Abstract: Plant essential oils have proved their insecticidal potential against various insect species. They were successfully implemented mainly against stored product pests. However, constraints relating to their volatility, potential for oxidation and poor water solubility, need to be addressed before they can be considered for industrial use. Consequently, encapsulation in nanometric particles is an alternative for overcoming these problems, to modulate the release, guarantee protection of essential oils compounds against degradation or evaporation, decrease the volatility, enhance the bioactivity and reduce the toxicity.In this work, we assess the fumigant toxicity of Rosmarinus officinalis (L.) essential oils in comparison with a powdered cyclodextrin (CD)/1,8-cineole inclusion complex, a powdered 1,8 cineole in -CD- in liposome and free 1,8-cineole (oils major compound) against last instars larvae of Ectomyelois ceratoniae (Zeller) developing inside fruit. E. ceratoniae is the most important and destructive insect pest attacking dates in Tunisia. It caused loss of weight and downgrading of the commercial value of dates.Results revealed the performance of the nanometric particles in terms of insect mortality and toxicity persistence. Results emphasized the benefit of essential oils encapsulation either in cyclodextrin or in liposomes for the postharvest control the date moth E. ceratoniae.