The Yellow fever mosquito (scientific name, Aedes aegypti) spreads multiple untreatable viruses in humans and is primarily controlled using a pesticide called permethrin. However, many mosquitoes are evolving resistance to the pesticide. A new study by Karla Saavedra-Rodriguez of Colorado State University and colleagues, published in the journal PLOS Genetics, identifies mutations linked to different permethrin resistance strategies, which threaten our ability to control disease outbreaks.