The southern house mosquito Culex quinquefasciatus in Abu Dhabi, UAE, is developing resistance to deltamethrin insecticide

Culex quinquefasciatus is a widely spread mosquito species that poses a significant public health threat in many countries. This insect vector is present in the United Arab Emirates (UAE), yet no studies have been conducted on its resistance to any insecticide group. Research shows that controlling mosquitoes is crucial to eliminating mosquito-borne diseases, but when these vectors develop insecticide resistance, the situation can escalate dangerously out of control. This study aimed to identify a knockdown resistance (kdr) mutation L1014F using molecular tools. Additionally, it aimed to assess deltamethrin resistance using the Centers for Disease Control and Prevention (CDC) bottle bioassay. We screened Cx. quinquefasciatus adults (N = 174) for the presence of the mutation using allele-specific PCR (AS-PCR) and DNA sequencing. We detected the mutation and found the kdr allele in all the sampled locations. Furthermore, the CDC bottle bioassay revealed deltamethrin resistance from only one sampling location. To our knowledge, this is the first report of insecticide resistance in Cx. quinquefasciatus in the UAE. Our findings show the need for continued insecticide resistance monitoring for effective mosquito control in the UAE.