migrates to a new zone, it reproduces a new generation, the cycle of each generation, w...