Abstract
The efficacy of three pyrethroid insecticides (lambda-cyhalothrin, deltamethrin, and cyphenothrin) in cold (CF) and thermal fogging (TF) applications against caged adults of Culex pipiens Linnaeus were evaluated under hot-dry conditions in Riyadh, Saudi Arabia. The efficacy of CF and TF at different distances from the release point (15, 30, 45, and 60 m) and height (1 and 2 m) was also investigated by evaluating adult mortality after 24 h of exposure. Our data indicated that TF was more efficacious than CF. While the distance from the spray path did not affect TF efficacy, CF showed decreased efficacy with the increase in distance from the spray path. Deltamethrin efficacy was significantly affected by both the application method and distance from the spray path, whereas lambda-cyhalothrin was only affected by the spray method.