Climate change, transgenic corn adoption and field-evolved resistance in corn earworm

Area of Science:

• Agricultural Science
• Entomology
• Climate Change Research

Background:

• Transgenic Bacillus thuringiensis (Bt) crops are widely adopted for insect pest control.
• Rising global temperatures impact insect biology and agricultural pest management strategies.
• The combined effects of climate change and Bt crop use on insect resistance are not well understood.

Purpose of the Study:

• To investigate the relationship between temperature anomalies, Bt crop adoption, and the evolution of resistance in the corn pest Helicoverpa zea.
• To assess how climate change influences the efficacy of Bt crops and pest management.

Main Methods:

• Analysis of field-evolved resistance to Cry1Ab Bt sweet corn in Helicoverpa zea populations.
• Correlation of temperature anomaly data (1996-2016) with Bt crop adoption rates.
• Evaluation of H. zea damage, developmental stages, and population dynamics in relation to temperature and Bt selection pressure.

Main Results:

• Bt crop adoption initially suppressed H. zea populations, but rising temperatures mitigated this effect.
• Temperature anomalies, interacting with high Bt crop acreage, likely accelerated the development of insect resistance.
• Increased H. zea damage and altered pest development were observed with higher Bt adoption and temperature anomalies.

Conclusions:

• Climate change poses significant challenges to the long-term effectiveness of Bt crop technology.
• The spread of Bt-resistant H. zea is a high risk due to widespread Bt adoption and climate-driven population dynamics.
• Integrating climate change and evolutionary dynamics into Bt resistance management programs is crucial.