Researchers say overuse of rootworm-resistant Bt corn threatens long-term crop viability.
A new study warns that the widespread planting of genetically engineered Bt maize in the U.S. Corn Belt has accelerated corn rootworm resistance reducing the crop’s long-term effectiveness and costing American farmers an estimated $1.6 billion in economic losses. Researchers emphasize the urgent need for greater seed diversity improved transparency and informed decision-making to sustain the benefits of transgenic crops.
The study published by the American Association for the Advancement of Science (AAAS) analyzed data from ten Corn Belt states over 12 years. Researchers found that while Bt corn initially suppressed rootworm populations overplanting and seed trait bundling led to widespread resistance.
“If current and future related innovations are managed as Bt maize hybrids have been” the authors stated in the paper. “We risk entering a cycle of rapid obsolescence among transgenic technologies.”
How Overplanting Bt Corn is Driving Resistance
Bt crops which contain insecticidal proteins from Bacillus thuringiensis (Bt) have historically helped increase yields by minimizing pest damage. However as usage rises corn rootworms evolve resistance reducing the effectiveness of Bt hybrids. This phenomenon mirrors the tragedy of the commons where individual short-term decisions lead to the depletion of a shared resource.
Key Findings: Economic Impact and Root Causes
The study reveals that from 2014 to 2016 Bt corn was often planted excessively particularly in the eastern Corn Belt where pest pressure was low. The result?
- Minimal pest suppression benefits
- Higher costs for transgenic seeds
- Depleting the rootworm susceptibility pool
- An estimated $1.6 billion in economic losses
Researchers point to misconceptions about pest pressure lack of farmer education and market-driven seed bundling practices as primary drivers of overplanting.
The Path Forward: Balancing Innovation with Sustainability
According to a related Policy Forum regulators must balance short-term farmer incentives with long-term agricultural sustainability to ensure Bt crops remain viable for pest management. Experts suggest:
- Enhanced education on rootworm pressures
- More transparent seed trait marketing
- Greater crop rotation and seed diversity
With pest resistance on the rise the industry faces a critical decision: adapt planting practices now or risk losing Bt corn’s effectiveness altogether.
Read more details on the study and recommendations for sustainable pest management at https://www.science.org/doi/10.1126/science.adm7634.
