biological effects of citrus peels essential oils against confused flour beetle, tribolium confusum duval (coleoptera: tenebrionidae)

in this research, fumigation efficiency, repellency and persistence of citrus essential oils extracted from dried peels of orange, bitter orange and mandarin (cultivars: satsuma, page, clemantin) were investigated against adults of confused flour beetle tribolium confusum duval. the essential oils were extracted by using clevenger apparatus. 40 ml glass container as bioassay chamber and filter paper (whatman, n˚1) as releasing source of the essential oils were used for evaluating fumigation. mortalities caused by four concentrations of the essential oils were assayed at 1, 3, 6, 9, 12 and 24 hours after treatment in fumigation effects experiments. repellency effect of four concentrations, 0.18, 0.36, 0.72 and 1.45 μl/cm2 was measured by comparing the number of adults in treated and untreated areas. an ascendant trend was observed between the concentrations and mortality in fumigation toxicity assay, but essential oils exert their efficiency in first 12 hours. highest concentrations of the essential oils (325, 400, 350, 275 and 300 μl/l air, respectively) were caused more than 97% mortality after 24 hours. the repellencies averages of the four concentrations were 32.5, 65, 55, 37.5 and 40%, respectively. the essential oils persistency were between 12 (satsuma) to 22 days (clemantin).