Impact of Climate Change on Insect Pests

Agricultural systems are a complex balance of biological, agronomic and economic factors with agricultural producers closely managing crop-pest interactions. Global warming and Climate change will alter the interactions between the insect pests and their host plants. Latest assessment report from the Intergovernmental Panel on Climate Change (IPCC) predicts an increment in mean atmospheric temperature from 1.1 to 6.4°C toward the year 2100 with equally increasing atmospheric carbon dioxide (CO2). Rate of insect multiplication might increase with an increase in CO₂ and temperature. There will be reduction in the life cycle and increase in the number of generations. This will leads to diversity and abundance of arthropods, and the extent of losses due to insect pests, which will impact both crop production and food security. The activity and effectiveness of natural enemies will be a major concern in future pest management program. Geographic distributions of crops, pests, and predators are expected to shift, with pests extending to higer latitudes. A substantial expansion in high latitude and elevation of various crop insect pest distributions and is critical in temperate part of the world. Increased frequent insect outbreaks had been observed where changing climate may interfere with the induction of extended diapauses. New studies show that insect species living in warmer areas are more likely to undergo rapid population growth because they have higher metabolic rates and reproduce more frequently, thus climate change would create favorable conditions for growth in insect populations. Several approaches have been used to predict how the temperature and precipitation changes could modify the abundances, distributions or status of insect pests. Further studies on crop-pest interaction focusing on spatio-temporal variations are needed to have a better understanding and to quantify its future impacts.