The toxicity of essential oils of some plant species against adults of colorado potato beetle, leptinotarsa decemlineata say (Coleoptera: Chrysomelidae)

Abstract

In the present study, the essential oils obtained from 14 plant species including 5 species of Achillea, 4 species of Origanum, 3 species of Artemisia and 2 species of Thymus were tested for their toxicity against adults of Colorado potato beetle (CPB), (Leptinotarsa decemlineata Say). The bioassays were performed in laboratory conditions. After exposure, mortality of the adults was determined at 24, 48, 72 and 96 h. The majority of tested essential oils were found to be toxic to the adults of CPB. The toxicity degrees were found to be variable ranging from 2.22 to 100% mortality. Essential oils obtained from Achillea wilhelmsii, Artemisia santonicum, Achillea biserrata, Origanum acutidens and Origanum vulgare subsp. hirtum were the most effective at the end of the first 24 h in the lowest dose applications. However, at the end of the 96th h, the most effective essential oils were obtained from Achillea millefolium, Achillea biebersteinii, Artemisia absinthium, Origanum onites and Thymus sipyleus. The insecticidal effect was influenced by the doses of the essential oils and the exposure time. © 2015, Academic Publishing House. All rights reserved.