Allelic Survey and Population Genomics in a Hotspot of Diflubenzuron Resistance in the Mosquito Culex pipiens

Abstract

Simple Summary The mosquito Culex pipiens is a primary disease vector worldwide, and chemical insecticides have been the most widely employed control tool. Recently, insecticide resistance to diflubenzuron, a larvicide commonly used in mosquito control, has been documented in Cx. pipiens populations from the Emilia-Romagna region, Italy. In this study, we furnished an updated picture of the distribution and frequency of resistance-associated alleles and, by exploiting population genomics, we investigated the population structure across the region. Our results showed that diflubenzuron-resistance-associated alleles are still present in Emilia-Romagna and that their relative frequency is higher in central-eastern than in western provinces. Furthermore, they revealed a highly homogeneous gene pool across the region, posing the risk of the spread of resistance alleles. Overall, this study highlights the importance of continuously monitoring Cx. pipiens populations and, from an applied perspective, it provides relevant information to plan effective control programs.