ارزیابی اثر رهاسازی کنترل شده نانواسانس‌های پرتقال و نارنگی بر سمیت تدخینی آن‌ها علیه شپشه آرد Tribolium confusum (Col.: Tenebrinoidea) و شپشه برنج Sitophilus oryzae (Col: Curculionidae)

Nanoemulsion formulation has been one of the most effective types of formulation to achieve controlled release of essential oils. In this study, in order to show the effect of controlled release, fumigant toxicity of essential oils and nanoemulsions of orange and tangerine peels were investigated on two stored product pests, T. confusum and S. oryzae, in 24 and 48 hours. The essential oils were extracted from dried orange and tangerine peels using a hydrodistillation method and their content were analyzed by gas chromatography mass spectrometry (GC-MS). Ultrasonic probe sonicator (UPS) was utilized to convert the essential oil particles into the nanometer scale. Particle sizes were determined using a dynamic light scattering (DLS) instrument and was 65 nanometer for both of them. Based on preliminary experiments, eight concentrations (5, 10, 15, 20, 25, 50, 75, and 95 microliters) of the essential oils and nanoformulations were prepared for fumigant toxicity evaluation. The bioassays were conducted under controlled conditions at a temperature of 27±1 C◦, relative humidity of 65±5%, and with three independent replicates at 24 and 48 hours. Fumigant toxicity of the essential oils was higher at 24 hours, while the nanoemulsions exhibited greater efficacy at 48 hours. The highest observed mortality percentage was recorded for orange nanoemulsion at 48 hours and a concentration of 95 µl. Results showed higher efficiency of nanoemulsions in 48 h; while, they were less efficient than non-formulated essential oils in 24 h that is related to their better release function.