Fumigant Toxicity of Rue Essential Oil, Ruta Graveolens L. on Tetranychus Urticae Koch (Acari: Tetranychidae)

Abstract

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is one of the most important pests affecting agricultural and ornamental crops worldwide. In fact many of natural plant (bioactive compounds) have fewer side effects compared with chemical pesticides. So, this study aimed to evaluate the effect of rue leaves essential oil, Ruta graveolens L. as fumigant toxicity (Sapindales: Rutaceae) against eggs and adult females of T. urticae. Gas chromatography–mass spectrometry (GC-MS) data cleared that the basic constituents were 2-undecanone (60.54%) and 2-nonaone (17.71%) which belonged to methyl ketones that represented by 81.65% of the total oil. The ovicidal activity of rue essential oil mentioned that according to LC50 values, the one-day-old eggs were more susceptible than three -days-old eggs recording 0.008 and 0.011 µl/ml air after 7 days post fumigant for 24 h, respectively. Furthermore, the adult female mortality recorded 0.018 and 0.0724 µl/ml air for LC50 and LC90, respectively. Additionally, results demonstrated that significant reduction in the mean number of deposited eggs/female/day recorded 3.182 eggs compared to 6.561 eggs for control. Finally, a significant reduction in acid phosphatase for eggs and Aacetylcholine esterase (AChE) for adults of T. urticae were recorded.