The impact of nutrition on insecticide resistance and gene expression in Aedes aegypti

The development of insecticide resistance in Aedes aegypti, a major vector of medically important arboviruses such as dengue virus, Zika virus, and chikungunya virus, poses a significant challenge to vector control efforts worldwide, especially in urban and endemic regions like South Texas. Insecticides remain a common method for mosquito management; however, their widespread use has accelerated the evolution of resistance mechanisms, particularly metabolic resistance mediated by cytochrome P450 enzymes. Previous studies have demonstrated that environmental factors, such as larval nutrition, may influence mosquito physiology and the expression of resistance-associated genes, but this relationship is still poorly understood. Our study aims to investigate how varying nutritional conditions during the larval stage affect the expression of key cytochrome P450 genes (CYP6 and CYP9 families) linked to pyrethroid resistance in Aedes aegypti. Larvae were fed one of five different food treatments with varied ratios of lipids and proteins. Once mosquitoes emerged as adults, they were exposed to permethrin using CDC bottle bioassays. Known susceptible and resistant strains were tested alongside South Texas field-collected populations for comparison. Surviving mosquitoes were tested for enzymatic activity using quantitative PCR. We hypothesize that treatments containing the highest amount of carbohydrates relative to protein will show the highest gene expression of cytochrome P450. These data will ideally provide insights into how nutrition shapes resistance, and to inform more effective strategies for vector management, including the potential manipulation of food resources to enhance the impact of control efforts.