转Bt基因抗虫作物对非靶标害虫的影响

转基因作物的长期大面积种植, 在为农业生产带来惠益的同时, 对农业生态系统的健康和稳定可能会产生潜在的影响。转基因作物表达的Bt蛋白对靶标害虫起到较好的控制效果, 而对Bt蛋白不敏感的非靶标害虫种群可能会迅速发展起来, 对作物造成为害。随着抗虫转基因作物的连续多年种植, 科学家们对于田间杀虫剂施用量的增减看法不尽一致。通过总结已有的研究报道, 本文以Bt玉米和Bt棉花为例, 分析了大田中非靶标害虫暴发的现状, 以及暴发的主要原因(如杀虫剂的使用、害虫天敌减少和物种替代)。在生产实践中, 抗虫作物的长期大面积释放导致广谱杀虫剂施用量减少, 田间非靶标害虫数量上升。因此今后需要继续开展更多的研究来综合评估种植转Bt基因作物产生的长期潜在影响, 优化害虫防治措施, 避免非靶标害虫暴发。

Effects of Bt crops on non-target insect pests

The long-term large-scale planting of genetically modified (GM) crops may have potential impacts on the health and stability of agricultural ecosystems while benefitting agricultural production. Bt proteins expressed in Bt crops have a good control on target pests. However, non-target insects that are not susceptible to Bt toxins may have increased populations rapidly, causing significant damage to crops. With the long-term continued cultivation of insect-resistant GM crops, different reports and views on the amounts of pesticide applications have been reported. Based on existing research, we reviewed the characteristics and status of non-target insect pest outbreaks and analyzed the main causes of the outbreaks (such as insecticide use, decrease of natural enemies, and species replacement). In addition, we discussed the effects of GM crops on non-target pests over long-term cultivation using Bt corn and cotton as examples. Given the existing problems of non-target insect outbreaks due to commercial applications of Bt crops, further studies on monitoring the efficacies of insect-resistant GM crops are necessary to prevent outbreaks of non-target pests needed for sustainable agriculture.