Aedes aegypti

Abas, Amri S., Simfukwe, Alfred J., Masalu, John P., Kahamba, Najat F., Nambunga, Ismail H., Msaky, Dickson S., Limwagu, Alex J., Kipekepeke, Abdallah R., Wergin, Carsten, Njalambaha, Rukiyah M., Kemibala, Elison E., Seleman, Amour, Mlacha, Yeromin P., Finda, Marceline, Beisel, Uli, Kimaro, Esther G., Ngowo, Halfan S. & Okumu, Fredros O., 2024, Risk of AEdES-borne diseases in and around the Tanzanian seaport of Tanga despite community members being more concerned about malaria, Parasites & Vectors (512) 17 (1), pp. 1-16 : 10

Susceptibility of Aedes aegypti mosquitoes to public health insecticides

Susceptibility tests for female Ae. aegypti mosquitoes aged 3–5 days were conducted against five insecticides at various concentrations, including permethrin (0.75%, 3.75%), deltamethrin (0.05%, 0.5%), pirimiphos-methyl (0.25%, 1.25%), DDT (4%), and bendiocarb (0.5%, 1%). At 24 h post-exposure, the average mortality rates for Ae. aegypti exposed against bendiocarb (1%) and DDT (4%) were 98.8% and 100%, respectively, indicating full susceptibility. Te average mortalities associated with pirimiphos-methyl (0.25%) and deltamethrin (0.05%) were 94.4%, 93.8%, respectively, suggesting possible or unconfirmed resistance. Increasing the dose of deltamethrin to 0.5% increased the 24-h mortality to 96.3%, suggesting that even at this dose the mosquitoes were still slightly resistant. Tests against permethrin showed average mortality rates of 73.8% and 88.8%, indicating clearly confirmed resistance even at the five times higher dose of 3.75%. In contrast, the Ae. aegypti mosquitoes were fully susceptible to DDT and bendiocarb ( Fig. 3 ).

Figures

Fig. 3 Results of the susceptibility tests for female Ae.aegypti mosquitoes showing mean mortality after 24 h of monitoring post-exposure to the candidate insecticides.The dotted green lines (≥98% mortality) indicate full susceptibility, while the dotted blue lines (90–98% mortality) indicate possible resistance or unconfirmed resistance requiring confirmation