author(s)
Kapil Kumar Bhuyan, Gautam Kumar Saikia, Mukul Kumar Deka, Bithika Phukan and Subhash Chandra Barua

abstract
Fish extract at 0.25, 0.5 and 1%, Polygonum hydropiper at 2.5, 5 and 7.5% and Azadirachtin-5% (Neemazal-F) were evaluated in the laboratory against red spider mite, Oligonychus coffeae (Nietner) to determine its effect on viability of eggs and mortality of adult and nymphs mites. The result showed that highest reduction in hatchability of eggs of red spider mite was achieved by Fish extract 1% followed by Polygonum hydropiper extract 7.5% in both the periods of study. Both fish extract 1% and Polygonum hydropiper extract 7.5% caused significant mortality on nymphs of red spider mite. The potency of both fish extract 1% and Polygonum hydropiper extract 7.5% were observed on adult mortality of red spider mite upto the extent of 81-85%. Highest reduction in hatchability of eggs, mortality on nymphs and adults was achieved by fish extract followed by P. hydropiper extract.