Toxicity of essential oil vapours to two greenhouse pests, Tetranychus urticae Koch and Bemisia tabaci Genn.

Essential oil vapours from Satureja hortensis L., Ocimum basilicum L. and Thymus vulgaris L. (Lamiacae) were tested for their toxicities against the nymphs and adults of Tetranychus urticae Koch (Acari: Tetranychidae) and adults of Bemisia tabaci Genn. (Homoptera: Aleyrodidae). The amounts of essential oils applied were 1.56, 3.125, 6.25 and 12.5 mul in each of the desiccators with 41 capacity, corresponding to 0.39, 0.782, 1.563 and 3.125 mul/l air. Although desirable insecticidal and acaricidal activities against both of these pest species were achieved with essential oils of the three plant species, S. hortensis was found to be the most effective, compared with the other two species. It can be concluded that essential oils from these three plants are potential control agents against T urticae and B. tabaci in greenhouse conditions. (C) 2003 Elsevier B.V. All rights reserved.