I'm spraying malathion because I have a bad infestation of Tomato Fruitworm. (corn earworm) They have destroyed about 80% of my tomatoes.
I have since learned that there is a better insecticide for this critter, but malathion was the only insecticide the local Walmart had. (Walmart is the only local store.)
I still have some of what looks like early blight on the tomatoes, but since the worm is the biggest problem, I don't want to wash off the insecticide before it can do it's job.