Comparative Study of Antioxidant Activity, Biology and Toxicity Evaluation of Three Plant Extracts against Tetranychus urticae Koch (Acari: Tetranychidae) in Comparison with Abamectin

In existing study, successive concentrations of three plant extracts (0.25 SS, 0.50 SS, 0.75 SS, and standard solution, SS) of Melia azedarach L., Duranta sp., and Datura stramonium L. as acaricides was investigated in vitro on the developmental periods of T. urticae Koch in comparison to Abamectin. The Duranta sp., M. azedarach and D. stramonium contained a considerable amount of phenolic compounds (32.22,79.33 and 65.93 mg/g) respectively, and flavonoids (12.23, 39.78 and 25.72 mg/g), thus influencing the antioxidant activity of the (Duranta, Melia and Datura), which scavenged (65% , 93% and 80%) respectively of DPPH free radicals. Results displayed that, the acaricidal effect of the plant extracts mentioned was demonstrated by the mortality percentages of TSSM. M. azedarach was the most effective extract at all tested concentrations, followed by D. stramonium and Duranta sp. in all exposure periods with the adult stages of the mite T. urticae, while Duranta sp. was the least effective. Furthermore, T. urticae raised on cucumber (Cucumis sativus L.) cultivar Toshka (SC 349) discs and treated with plant extract versus abamectin under in vitro conditions showed that abamectin was the most effective compound on the number of eggs, immature development time, longevity, life span, and life cycle of T. urticae, followed by M. azedarach, D. stramonium, and Duranta sp. We conclude that, in addition to evaluated plant extract, cucumber cultivars that are effective against TSST reproductive and biological aspects are a moral alternative control for T. urticae in protected cucumber agriculture.