crop losses to insects

Climate Change and Crop Losses

  • Insects reduce yields of rice, maize, and wheat significantly.

  • Models rarely include insect pest impacts on crops due to climate warming.

Yield Loss Projections

  • Global yield losses expected to increase by 10-25% per degree Celsius increase in temperature.

  • Most severe losses anticipated in temperate regions where most grain is produced.

Insect Metabolism and Growth

  • Insect metabolic rates (M) increase with temperature; consumption rates must also increase accordingly.

  • Population growth rates (n) of insects vary with temperature, potentially declining in tropical regions while rising elsewhere.

  • Changes in these rates affect total energy consumption of pest populations, influencing crop yields.

Methodology

  • Relationships between temperature and insect physiology incorporated into a demographic model to predict changes in yield loss.

  • Projections based on climate models (RCP8.5 scenario) and historical temperature data.

Results Summary

  • With a 2°C temperature increase, yield loss increases: 46% for wheat, 19% for rice, and 31% for maize.

  • Total yield losses: 59, 92, and 62 metric megatons annually for wheat, rice, and maize, respectively.

  • Global losses consistent across climate models despite uncertainties.

Geographic Impacts

  • Strong impact in temperate regions versus weaker in tropical regions due to different population growth dynamics.

  • Major agricultural countries (U.S., China, France) expected to experience significant losses.

Future Adaptations

  • Farmers may need to alter planting dates, crop rotations, and increase pesticide usage to maintain yields.

  • The effects of climate warming on pests highlight the urgency of developing sustainable pest management strategies.

Societal Implications

  • Increased pest-related yield losses may exacerbate food scarcity for vulnerable populations, especially in developing regions.

Conclusion

  • Awareness and proactive measures needed to mitigate climate effects on agriculture and ensure food security in the face of rising insect pressures.