Preparation of nanoemulsion formulation of essential oil of Zataria multiflora and comparison of contact toxicity with pure essential oil on Ephestia kuehniella

In recent decades, providing new formulations of botanical insecticide as a replacement for synthetic pesticides is taken in to consideration. Essential oils have been used as pesticides in last decades, but essential oils have many restrictions on their use such as voltality, rapid oxidation and chemical instability in the prescence of light, moisture and high temperature. In order to increase the efficiency of essential oils, the use of formulations with controlled release of the oil encapsulated in micro- and nano-scales would be the best option.In this research ,after making a new nanoemulsion formulations ofessential oil of Zataria multiflora, contact toxicityof the essential oil before and after nanoemulsion was evaluated on reared Ephestia kuehniella at 27±1°C and 65±5% RH under dark conditions.Nanoemulsion essential oil was carried out by the method of gum - maltodextrin using homogenization and morphology and size were determined by TEM .In contact toxicity test, the LC50 values of pure and nanoemulsion essential oil of Zataria.multiflora on larvae after 72hours ,were 0.61 and 0.15 µl/cm² respectively. Therefore the toxicity of nanoemulsion essential oil of Zataria.multiflora was 4.32 folds higher than the pure essential oil. Findings led to a conclusion that encapsulated thechnology of essential oils can enhance their control release and persistence under controlled condition.