Another Climate Change Headache For Farmers: Tropical Crop Pests Move North As Weather Warms Up

Hotter, more extreme weather induced by climate change is already creating huge problems for farmers, who are struggling to keep up production in the face of severe drought and unpredictable storms. Now, a new study finds that climate change is also driving hundreds of new crop pest species towards the poles.

The study, published in Nature Climate Change, examined 612 crop pests and pathogens. Tropical insects, fungi, and bacteria are moving at a rate of 1.7 miles a year toward regions normally considered too cold for them to thrive. Warmer weather has greatly expanded these pests’ territories, threatening crops unequipped with defenses against these new enemies.

American species are already feeling the effects. The mountain pine beetle, for instance, has migrated to warming forests in the Pacific Northwest, wreaking havoc on millions of acres of forest in what may be the largest forest insect blight ever seen in North America. Fusarium head blight, another pest attracted to warmer and wetter conditions up north, has decimated American wheat and oat crops, costing farmers billions of dollars. Still more pests are steadily making their way northward.

Biotech corporations such as Monsanto and Dow have genetically modified crops to resist certain pests, but studies show these crops are prompting evolutions of “super-pests” that can withstand pesticides and eat through entire fields.


New genetic modification tactics could help in the short term, but researchers called for a more sustainable shift away from the enormous monocultures of corn and soy fields that dominate North American agriculture.

“In the process of boosting food production we have also created vast monocultures of, for instance, wheat,” researcher Sarah Gurr told Discovery News. “These genetically limited plants are very vulnerable.”

Indeed, pests can easily wipe out the thousands of identical crops that characterize much of American farmland because of the lack of genetic diversity. In contrast, planting for genetic diversity can control the spread of new pests and even bolster crops’ resistance.