Life-history adaptation under climate warming magnifies the agricultural footprint of a cosmopolitan insect pest

Abstract

Climate change is affecting population growth rates of ectothermic pests with potentially dire consequences for agriculture, but how rapid genetic adaptation impacts these dynamics remains unclear. To address this challenge, we predicted how climate change adaptation in life-history traits of insect pests may affect future agricultural yields by unifying thermodynamics based on first principles with classic life-history theory. Our model predicts that warming temperatures favour changes in resource allocation decisions coupled with increased larval host consumption, resulting in a predicted double-blow on agricultural yields under future climate change. We find support for these predictions by studying thermal adaptation in life-history traits and underlying gene expression in the wide-spread insect pest, Callosobruchus maculatus, with five years of life-history evolution under experimental warming causing an almost two-fold increase in its predicted agricultural footprint. These results emphasize the need for integrating a mechanistic understanding of life-history evolution into forecasts of pest impact.