4.Life Cycle 2)White backed planthopper 冬 Migratory pest,no diapause. *Northern boundary limit is about 12'C isotherm (26N.)in January. *1-11 generations annually in different paddy planting areas;11 in Southern Hainan;1~2 in Xinjiang,Ningxia.2) White backed 2) White backed planthopper planthopper ™ Migratory pest, no Migratory pest, no diapause diapause. ™ Northern boundary limit is about 12 Northern boundary limit is about 12℃ isotherm (26 isotherm (26o N.) in January. N.) in January. ™ 1-11 generations annually in different 11 generations annually in different paddy planting areas; 11 in Southern paddy planting areas; 11 in Southern Hainan; l~2 in Xinjiang, Ningxia. Hainan; l~2 in Xinjiang, Ningxia. 4. Life Cycle 4. Life Cycle