Effect of essential oil of some plants on feeding and oviposition behaviors of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Col.: Chrysomelidae)

Colorado potato beetle، Leptinotarsa decemlineata (Say)، is a serious pest of potato in the Ardabil. In this study، the repellent and antifeedant effects of essential oil of five plants Teucrium polium L. Pelargonium roseum Andr، Artemisia sieberi Besser، Artemisia dracunculus L. and Citrus limonium Risso on the adult and third instar larvae of the beetle were investigated in a greenhouse under 24±1oC، 50±5 RH and 16:8 h (L: D) in 2009. In a free choice assay the lowest number of adult females was estabilished on plants treated with the concentration of 500 ml/l of T. polium and A. dracunculus. The lowest number of eggs was laid on plants treated with concentrations of 500 ml/l of T. polium. Treating the potato leaves with the concentrations of 500 ml/l essential oil of A. sieberi، C. limonium، P. roseum and T. polium resulted in the settling of the lowest number of the third instar larvae on the leaves compared with other treatments. The lowest mean relative growth rate of the third instar larvae was seen in potato leaves treated with the concentrations of 500 ml/l of essential oil of C. limonium and P. roseum. It can be concluded that the essential oils of A. sieberi، A. dracunculus and T. polium have repellant effect on adult and the essential oils of A. sieberi، C. limonium، T. polium and P. roseum have repellant effect on third instar larvae of Colorado potato beetle. Based on these results it can be concluded that the essential oils of T. polium had highest effect in IPM of the Colorado potato beetle.