Climate change and pesticide resistance: a synthesis on emerging mechanisms and evolutionary dynamics

Pesticide resistance is a growing threat to global food security and crop protection. Beyond chemical overuse, climate change is increasingly recognized as a major driver that can reshape selection and resistance evolution. Here, we synthesize experimental evidence and plausible pathways by which warming and extreme climate events influence insecticide resistance. We first evaluate how resistance mechanisms respond to climatic stressors, including target-site insensitivity, enhanced detoxification, reduced penetration, and behavioral avoidance. We then map climate drivers to changes in resistance-allele frequencies by altering fitness gains and costs of resistance through mostly positive effects on voltinism and population abundance, distribution shifts and migration, and consequent increased insecticide use and selection pressure. Finally, we identify high-risk resistance pests and insecticides under climate change, emphasizing pests with high thermal tolerance and rapid reproduction and insecticides whose efficacy declines with temperature. We conclude that climate change can either facilitate or suppress resistance depending on pest thermal ecology and buffering capacity, the dominant resistance mechanism, mode-of-action-specific temperature-toxicity relationships, and critically, the distinction between short-term phenotypic resistance and multi-generation evolutionary trajectories.