A method of controlling a target pest is disclosed that comprises providing a microemulsion pesticide formulation comprising an active pest control ingredient and a microemulsifying agent, wherein the microemulsifying agent comprises a mixture of unsaturated C12-C26 fatty acids and/or salts thereof and saturated C6-C14 fatty acids and/or salts thereof, and the active pest control ingredient comprises two or more compounds that act synergistically to control the target pest； and applying an effective amount of the microemulsion pesticide formulation to the target pest or to a surface associated with the target pest. The active pest control ingredient and the microemulsifying agent may act synergistically in the method to control the target pest. The control exhibited by the formulation may be knockdown, kill, or repellency. The method may involve long-term residual effects.
