Investigation of insecticide resistance profile of St. Johns County populations of Aedes aegypti and Aedes albopictus to permethrin

The prolonged use of permethrin-based products over 20 years has posed a risk of developing insecticide resistance in mosquitoes in St. Johns County, Florida, where Ae. aegypti and Ae. albopictus co-exist. Insecticide resistance to permethrin was investigated on the two invasive Aedes mosquitoes collected from St. Augustine, St. Johns County. Centers for Disease Control and Prevention (CDC) bottle bioassays on individual Aedes mosquitoes were conducted for 2 hours. At the diagnostic time, the mortality rates of Ae. aegypti and Ae. albopictus were 6.59% and 55.36%, respectively. This suggests that both Aedes species are resistant to permethrin. Based on a log-rank test, their mortality rates were significantly different (p < 0.001). The finding indicates the inefficiency of permethrin-based products targeting St. Augustine Ae. aegypti and Ae. albopictus populations.