susceptibility of colorado potato beetle, leptinotarsa decemlineata (say) (col: chrysomelidae), to essential oil and main components of some medicinal plants

colorado potato beetle, leptinotarsa decemlineata (say), is one of the most important pests of potato in iran and worlds. for controlling this pest chemical pesticides have used more that have happened pollution of environment and resistance varieties. in this way, using plant materials is one of promising method for controlling this pest. in this study, essential oils of six plant species including: satureja khuzistanica jamzad, ocimum basilicum l., thymus daenensis celak., myrtus communis l., mentha spicata l. and eugenia caryophyllus (sprengel) and two monoterpenes (carvacrol and thymol) were investigated against first, second and third instars larvae and oviposition deterrence of l. decemlineata at 25±1ºc, 65±5 % rh in 16:8 conditions. result showed that when increased larval stages the effect of essential oils decreased and essential oil of s. khuzistanica and carvacrol its main component had highest effect on larval stages of colorado potato beetle. also, essential oil of s. khuzistanica had highest and o. basilicum had lowest effect on oviposition deterrence. so, essential oil of s. khuzistanica and carvacrol because of their satisfied insecticides could be used in control management of l. decemlineata for elimination of chemical toxin.