Parvizi, ElaheBachler, AndyZwick, AndreasWalsh, Tom K.Moritz, CraigMcGaughran, Angela2025-06-112025-06-111010-061XPubMed:38824398ORCID:/0000-0001-5313-7279/work/170522717http://www.scopus.com/inward/record.url?scp=85200338510&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733759002In response to environmental and human-imposed selective pressures, agroecosystem pests frequently undergo rapid evolution, with some species having a remarkable capacity to rapidly develop pesticide resistance. Temporal sampling of genomic data can comprehensively capture such adaptive changes over time, for example, by elucidating allele frequency shifts in pesticide resistance loci in response to different pesticides. Here, we leveraged museum specimens spanning over a century of collections to generate temporal contrasts between pre- and post-insecticide populations of an agricultural pest moth, Helicoverpa armigera. We used targeted exon sequencing of 254 samples collected across Australia from the pre-1950s (prior to insecticide introduction) to the 1990s, encompassing decades of changing insecticide use. Our sequencing approach focused on genes that are known to be involved in insecticide resistance, environmental sensation, and stress tolerance. We found an overall lack of spatial and temporal population structure change across Australia. In some decades (e.g., 1960s and 1970s), we found a moderate reduction of genetic diversity, implying stochasticity in evolutionary trajectories due to genetic drift. Temporal genome scans showed extensive evidence of selection following insecticide use, although the majority of selected variants were low impact. Finally, alternating trajectories of allele frequency change were suggestive of potential antagonistic pleiotropy. Our results provide new insights into recent evolutionary responses in an agricultural pest and show how temporal contrasts using museum specimens can improve mechanistic understanding of rapid evolution.This work was funded by the Australian Research Council (Discovery Early Career Researcher Award DE160100685 to A.M.) and Commonwealth Scientific and Industrial Research Organisation (Sequencing lane to A.M.). We wish to thank several museums and/or government departments across Australia for providing samples (including the Australian National Insect Collection, Canberra; the Department of Agriculture and Food, Western Australia; the Department of Agriculture and Fisheries, Queensland; the Agricultural Scientific Collections Trust, New South Wale; and Museum Victoria, Victoria). This work was funded by the Australian Research Council (Discovery Early Career Researcher Award DE160100685 to A.M.) and Commonwealth Scientific and Industrial Research Organisation (Sequencing lane to A.M.). Acknowledgments11enPublisher Copyright: © The Author(s) 2024.cotton bollwormgenetic driftinsecticide resistancemuseum genomicsselection202410.1093/jeb/voae06885200338510