Abstract :
The objective of this study was conducted to determine the efficacy of five acaricides; Abamectin, Emamectin benzoate, Acequinocyl, Chlorfenapyr and Hexythiazox against Tetranychus urticae and its natural enemies, Phytoseiulus persimilis and Stethorus gilvifrons. The tested acaricides were arranged in a descending order of speed of action against T. urticae as follows: Abamectin, Emamectin benzoate, Acequinocyl, Chlorfenapyr and Hexythiazox with LT50; 1.77, 2.85, 3.16, 3.94and 4.55 days, however, the corresponding speed action index were 100.00, 62.11, 56.01, 44.92 and 38.90%, respectively. Concerning P. persimilis, Abamectin was the slowest Speed of action compared with other tested acaricides (LT50= 4.31 days) followed by Acequinocyl, Emamectin benzoate, Chlorfenapyr and Hexythiazox with LT50; 2.90, 1.78, 1.38 and 1.03 days and the corresponding speed action index of 23.90, 35.52, 57.87, 74.64 and 100.00 %, respectively. Also, Abamectin recorded the lowest Speed of action against S. gilvifrons (LT50= 4.16 days) followed by Acequinocyl, Emamectin benzoate, Hexythiazox and Chlorfenapyr with LT50; 2.81, 2.61, 1.89 and 1.85 days and the corresponding speed action index of 44.47, 65.84, 70.88, 97.88 and 100.00 %, respectively. Reviewing the obtained results, it can be noticed that Abamectin was the quickest in its action against T. urticae and the slowest against P. persimilis and S. gilvifrons compared with other tested acaricides. The efficacy of the tested acaricides on the population density of T. urticae could be arranged according to the general mean of reduction percentage in a descending order as follows: Abamectin, Acequinocyl, Hexythiazox, Emamectin benzoate and Chlorfenapyr which recorded 83.29, 66.06, 56.40, 53.02 and 25.67% reduction, respectively.
