Hybrid megapests evolving in Brazil are a threat to crops worldwide – New Scientist

Report on Hybridization of Megapests and Its Impact on Sustainable Development Goals (SDGs)

Introduction

Two major agricultural pests, the cotton bollworm (Helicoverpa armigera) and the corn earworm (Helicoverpa zea), have interbred in Brazil, resulting in hybrid strains that carry genes conferring resistance to pesticides. This development poses a significant threat to soya and other crops in Brazil and globally, with potential consequences for food security and sustainable agriculture.

Significance to Sustainable Development Goals

This issue directly impacts several SDGs, including:

• SDG 2: Zero Hunger – Threatening global food security by potentially reducing crop yields.
• SDG 12: Responsible Consumption and Production – Challenges in pest management and sustainable agricultural practices.
• SDG 13: Climate Action – Potential increase in deforestation and greenhouse gas emissions due to expanded farmland.
• SDG 15: Life on Land – Impact on biodiversity and ecosystems through pest invasions and agricultural expansion.

Background and Current Situation

1. Megapests Overview: The cotton bollworm and corn earworm are highly destructive pests affecting a wide range of crops. The corn earworm is native to the Americas and damages crops such as corn, tomatoes, potatoes, cucumbers, and aubergines. The cotton bollworm, widespread across Eurasia, thrives on soya and other plants.
2. Introduction of Bt Soya in Brazil: Over 90% of soya grown in Brazil is genetically modified Bt soya, which produces a protein toxic to many insects, helping to control pest populations and sustain crop yields.
3. Hybridization Discovery: Genetic analyses revealed hybrids between H. armigera and H. zea in Brazil, with gene exchanges conferring resistance to Bt toxins and pyrethroid insecticides.

Implications for Food Security and Environment

• Crop Yield Reduction: Resistance in pests could lead to decreased effectiveness of Bt crops, lowering yields and increasing food prices.
• Deforestation and Emissions: To compensate for yield losses, farmers may clear additional land, leading to increased deforestation and greenhouse gas emissions.
• Global Food Supply: Brazil’s soya exports are critical for feeding both people and livestock worldwide, emphasizing the global impact of pest resistance.

Challenges in Pest Management

1. Resistance Spread: Resistance genes have spread across species and regions, complicating control efforts.
2. Compliance Issues: Guidelines for planting non-Bt refuges to slow resistance development are often not followed.
3. Development of New Bt Crops: New genetically modified crops producing multiple Bt proteins are being introduced, but their development is costly and slow.
4. Evolution Within Species: Resistance can also evolve independently within pest species, as observed in China.

Recommendations for Sustainable Pest Management

• Enhance adherence to resistance-management practices, including planting refuges of non-Bt crops.
• Invest in research and development of new Bt crop varieties with multiple resistance traits.
• Promote international collaboration to monitor and manage pest resistance and hybridization.
• Integrate pest management strategies that align with SDGs to ensure sustainable agricultural productivity and environmental conservation.

Conclusion

The hybridization of cotton bollworm and corn earworm in Brazil represents a significant challenge to sustainable agriculture and global food security. Addressing this issue is critical to achieving the Sustainable Development Goals, particularly those related to hunger, responsible production, climate action, and biodiversity. Coordinated efforts in pest management, policy enforcement, and scientific innovation are essential to mitigate the risks posed by these evolving megapests.

Image Reference

1. Sustainable Development Goals (SDGs) Addressed or Connected

1. SDG 2: Zero Hunger
   • The article discusses threats to global food security due to pesticide-resistant pests affecting soya and other crops.
2. SDG 12: Responsible Consumption and Production
   • Issues related to genetically modified Bt crops and pesticide resistance highlight the need for sustainable agricultural practices.
3. SDG 13: Climate Action
   • Increased deforestation and greenhouse gas emissions caused by expanding farmland as a response to crop yield losses are climate-related concerns.
4. SDG 15: Life on Land
   • The spread of invasive pest species and their impact on ecosystems and biodiversity is relevant to this goal.

2. Specific Targets Under Those SDGs Identified

1. SDG 2: Zero Hunger
   • Target 2.3: By 2030, double the agricultural productivity and incomes of small-scale food producers, including through sustainable food production systems.
   • Target 2.4: Ensure sustainable food production systems and implement resilient agricultural practices.
2. SDG 12: Responsible Consumption and Production
   • Target 12.4: Achieve environmentally sound management of chemicals and all wastes throughout their life cycle.
   • Target 12.5: Substantially reduce waste generation through prevention, reduction, recycling, and reuse.
3. SDG 13: Climate Action
   • Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters.
   • Target 13.2: Integrate climate change measures into national policies, strategies, and planning.
4. SDG 15: Life on Land
   • Target 15.8: Introduce measures to prevent the introduction and significantly reduce the impact of invasive alien species on land and water ecosystems.
   • Target 15.1: Ensure the conservation, restoration, and sustainable use of terrestrial and inland freshwater ecosystems.

3. Indicators Mentioned or Implied to Measure Progress

1. Crop Yield and Productivity
   • Yield reductions in soya and other crops due to pest resistance can be measured to assess agricultural productivity (related to SDG 2 targets).
2. Prevalence of Pest Resistance Genes
   • Genetic analysis of pest populations to detect resistance genes (e.g., Bt toxin resistance, pyrethroid resistance) can serve as an indicator of pest management effectiveness.
3. Extent of Deforestation and Greenhouse Gas Emissions
   • Changes in deforestation rates and associated emissions due to agricultural expansion can be monitored (related to SDG 13 targets).
4. Adoption of Sustainable Pest Management Practices
   • Compliance with guidelines such as planting non-Bt refuges to slow resistance development can be tracked.
5. Spread and Impact of Invasive Species
   • Monitoring the distribution and hybridization of megapests like Helicoverpa armigera and H. zea to evaluate ecological impact.

4. Table: SDGs, Targets and Indicators

Source: newscientist.com