淳安县在90年代中期以前二化螟主要分布在山区丘陵中的单季稻区、单双混栽区危害，一般每年发生3代。自90年代中期以来，由于在原双季稻区中单季稻种植面积的不断扩大，春花作物免耕技术的普及，为二化螟的转化危害和种群基数的逐年增加，创造了良好的栖息场所和食料条件，最终 Chun’an County in the mid 90s before the Chilo suppressalis are mainly distributed in mountain hills in the single season rice area, single and double planting area hazards, the general occurrence of 3 generations per year. Since the mid-1990s, due to the continuous expansion of single-season rice planting area in the original double cropping rice area, the popularization of no-tillage technology for spring flowers has created a good habitat and foodstuff for the transformation of the stem borer (Chilo suppressalis) and its population base year by year Conditions, eventually