Effects of Bt crops on non-target insect pests

Abstract

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.