Multiple insecticide resistance in Aedes aegypti populations from three different setting zones (Dandji, Awaya and Kaoura) in Benin was evaluated from July-October 2021 where firstly adult females aged to 2-5 were subjected to susceptible test using impregnated papers (Permethrin 0. 25%; deltamethrin 0.03%; DDT 4%, and bendiocarb 0.1%) following WHO testing protocol. Moreover, biochemical analysis was done in order to detect Mixed Function Oxydase (MFO), non-specific esterase (NSE) and glutathione-S-transferases (GST) activity in individual 5 days old adult Ae. aegypti that had been reared from larvae and not previously exposed to insecticides. This research showed that the wild populations of Ae. aegypti populations from all the study sites were fully susceptible to bendiocarb (100% of mortality). However, we noticed that all the populations of Ae. aegypti had developed a strong resistance to DDT with average mortalities of 16%; 20% and 26% in Dandji, Awaya and Kaoura sites respectively. Moderate resistance profiles were recorded when these mosquitoes were exposed to permethrin with average mortalities of 48% ; 54% and 62% respectively in Dandji, Awaya and Kaoura sites. For deltamethrin, only populations of Ae. aegypti from Kaoura were fully susceptible to this insecticide. However, 78% and 84% average mortalities were recorded respectively in Dandji and Awaya. Enzymatic activities (Glutathione-s-transferase (GST) and P450 monooxygenase) in the wild population of Ae. aegypti were significantly higher than the control strain SBE (P < 0,05). This study provides clear evidence that there is a multiple insecticide resistance in the three wild populations of Ae. aegypti populations from our study sites. This will jeopardise the successful of the control of Ae. aegypti in these districts, however, the susceptibility results of the three populations to bendiocarb shows that this insecticide appears to be a good candidate to control these wild populations in case of outbreak of dengue fever.
