The present invention relates to microcapsules comprising a polyurea shell and a core, which contains a pesticide, a water-immiscible solvent A and at least 5 wt % of an aprotic, polar solvent B, which has a solubility in water from 0.5 to 20 g/l at 20° C., based on the total weight of the solvents in the core. It further relates to microcapsules comprising a shell and a core, which contains a pesticide and 2-heptanone; to a method for preparing said mircocapsules; to an aqueous composition comprising said microcapsules; and to a method for controlling phytopathogenic fungi and/or undesired plant growth and/or undesired attack by insects or mites and/or for regulating the growth of plants, with said mircocapsules.