4. Use and Efficacy of Bt Compared to Less Environmentally Safe Alternatives

Bt is classified as a biopesticide. Market surveys from several states in the United States of America suggest that the main reason for using biopesticides is it is considered safe for the environment. Public perception and organic farming have risen in importance as reasons for using biopesticides. However, the main reason for not using biopesticides continues to be perceptions of low efficacy, while higher costs and lack of awareness appeared to have less significance. Even though limited by its narrow activity, Bt usage has increased significantly over the years. The narrow activity spectrum of Bt is to its advantage for it is well suited for IPM programs that preserve large segments of indigenous invertebrate predator and parasitoid populations. On the other hand, usage of broad spectrum pesticides that also kill non-target beneficial insects, may lead to pest outbreak when the pesticide loses efficacy due to pest resistance. Less environmentally safe pesticides also have their roles to play in IRM and IPM programs. When combined with practices in IPM, they will have even less effect on the environment while reducing the probability of resistance. Substantial economic returns and environmental safety will drive the usage of safe pest control measures, which Bt may play a significant role.