The V410L kdr allele in the VGSC confers higher levels of field resistance to permethrin in urban mosquito populations of Aedes aegypti (L.)

Females of Aedes aegypti transmit emerging arboviruses including Zika, dengue, yellow fever, and chikungunya. Their control heavily relies on synthetic insecticides, particularly pyrethroids. However, insecticide resistance development in populations poses a significant challenge to vector control, particularly from knockdown resistance (kdr) mutations in the voltage-gated sodium channel (VGSC), the target of pyrethroids. This study investigated the field efficacy of Permanone, a pyrethroid-based insecticide, against Ae. aegypti by assessing the impact of three common kdr mutations (V410L, V1016I, F1534C) on mosquito survival under realistic control conditions and quantifying the pesticide delivered in the field. Field cage tests (FCTs) were performed during operational mosquito control efforts in six areas of Harris County, TX, USA. Female mosquitoes were exposed to Permanone applied via handheld sprayer. Aluminum boats placed near cages collected insecticide residues, which were quantified using gas chromatography–mass spectrometry. Mosquito mortality was recorded, and individuals were genotyped for kdr mutations. A probit regression model was used to analyze the factors influencing mosquito survivorship. As the distance from the application source route increased, the amount of Permanone deposited decreased, resulting in higher survivorship of Ae. aegypti females with the triple-resistant kdr genotype (LL/II/CC). The L allele at position 410 significantly increased resistance, particularly when combined with other mutations. This study linked the survival probabilities of mosquitoes to both kdr genotype and field-measured pesticide exposure. Pesticide quantification, control efficacy results and genotyping allowed us to empirically determine the impact of genotypic resistance on vector control in the field.