How climate is re-shaping pest populations globally
As climate changes present new challenges for agriculture, innovative solutions and proactive strategies are needed more than ever to safeguard crops and create more resilient agroecosystems.
The persistent rise in global temperatures and the frequency of extreme weather events are altering habitats and expanding the territories of pests and diseases. This shift poses a significant threat to agricultural productivity and food supply chains.
Milder winters and fewer extreme freezes will increase the rate at which overwintering insects will survive. This leads to larger populations that are ready to infest and spread when favorable conditions return.
Some pests and diseases rely on being airborne for greater dispersion away from their current habitats. With the increase in storms that tend to spread across multiple regions, these pests are getting a free ride into new territories. New diseases or insects can show up during critical times in a crop’s development.
Unpredictable precipitation, whether that’s flooding or drought, can weaken a plant’s defenses against insect damage or diseases. Heavy rains can also alter the population dynamics of predator and prey species, potentially leading to increased pest populations.
As global temperatures rise, the geographical range suitable for many pests and pathogens also expands. This leads to the migration of pests and diseases into new areas where they previously could not survive, affecting new host species and ecosystems.
Case studies
The bacterium Erwinia stewartii, the pathogen that causes Stewart’s Wilt in corn, can only survive over a cold winter inside the gut of corn flea beetles (Chaetocnema pulicaria). This beetle pest is common in many parts of the Southern US, where resistant varieties of corn have been developed to deal with this vectoring pest. Corn growers in northern regions may see a few corn flea beetles each year, but hard freezes knock down the potential for major outbreaks. However, what happens when northern growers experience warmer winters? More beetles survive, the disease spreads, and farmers lose a significant amount of yield. Recent research incorporated climate data from climate data and modeling tool PRISM into existing models to make more accurate predictions about the risk of outbreaks in the coming decades. That gives farmers, entrepreneurs, and researchers ahead start on these pests.
The olive fruit fly (Bactrocera oleae) significantly impacts Mediterranean olive production. Climate change has increased temperatures, allowing the fly to complete more life cycles annually and invade northern Europe's emerging olive farms. In response, researchers are developing automated IPM tools for monitoring and sterile insect releases to reduce populations.
The fall armyworm (Spodoptera frugiperda), a devastating pest to maize, has spread rapidly across Sub-Saharan Africa, aided by altered rainfall patterns and warmer temperatures. Governments and international bodies are countering this threat with Integrated Pest Management(IPM) strategies. These include deploying biological control agents like parasitic wasps and educating farmers on manual pest control techniques to safeguard food security.
For Future Farmers
Climate is reshaping the world of agriculture, creating new challenges as pests expand their ranges, increase in number, and strike at more vulnerable crops. These shifts underscore the urgency of developing innovative, science-driven strategies to safeguard food security.
By leveraging predictive tools, finding new treatments that are safe for the environment and integrating them with biologicals and advanced pest management systems, farmers and researchers are finding ways to stay ahead of these evolving threats. The fight against pests in a changing climate will require global collaboration and continuous adaptation, ensuring that agriculture remains resilient in the face of this pressing environmental challenge.
Linked image: Tasha Kostyuk/Unsplash
