Susceptibility status of Culex pipiens larvae (Diptera: Culicidae) to the main insecticides used in larval control in the regions of Rabat and Casablanca in Morocco
2022
Aboulfadl, Souhail | Mellouki, Fouad | Aouinty, Brahim | Faraj, Chafika
In Morocco Culex pipiens mosquitoes cause serious nuisance in most urban areas. Control programs mainly rely on chemical insecticides, but numerous failures have been reported in the area, suggesting the development of resistant populations. In this study, we determined the resistance levels of the larval populations to two organophosphates; temephos and chlorpyriphos, commonly used in four prefectures from the regions of Rabat and Casablanca. We conducted bioassays following WHO standard procedures to calculate lethal concentrations LC₅₀ and LC₉₀ then resistance ratios by dividing values for the tested strains by those of the susceptible strain. We show that larval populations of Cx. pipiens developed resistance to temephos and chlorpyriphos in all four sites with different levels. We argue this is due to heterogeneous selection pressure triggered by local treatment practices. The high levels of resistance developed to these insecticides in the four studied areas may compromise their use in mosquito control. It hence becomes urgent to find alternatives to control larval populations of Cx. pipiens in these regions.
显示更多 [+] 显示较少 [-]