转 Bt基因抗虫棉新棉 33B具有高抗棉铃虫、丰产性好等特点 ,能够大幅度减少棉田用药。 1 997～1 998年 ,河北省种植的新棉 33B棉田基本未用药防治棉铃虫 ,广谱性杀虫剂基本未使用 ,因此 ,棉田生态环境得到明显改善。连续两年调查 ,棉田天敌种类增加 ,数量明显增多。 1 998年在 Bt transgenic cotton new cotton 33B with high resistance to bollworm, good yield and other characteristics, can significantly reduce the cotton field medication. From 1997 to 1998, cotton bollworms were basically not used in new cotton 33B cotton fields planted in Hebei Province, and broad-spectrum insecticides were basically unused. Therefore, the ecological environment of cotton fields was obviously improved. For two consecutive years of investigation, natural enemies in cotton fields increased in number and significantly increased in number. 1 998 years old