我国自从50年代水稻改制后,长江流域和华南地区三化螟种群上升,二化螟种群全面下降。70年代末期全国大面积推广杂交稻以后,长江流域广大稻区三化螟种群下降,二化螟种群回升,而华南地区则以三化螟为主,二化螟很少。由于长江流域和华南地区自然因素的差异及其局部地区社会因素的差异,使耕作制度产生区域性差异,进而使苗情与虫情及其相互对应状况,也产生区域性差异,从而形成了稻螟优势种群区域化的局面。 Since the rice reform in the 1950s in our country, the populations of the three rice borer, Chilo suppressalis along the Yangtze River and South China have risen, and the population of the Chilo suppressalis Walker has declined. After the large-scale popularization of hybrid rice in the late 1970s, the populations of the three rice borer in rice-growing areas in the Yangtze River valley decreased and the population of the rice stem borer rose. The stem borer was the main species in southern China, but the stem borer was few. Due to the differences of natural factors in the Yangtze River valley and South China and the differences in social factors in some areas, the differences in farming system have resulted in regional differences, thus resulting in the regional differences in seedling conditions and insects as well as the mutual corresponding conditions, resulting in the formation of rice Regionalization of dominant populations of Borer.