Multiple recombination events between two cytochrome P450 loci contribute to global pyrethroid resistance in Helicoverpa armigera.

PLoS One. 2018 Nov 1;13(11):e0197760. doi: 10.1371/journal.pone.0197760. eCollection 2018. Walsh TK1, Joussen N2, Tian K3, McGaughran A1,4, Anderson CJ1,5, Qiu X3, Ahn SJ6, Bird L7, Pavlidi N8, Vontas J9, Ryu J1, Rasool A10, Barony Macedo I11, Tay WT1, Zhang Y12, Whitehouse MEA13, Silvie PJ14, Downes S13, Nemec L13, Heckel DG2. Author information 1 Black Mountain Laboratories, Commonwealth Scientific and Industrial Research Organisation, Acton, Australian Capital Territory, Australia. 2 Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany. 3 State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China. 4 School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia. 5 Biological and Environmental Sciences, University of Stirling, Stirling, United Kingdom. 6 Horticultural and Herbal Crop Environment Division, National Institute of Horticultural and Herbal Science, Suwon, Korea. 7 Tamworth Agricultural Institute, New South Wales Department of Primary Industry, Calala, New South Wales, Australia. 8 Department of Biology, University of Crete, Rethymno, Greece. 9 Laboratory of Pesticide Science, Agricultural University of Athens, Athens, Greece. 10 Insect Molecular Biology Laboratory, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan. 11 Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. 12 Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China. 13 Australian Cotton Research Institute, Narrabri, New South Wales, Australia. 14 Agroécologie et intensification durable des cultures annuelles, Centre de coopération internationale en recherche agronomique pour le développement, Montpellier, France. Abstract The cotton bollworm, Helicoverpa armigera (Hübner) is one of the most serious insect pest species to evolve resistance against many insecticides from different chemical classes. This species has evolved resistance to the pyrethroid insecticides across its native range and is becoming a truly global pest after establishing in South America and having been recently recorded in North America. A chimeric cytochrome P450 gene, CYP337B3, has been identified as a resistance mechanism for resistance to fenvalerate and cypermethrin. Here we show that this resistance mechanism is common around the world with at least eight different alleles. It is present in South America and has probably introgressed into its closely related native sibling species, Helicoverpa zea. The different alleles of CYP337B3 are likely to have arisen independently in different geographic locations from selection on existing diversity. The alleles found in Brazil are those most commonly found in Asia, suggesting a potential origin for the incursion of H. armigera into the Americas.