Efficacy of various insecticides against castor hairy caterpillar (Euproctis lunata Walker) on castor

The present study was undertaken to find out certain effective insecticides against castor hairy caterpillar. All the insecticides proved better than the control at all the intervals of observations. The effectiveness of the insecticides increased with time interval after spraying. The results after seven days of treatment revealed that larval mortality ranged from 63.41 to 82.92 per cent. Maximum population was recorded (8.2 larvae per plant) in control. The best results were recorded in novaluron 10 EC (0.01%)-treated plot (1.4 larvae/plant) with 82.92 per cent mortality in the larval population followed by novaluron 10 EC (0.007%) (1.6 larvae/plant) with 80.48 per cent mortality and cypermethrin 25 EC (0.018%) (2.0 larvae/plant) with 75.60 per cent mortality over control. The highest yield 2660 kg/ha was recorded under treatment novaluron 10 EC (0.01%) which was 510 kg more than the control. Other treatments gave additional yield varying from 220 to 450 kg. However highest monetary return in the present study was obtained under the treatment of cypermethrin 25 EC (0.018%) (B-C ratio 21.93: 1) followed by cypermethrin 25 EC (0.0125) (B-C ratio 21.10: 1) and quinalphos 25 EC (0.075%) (B-C ratio 10.6: 1).