4.Life Cycle 1)Brown planthopper 冬 Migratory pest,no diapause. 水 Northern boundary limit is about 12'C isotherm (230-26 N.)in January. *1-12 generations annually in different paddy planting areas;12 in southern Hainan;1~2 just north of 35 N
1) Brown 1) Brown planthopper planthopper Migratory pest, no Migratory pest, no diapause diapause. Northern boundary limit is about 12 Northern boundary limit is about 12℃ isotherm (23 isotherm (23o-26o N.) in January. N.) in January. 1-12 generations annually in different 12 generations annually in different paddy planting areas; 12 in southern paddy planting areas; 12 in southern Hainan; l~2 just north of 35 Hainan; l~2 just north of 35o N. 4. Life Cycle 4. Life Cycle
4.Life Cycle 1)Brown planthopper *Every year this insect comes from the southern end of the Asian continent to China. During spring and summer,has 5 migrations from southern to northern China on warm and moist airflow currents
1) Brown 1) Brown planthopper planthopper Every year this insect comes from the Every year this insect comes from the southern end of the Asian continent to China. southern end of the Asian continent to China. During spring and summer, has 5 During spring and summer, has 5 migrations from southern to northern China migrations from southern to northern China on warm and moist airflow currents. on warm and moist airflow currents. 4. Life Cycle 4. Life Cycle
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
4.Life Cycle 1)Small brown planthopper Overwinter as 3rd or 4th nymphs in fields of wheat,green-manure or weeds growing in near channels and rivers. *4-8 generations annually in different paddy planting areas;4-5 in northern China
1) Small brown 1) Small brown planthopper planthopper Overwinter Overwinter as 3rd or 4th nymphs in fields nymphs in fields of wheat, green of wheat, green-manure or weeds growing manure or weeds growing in near channels and rivers. in near channels and rivers. 4-8 generations annually in different 8 generations annually in different paddy planting areas; 4 paddy planting areas; 4-5 in northern 5 in northern China. 4. Life Cycle 4. Life Cycle
4.Behavior 1)Bio-types Short wing type:high productive ability; weak migratory; Long wing type:low productive ability; strong migratory;
1) Bio-types Short wing type: high productive ability; weak migratory; Long wing type: low productive ability; strong migratory; 4. Behavior 4. Behavior