水稻螟虫是重要的农业害虫，长期以来主要采用化学药剂防治，其抗性发展问题受到国内外广泛关注。１９９５年抗性监测结果表明，二化螟对敌百虫、甲胺磷、对硫磷等有机磷杀虫剂产生了６１～８倍的抗药性，对杀虫单的抗性系数达１３１［１］。生物杀虫剂苏云金杆菌（Ｂｔ）? Rice stem borer is an important agricultural pest, which has long been mainly used for chemical control. The development of its resistance has drawn wide attention both at home and abroad. In 1995, the results of resistance monitoring showed that the resistance of Chilo suppressalis to organophosphate insecticides such as trichlorfon, methamidophos and parathion was 6-1 to 8 times higher, 13  1 [1]. Biopesticide Bacillus thuringiensis (Bt)?