Microencapsulated pheromones (MECs) are small droplets of pheromone enclosed within polymer capsules. The capsules control the release rate of the pheromone into the surrounding environment. The capsules are small enough to be applied in the same method as used to spray insecticides. The effective field longevity of the microencapsulated pheromone formulations ranges from a few days to slightly more than a week, depending on climatic conditions, capsule size and chemical properties. Microcapsules in the pheromone formulations are usually kept above a prescribed diameter to avoid the risk of inhalation by humans.