Abstract: Culex quinquefasciatus Say, member of the Culex pipiens complex and commonly known as the southern house mosquito, is present in the Americas, Australia, Asia, Africa, Middle East and New Zealand. This species, considered a nuisance due to their aggressive and nocturnal biting behavior, is also a vector of several pathogens, including the Wulchereria bancrofti (bancroftian filariasis) and the West Nile virus. Aedes aegypti (Linnaeus), commonly known as the yellow fever mosquito, is an important vector of arboviruses such as dengue, chikungunya and Zika. Cx. quinquefasciatus and Ae.aegypti are both abundantly present in Miami-Dade County. In 2020, West Nile Virus became increasingly prevalent resulting in 60 WNV human cases. In addition, the County received 491 referrals from the Florida Department of Health, for suspected cases of dengue, chikungunya and Zika as of September 20, 2022. Eighteen confirmed local cases of Dengue have been reported. Control of the mosquito species that spread these viruses can be done through the use of wide area adulticide applications using truck-mounted sprayers. The efficacy of these treatments is highly dependent on the insecticide susceptibility status of the local mosquito populations. Miami-Dade Mosquito Control in partnership with UF/IFAS Florida Medical Entomology Laboratory has been conducting insecticide resistance monitoring on adult mosquitoes since 2020. Cx. quinquefasciatus and Ae. aegypti eggs from 52 different locations were tested. Bottle bioassay results showed 0 to 51% mortality from pyrethroids for Cx. quinquefasciatus while organophosphates showed 76 to 100%. Bottle bioassay results showed 0 to 55% mortality from pyrethroids for Ae. aegypti while organophosphates showed 100%. Based on their individual flight characteristics, a GIS layer of buffer regions was mapped around known active sites: 1mile buffer for Cx. quinquefasciatus and 0.2 mile buffer for Ae. aegypti. This was done to coordinate adulticiding applications based on resistance data.
