Sublethal effects of Artemisia annua L. and Rosmarinus officinalis L. essential oils on life table parameters of Tetranychus urticae (Acari: Tetranychidae)

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is one of the most important agricultural pests of the world. It causes direct and indirect damage on plants which decreases in photosynthesis and crop yield. The effect of sublethal concentrations of Artemisia annua L. (Asteraceae) and Rosmarinus officinalis L. (Lamiaceae) essential oils were assessed on development and reproduction para-meters of two-spotted spider mite T. urticae. Lethal and sublethal concentrations were estimated by fumigant bioassay of essential oils on the adults of T. urticae. The raw life history data of all individuals were analyzed according to the age-stage, two-sex life table theory. LC30 and LC50 of A. annua (2.908 and 4.14 µl/80 ml air) and R. officinalis (1.339 and 2.006 µl/80 ml air) showed that rosemary essential oil has higher fumigant toxicity against T. urticae. Sublethal concentration of the two plant oils led to significant decrease in fecundity, generation time and adult longevity compare to the control. In addition, plant oils decreased the net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), and significantly increased doubling time (DT) of T. urticae in compare with control. Obtained results indicated that, sublethal concentra-tions of A. annua and R. officinalis oils could influence on biological indices of T. urticae.