COMPARATIVE EVALUATION OF NOVEL ACARICIDES AGAINST TWO SPOTTED SPIDER MITE. TETRANYCHUS URTICAE KOCH. INFESTING CUCUMBER (CUCUMIS SATIVUS) UNDER LABORATORY AND GREEN HOUSE CONDITIONS

Abstract

Five commercially available new acaricides viz., Abamectin, Fenazaquin, Spiromesifen, Fenpyroximate and Hexythiazox were compared to a standard acaricide, Dicofol and Propargite for efficacy against the two spotted spider mite, Tetranychus urticae (koch) under laboratory and green house field conditions. In laboratory trials, all the acaricides resulted in 31.13 to 100 percent mortality with highest in Fenazaquin and Abamectin treatments during I season and 46.32 to 100 percent in II season with lowest percent mortality in Hexythiazox @ 0.75 mL/ L. No mite were found to be alive after 48h of treatment in Fenazaquin and Abamectin treatment compared to other acaricides and control, however in the treatments of Propargite, Hexythiazox, and Dicofol, lower mortality (<70 percent) was observed even 48 hrs after treatment during both the seasons. During first crop season, Fenazaquin 10EC @ 1.7mL/L and Abamectin 1.9EC @1.0 ml/L caused mortality in the range of 92.39–100 percent compared to Spiromesifen (88.87%), Fenpyroximate (70.03%), Hexythiazox (37.40-60.80%), Propargite (45.06%) and Dicofol (26.30%) where the efficacy declined on 14^th day observation. During II season observation, lower mortality of mites was recorded in standard acaricides viz., Dicofol (74.00%; 22.30%) and Propargite (81.30%; 39.24%) on 1 and 14^th day, respectively indicating that at initial period though the mortality was higher but these acaricides lost their efficacy over a period of time and may be failure in control of spider mites. Abamectin @ 0.5ml/L (89.29%; 94.55%) and 1.0ml/L (93.85%; 98.71%), Fenazaquin (97.68%; 94.33%), Spiromesifen (93.90%; 87.30%), Fenproximate (79.20%; 59.74%), Hexythiazox @ 1.25 ml/L (83.87%; 55.73%) showed higher mortality on 1^st and 14^th day, respectively and efficacy in terms of mortality was prolonged till last day observation. All the acaricides tested in both laboratory and green house conditions were proved superior over control and Abamactin and Fenazaquin were superior over other acarcides tested.