The invention relates to a sustained release pheromone formulation comprising a pheromone contained in a porous clay material, wherein the clay material has a weight average particle size of less than 0.2 mm, and wherein the clay material is, in one embodiment, partially coated. The invention further relates to the process of manufacturing such a formulation and its use in agriculture, as well as a method of reducing the population of a pest, e.g., a butterfly or bug such as Diabrotica virgifera in an agriculturally used area.
