Lethal and Residual Effects of Lambdacyhalothrin, Deltamethrin and Cyfluthrin Insecticides on Adult Mosquitoes of Anopheles stephensi Liston(Diptera: Culicidae) on Different Surfaces

Background: human malaria remains a major malady in easterniran. vector control interventions such as indoor residual sprayingare used to fight with the disease. this study was undertakento determine the lethal and residual effects of three differentpyrethroid insecticides on adult mosquitoes of anophelesstephensi on different surfaces in iran, as part of a nationalprogram to monitor insecticide resistance in endemic areas.methods: two main endemic foci were selected as collectionsites. wild adult females of an. stephensi (mysoriensis strain)from the first focus were subjected to standard susceptibilitytests, using lambdacyhalothrin, deltamethrin and cyfluthrininsecticides within holding tubes according to the methodproposed by who. in kazerun, the residual effects of thesecompounds were examined by conical bioassay tests of an.stephensi (type strain) on plaster and cement walls. data wereanalyzed using mann-whitney test to determine the differencesin susceptibility and residual effects of an. stephensi mosquitoesto these insecticides.results: the susceptibility of females of an. stephensi tothree concentrations of lambdacyhalothrin, deltamethrin andcyfluthrin insecticides culminated in full scale mortality at thehighest diagnostic dose. the maximal residual time of these threeinsecticides on plaster and cement walls was estimated to be aboutthree months. there was no significant difference in the mortalitiesof an. stephensi on different sprayed surfaces (p=0.653).conclusion: all field-collected an. stephensi populations exhibitgross susceptibility to all diagnostic doses of the three evaluatedinsecticides. in endemic areas, lambdacyhalothrin reveals aslightly longer residual activity than the other two insecticides.