The present invention relates to a pesticide nano-emulsion comprising: (a) a horticultural oil as an active ingredient； (b) a mixture of inert ingredients comprising: (i) an emulsifier； (ii) a stabilizer； and (Hi) a surfactant； and (c) a solvent, wherein the horticultural oil is dispersed as droplets in the solvent to form the nano-emulsion. Preferably, the droplets comprise an average size of 50 - 350 nm or 100 - 250 nm. In other embodiments, the mixture of inert ingredients further comprises a sticking agent or the horticultural oil may be soybean oil or palm oil. In another embodiment, the horticultural oil is in an amount of 45.0% w/w of the pesticide nano-emulsion and the mixture of inert ingredients is in a concentration of 55.0% w/w of the pesticide nano-emulsion. Preferably, the pesticide nano-emulsion is adapted to be diluted about 100 times to 800 times to form a dilute pesticide nano-emulsion, wherein the horticultural oil is in a concentration range of 0.056% to 0.45% v/v of the dilute pesticide nano-emulsion.
