Soybean Crops in Argentina Face Threat from Bt-Pesticide Resistant Pests

Strategic Insights -

Research by National University Litoral investigators has uncovered the alarming presence of pest populations in soybean crops in central Argentina, underscoring the pressing need for sustainable agricultural practices. The study highlights significant findings on the impact of Bt soybean on the consumption, biological cycle, and reproduction of Spodoptera cosmioides and Spodoptera eridania, species that can resist Bt pesticides.

Key Takeaways:

  • An increasing number of Spodoptera cosmioides and Spodoptera eridania have been detected in soybean crops in central Argentina, threatening agricultural production.
  • These species can tolerate the Cry1Ac insecticidal toxin, expressed by genetically modified Bt soybean (MON89788 x MON87701), making them resistant to Bt pesticides.
  • Larval feeding on Bt soybean resulted in reduced pupal periods for S. cosmioides (23% less than control) and S. eridania (11% less than control), indicating a compromised biological cycle.
  • Despite reductions in consumption and biological cycle, both S. cosmioides and S. eridania completed their reproductive cycles.
  • The study enhances our understanding of the biology of these pests in Bt soybean crops and underscores the need for careful management strategies to mitigate the impact of these resistant species.
  • The research highlights the potential for disease and pest tolerance to genetically modified crops, emphasizing the need for a multifaceted approach to agricultural sustainability.

Statistics:

  • 23% reduction in pupal period for S. cosmioides when fed on Bt soybean.
  • 14% reduction in leaf-area consumption for S. cosmioides when fed on Bt soybean.
  • 11% reduction in pupal period for S. eridania when fed on Bt soybean.
  • 13% reduction in oviposition periods (egg-laying cycles) for S. eridania when fed on Bt soybean.

Sources:

  • NewsRx. Study Findings from National University Litoral Broaden Understanding of Agriculture [Impact of Cry1ac Soybean (Glicine Max) On Biological and Reproductive Cycles and Herbivory Capacity of Spodoptera Cosmioides and Spodoptera ...]. Agriculture Week. July 24, 2025; p 357.
  • Revista De La Facultad De Ciencias Agrarias. Impact of Cry1ac Soybean (Glicine Max) On Biological and Reproductive Cycles and Herbivory Capacity of Spodoptera Cosmioides and Spodoptera Eridania (Lepidoptera: Noctuidae). 2025;57(1):93-102.