Experts Propose Framework to Strengthen Insect Resistance Management for Bt Crops

Experts from Syngenta Biotechnology (China) Co., Ltd. and the Chinese Academy of Agricultural Sciences have developed a new evidence-based framework to help improve insect resistance management (IRM) for commercially grown Bt crops. The framework provides developers, regulators, and stewardship programs with a structured approach to interpret resistance signals and determine when action is needed to protect the long-term effectiveness of Bt technology.

The proposed framework draws on lessons from Bt maize and Bt cotton and links preventive IRM measures with resistance monitoring, evidence assessment, and appropriate responses. It classifies resistance into four operational stages: baseline susceptibility, early-warning signal, confirmed field-evolved resistance, and practical resistance. For each stage, the researchers outline the minimum evidence required for verification and recommend corresponding actions, such as continued monitoring, confirmation of resistance, mitigation measures, or changes in deployment strategies.

The researchers conclude that the framework can help distinguish isolated anomalies from confirmed resistance, allowing timely and proportionate responses. They say the approach could support more transparent, science-based post-market stewardship and help preserve the effectiveness of Bt crops against insect pests over the long term.

For more information, read the study from GM Crops & Food.