The Barrier Spray from NJ Mosquito Patrol can keep mosquitoes away for up to 14 days. The effects are nearly instantaneous. Our spray destroys adult mosquitoes and ticks within just 24 hours of application and will remain on the foliage around your yard for up to two weeks. Mosquitoes from other areas, including your next-door neighbors, will be destroyed if they attempt to feed, breed, or land on your treated vegetation.