فریبا سهرابی

In attempt to find a natural and inexpensive method for control of the stored-product pests, fumigant toxicity of five medicinal plant essential oils including Trachyspermum ammi ajowan, Salvia mirzayanii Rech. var. Jam, Foeniculum vulgare Fennel, Zataria multiflora Boiss. var. Jam and Mentha piperita L. was tested against fourth instar larvae and adults of Carpophilus hemipterus (Linnaeus). Experiments were carried out at 25±1°C, 65±5% RH and under dark conditions. Essential oils were extracted using hydro distillation by a modified Clevenger-type apparatus. Mortality was evaluated at three different concentrations (ranged from 133.33 to 66.666 ?L/L air) for larvae and 5 concentrations (ranged from 13.33 to 666.66 ?L/L air) for adults at 24, 48 and 72 hour exposure time and with 3 replications. In each of the containers 10 larvae or adults were released and the desired essential oil was released on the filter paper in the inner surface of containers at different concentrations. The results showed that by increasing concentration and time, mortality rate was increased. At the highest concentration, T. ammi, S. mirzayanii, F. vulgare, Z. multiflora and M. piperita essential oils resulted in 100, 82.2, 81.1,100 and 100 percentage mortality of adults, and 85.5, 83.3, 90, 93.3 and 93.3 percentage mortality of larvae, respectively. It is concluded that the essential oils of tested plants can be used to protect stored products against this pest species.