我县晚稻田飞虱主要有白背飞虱和褐稻虱。自1981年以来,田间自然种群数量年度间,各代间变化均很大,据1981—1991年田间系统观测资料统计,,在自然情况下,白背飞虱在杂交稻上第三,四代群体发生数量明显高于常规稻。三代发生量:杂交稻平均为30.30只/丛,常规稻平均为7.75只/丛,杂交稻比常规稻平均高3.91倍;四代发生量:杂交稻平 Late rice planthoppers in our county mainly include white-backed planthopper and brown planthopper. Since 1981, the number of field natural populations varies greatly from one generation to another. According to the field observation data from 1981 to 1991, in the natural conditions, the whitebacked planthopper is on the third and fourth generation of hybrid rice Population occurrence was significantly higher than conventional rice. The average yield of three generations of hybrid rice was 30.30 / clump, the average number of conventional rice was 7.75 / clump, the average of hybrid rice was 3.91 times higher than that of conventional rice;