据调查,危害我县晚稻的飞虱有八种之多,而发生量大、危害较重的是褐飞虱。但近年来,田间飞虱种群数量发生了很大变化,即褐飞虱比例下降,白背飞虱比例上升,尤以杂交晚稻田变化最明显。据1980—1983年6—10月县中心测报站灯下诱集飞虱虫口资料表明:1980年以褐飞虱为主,占74.71%, According to the survey, there are eight kinds of planthopper that endanger the late rice in our county, and the large amount of planthopper that is harmed is brown planthopper. However, in recent years, the population of planthoppers has undergone great changes, that is, the proportion of brown planthopper decreased, the proportion of white-backed planthopper increased, especially in late hybrid rice. According to the information collected from the lamppost of the planthopper at the county center during the period from June to October of 1980-1983, it was found that the brown planthopper was the dominant species in 1980, accounting for 74.71%