Roland, The concept behind diatomaceous earth is that the very fine particles are like glass shard and the critters that crawl through it have there little bodies sliced to shreds. It is most often used at the base of a plant for things that crawl onto plants. I don't think I would use this as a dust even using a dust mask because of particle drift. It would also have a tendency to wash off when watering. Because of the need for insects to walk through it, I suspect it would not be very effective with flying insects. Bob Hoel 630-279-8510