Abstract
Plants are a prospective source of novel natural insect repellents and botanical insecticides. This study was conducted to investigate the chemical composition of the essential oils of three plants growing in Saudi Arabia, namely Ducrosia anethifolia, Achillea fragrantissima, and Teucrium polium; and to evaluate their potential mosquitocidal and repellent activities against adult female Culex pipiens L. The main components of the three oils were found to be decanal (28.9%) and chrysanthenyl acetate (10.04%), (D. anethifolia); sabinyl acetate (35.79) and artemesia ketone (18.28%) (A. fragrantissima); alpha-cadinol (49.53%) and delta-cadinene (10.23%) (T. polium). The oil of A. fragrantissima was the most toxic (LC50 = 0.11 mu L/L air) followed by D. anethifolia and T. polium with LC50 values of 5.22 and 25.98 mu L/L air, respectively. T. polium oil was the most repellent (292 min at 2 mu L/cm(2)), followed by D. anethifolia and A. fragrantissima. The results indicate that the essential oils have a potential fumigant insecticidal and repellent activities for mosquito control.