EGYPTIAN JOURNAL OF BIOLOGICAL PEST CONTROL, cilt.23, sa.2, ss.241-246, 2013 (SCI-Expanded)
Essential oils obtained from fifteen different plant species (Achillea biserrata M. Bieb., Achillea coarctata Poir., Achillea gypsicola Hub-Mor., Achillea wilhemsii C. Koch, Artemisia santonicum L., Hypericum perforatum L., Melilotus officinalis (L.) Lam., Origanum acutidens (Hand.-Mazz), Origanum onites L., Origanum rotundifolium L., Origanum syriacum L., Satureja hortensis L., Satureja spicigera (C. Koch)., Salvia nemorosa L., and Tanacetum agrophyllum (L.) C. Koch were tested against adults of Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). Obtained results showed that the tested essential oils isolated from all plant species, except that from S. nemorosa had significant insecticidal effects against S. zeamais adults, compared with the control. Mortality rate of S. zeamais adults increased significantly (p < 0.01), as the concentration (mu l/L air) level and/or exposure time increased. Treatments with the essential oils of A. coarctata, A. gypsicola, O. onites, S. hortensis, and S. spicigera showed highest percentages of adult mortalities, when they were applied at the high concentrations (10 & 20 mu l/L air) and at all the post treatment periods or at a moderate concentration (5 mu l/L air) with long exposure periods (48 or 96 hs). The essential oil of S. nemorosa had lowest effect. After 96 h of exposure, at the maximum concentration (20 mu l/L air essential oil) of A. biserrata, A. coarctata, A. gypsicola, A. santonicum, H. perforatum, M officinalis, O. onites, O. rotundifolium, S. hortensis, S. spicigera, T. agrophyllum recorded 100% mortality, while O. syriacum, O. acutidens, A. wilhemsii, and S. nemorosa attained 99-76.77 mortality. After 96 h of treatment, 100% mortality was achieved at the concentration of 5 mu l/L air essential oil of A. gypsicola. Essential oils of M officinalis, H. perforatum, and O. rotundifolium possessed the most effective fumigant toxicity against S. zeamais adults, with LC50 values of 0.289, 0.526, and 0.573 mu l/L air, respectively.