The invention relates to a method for crop protection comprising administering to one or both of the crop and its environment a composition comprising a carrier and microcapsules having a core material comprising a pesticide encapsulated by a silica shell, wherein the silica shell constitutes up to 10% w/w out of the total weight of the microcapsules, and wherein said administration gives rise to pesticide activity with immediate onset and prolonged effect. The invention further relates to a method for acute treatment of a pest-infested crop.