many many weeks...basically until the end of rainy season in november or so. eventually it got so bad that the town would fog, but that was only when the truck was working. i hate to tell ya, it gets really bad. but then again, i live south, and i chose mosquito coast. like everything in life, there are good and bad.
seriously, there is a reason i buy a dozen bottles at a time of this Sawyer stuff. It doesnt smell, its oily versus sticky so it works like a charm on the sand fleas, and its in a spray pump so no aerosol.
wish i could give you hope, but we are now coming into rainy season, and sadly, mosquitos are a part of life. a pain in the ass, make ya miserable and barricade yourself in your house part of life, but a part of life nonetheless.