Maryam Negahban - Agricultural Research Education and Extention Organization, Iranian Research Institute of Plant Protection, Pesticide Research Department, Tehran, Iran
Elham Shahinfar - Department of Plant Protection, Science and Research Branch, Islamic Azad University, Tehran, Iran
Ahmad Heydari - Agricultural Research Education and Extention Organization, Iranian Research Institute of Plant Protection, Pesticide Research Department, Tehran, Iran
Sohrab Imani - Department of Plant Protection, Science and Research Branch, Islamic Azad University, Tehran, Iran

Nowadays the increased pest resistance to chemical pesticides and the pesticides residues in food, together with the toxic effects of pesticides on mammals and the environment, necessitates the use of newer and safer alternatives for controlling insect pests. The use of encapsulation technology for pesticides formulation has led to increase efficiency and control release of these substances. In this study, bio formulations, containing Artemisia sieberi Besser essential oil based on biodegradable polymers such as polyethylene glycol, starch and maltodextrin were prepared as powder and pellet. These formulations are different in the amount and type of polymers and surfactants. Also, these formulations are combined with a different rotation speed of the homogenizer. In this study, fumigant toxicity of these formulations was compared with the ordinary essential oil. The experiments were carried out on adult stage of rice weevil at ۲۷ ± ۱ ° C, ۷۰ ± ۵ % RH and in total darkness condition. The results showed that the LC۵۰ of the essential oil after ۷۲ hours was ۱۱.۲۴ ppm, while the LC۵۰ of formulations ۱ to ۴ were ۴۷.۶۱, ۵۷.۵۵, ۲۳.۹۴ and ۴۴.۶۶ ppm, respectively. Therefore, the encapsulation of plant essential oils as a safe pesticide with slow release and fumigant toxicity can be used in stock pest managements

Sitophilus oryzae, essential oil, encapsulation, Artemisia sieberi, fumigant toxicity