effect of fungus beauveria bassiana formulations with different vegetable oils and their chemical attraction to the pathogenesis on the sawtoothed beetle population oryzaephilus surinaemensis in terms of dates nutrition

in order to complete the microbial control of the sawthoothed beetle by the fungus beauvaria bassiana (isolate 441c) in ipm program of stored date, 9 edible and commercial vegetable oils including canola, soybean, sesame, corn, coconut, grape seed, olive, sunflower and almond were investigated to formulate the fungus. results showed that b. bassiana formulated with sesame oil was the most suitable among the oils used in this research because of the lowest lc50 with 1.491×104 spore/ml. sesame oil had also the highest synergistic effect with the quickest mortality effect and almond oil had the highest antagonistic effect on the fungus. the lowest and highest immunity coefficient of the pest population was calculated with sesame and soybean oils formulation, respectively. among the fatty acids found in vegetable oils, the margaric and arashidic acids had additive effects and the fatty acids palmoletic and linoleic had an impact effect on the pathogenesis of the fungus b. bassiana.