اثرات سه اسانس گياهي روي فعاليت هاي زيستي سوسك چهارنقطه اي حبوبات

Effects of Three Plant Essential Oils on Biological Activity of Callosobruchus maculatus F. (Coleoptera: Bruchidae)

In search of alternatives for conventional pesticides, plant essential oils have been widely investigated. Effects of essential oils of Artemisia aucheri Boiss (Asteraceae), Salvia bracteata L. (Lamiaceae) and Nepeta cataria L. (Lamiaceae) were tested against first instar larvae, egg hatching and oviposition rate of Callosobrochus maculatus F. Experiment was carried out at 30 ± 2 °C and 60 ± 5% R. H. under dark condition adopting a complete randomized block design. For each essential oil, six concentrations with six replications were tested. Increasing the essential oil concentration increased the effects of essential oils on eggs; first instar larvae and oviposition rate. The maximum concentration of essential oils (0.56 µl/cm^3) of A. aucheri, S. bracteata and N cataria caused, 100, 91.66 and 95% mortality of eggs and 100, 98.33 and 96.66% mortality of first instar larvae, respectively. All the three tested plant essential oils reduced the oviposition rate of adults significantly. The highest concentration (0.37 µl/cm^3) of essential oils of A. aucheri, S. bracteata and N. cataria lead to ovipositin deterrency, with a deterrence of 100, 96.78 and 97.14%, respectively. LC50 values indicated that essential oil of A. aucheri with 0.055 and 0.042 µl/cm^3 against eggs and first instar larvae was more effective than the essential oil in other plant species. It was found that plant essential oils particulary A. aucheri could be used as either a safe pesticide or model for new synthetic pesticides to control store pests.