Abstract

In order to determine the bio-efficacy of new acaricide molecule, etoxazole 10% SC (w/w) was tested against tea red spider mite. The experiment was conducted at Kamalpur Tea Estate, Darjeeling, West Bengal during pre-kharif and post-kharif seasons of 2011–12. Experiment was laid out in a randomized block design (RBD) with three replications for each of the treatment on standing tea bushes of 10 years old. Four doses each of etoxazole 10% SC (w/w) (10, 25, 40 and 55 g a. i./ha) along with single dose of fenpropathrin 30% EC (60 g a. i./ha), hexithiazox 5.45% EC (25 g a. i./ha) and propergite 57% EC (570 g a.i./ha) were sprayed with an untreated check to work out their efficacy against the mite. To find out the phytotoxic effects of the above insecticides, a higher dose of etoxazole 10% SC (w/w) at 80 g a. i./ha was included. Two rounds of spraying were done at an interval of 45 days during both the seasons. Observations were taken before spraying as pre-treatment count on mean mite population/cm2 leaf area and thereafter mite population was counted at 1, 3, 7 and 15 days after each spraying. The treatments etoxazole 10% SC (w/w) @ 40, 55 and 80 g a. i./ha were at par with each other and were very effective especially in controlling eggs and immature stages of tea red spider mites and recorded higher yield of tea than rest of the treatments. In addition, no phytotoxic effect was observed even at the highest doses of etoxazole 10% SC (w/w) @ 80 g a. i./ha. No detrimental effect was noticed for application of different doses of etoxazole on the prevalent predatory mite species, Typhlodromips syzygii, whereas high mortality was recorded from propergite and fenpropathrin treated plots.