Adaptive evolution to thermal stress underpins climate resilience in a cosmopolitan arthropod

Adaptive evolution enables species to survive and thrive under changing environmental conditions. In the face of accelerating global climate change, thermal stress represents a major challenge to the persistence of terrestrial ectotherms. Understanding the genetic mechanisms underlying thermal adaptation is therefore critical for predicting species evolutionary potential and future success. Here, we combine experimental evolution, phenotypic assays, and multi-omics analyses to investigate the adaptive responses of the diamondback moth (Plutella xylostella), a globally destructive pest of cruciferous crops, to contrasting thermal environments. Populations evolved under hot (32{degrees}C/27{degrees}C) and cold (15{degrees}C/10{degrees}C) regimes exhibited distinct demographic and fitness traits relative to those maintained under favorable conditions (26{degrees}C). Integrated transcriptomic and metabolomic analyses revealed extensive transcriptional reprogramming and metabolic adjustments associated with temperature adaptation. Key pathways involved in lipid metabolism and DNA methylation were enriched, while functional validation using CRISPR-Cas9 confirmed that a mutant allele of PxSODC enhances superoxide dismutase activity and improves tolerance to thermal extremes. Together, these findings provides critical insights into this arthropods capacity for global dispersal and likely persistence under climate change, establishing a framework for understanding equivalent effects in other species.