July 1, 2021 | Yellow fever mosquitoes (Aedes aegypti) are evolving resistance to the pyrethroid insecticide permethrin, according to a study published by Colorado State University researchers in PLOS Genetics, highlighting the need to adopt ecologically-based mosquito management. Widespread, intensive use of the pesticide in mosquito control has allowed genetic mutations to persist among these mosquito populations, causing subsequent resistance to permethrin. Pyrethroids are one of the few remaining classes of insecticides available to control yellow fever mosquitoes, and resistance threatens the ability to prevent disease outbreaks with chemical-intensive methods. Two common pyrethroid resistance mechanisms occur among yellow fever mosquitoes: knockdown resistance involving “amino acid substitutions at the pyrethroid target site—the voltage-gated sodium channel (VGSC); [and] enhanced metabolism by detoxification enzymes.” Whether a mosquito displays a resistance or knockdown response to insecticide exposure depends on pyrethroid concentration and genetic background. [Saavedra-Rodriguez, Karla et al. Permethrin resistance in Aedes aegypti: Genomic variants that confer knockdown resistance, recovery, and death. PLOS Genetics. 17(6): e1009606, 2021
