The present invention relates to a new formulation characterised by the presence of two components, one of which (A) possesses insecticidal, acaricidal, fungicidal, snailcidal or vermicidal activity and the other (B) exhibits synergistic activity with the first by enhancing its effectiveness, and in which the average release time of component (A) is 1 to 12 hours later than the average release time of component (B). The formulation is obtained by: a) separate microencapsulation of both components (A) and (B) within a multilayer system of specific polymers in which component (A) is in a more interior portion of the capsule than component (B), being separated from component (B) by a polymer layer of suitable thickness (FIG. 1)； b) microencapsulation of both components within a single layer system (FIG. 2), combined with an immediate-release emulsion/microemulsion containing an additional amount of component (B).
