Abstract: A method for controlling mosquito populations comprising the following steps: a) providing an insecticide comprising a pyrethroid, b) providing a sprayer having an extension thereon, c) inserting the insecticide into the sprayer, d) inserting the extension into the catch basin, e) spraying the insecticide onto the interior surfaces of the catch basin, including any stagnant water which may be located at the drop-off of the catch basin.