Abstract
Spodoptera litura is an economic pest of different field crops including cauliflower. In the present study three commercial formulations of biorational insecticides viz., Bacillus thuringiensis (DiPel (R)), NPV (SpltNPV) and Flubendiamide (Belt (R)) evaluated (alone and in combination) against S. litura under field condition. Minimum plant infestation (7.60 +/- 0.40%) was observed three days after application when B. thuringiensis and flubendiamide were applied in combination (@0.5 kg/ha+75ml/ha, respectively). Maximum infestation (11.60 +/- 0.97%) was observed in SpltNPV @ 1.0x10(9) POB/ml + B. thuringiensis @ 1.00 kg/ha. Similarly, five days after application minimum plant infestation was observed in B. thuringiensis and flubendiamide @0.5 kg/ha+75ml/ha (5.20 +/- 0.49%) and maximum in SpltNPV @ 1.0x10(9) POB/ml + B. thuringiensis @ 1.00 kg/ha (8.80 +/- 0.49%). Whereas, minimum plant infestation was observed seven days after application where B. thuringiensis and flubendiamide were applied in combination @ 0.5 kg/ha+75ml/ha i.e. 2.80 +/- 0.49 % followed by B. thuringiensis @ 1.0 kg/ha + flubendiamide 480 SC @ 75ml/ha, SpltNPV @ 1.0x10(9) POB/ml + B. thuringiensis @ 0.5 kg/ha, SpltNPV @ 1.0x10(9) POB/ml + flubendiamide 480 SC @ 75ml/ha and SpltNPV @ 1.0x10(9) POB/ml + B. thuringiensis @ 1.00 kg/ha i.e. 4.00 +/- 0.63, 4.40 +/- 0.40, 4.80 +/- 0.48 and 5.60 +/- 0.40 %, respectively. Whereas, B. thuringiensis @ 1.0 kg/ha, flubendiamide @ 75ml/ha, SpltNPV @ 1.0x10(9) POB/ml and B. thuringiensis @ 0.5 kg/ha were gave plant infestation 6.40 +/- 0.40, 6.80 +/- 0.49, 8.80 +/- 0.48 and 9.20 +/- 0.49%, respectively. After second application, lowest plant infestation was recorded in the plot treated with B. thuringiensis @ 0.5 kg/ha+flubendiamide 480SC @ 75ml/ha with plant infestation of 8.40 +/- 0.40, 5.60 +/- 0.40 and 2.20 +/- 0.40 % at three, five and seven days after application, respectively. However, all the insecticides reduced natural enemies (Chrysoperla carnea, ladybird beetles, and predatory bugs) populations in all the treatments. In conclusion, the results revealed the potential of Bt, NPV and flubendiamide for the management of S. litura. Further studies are needed to confirm the potential of these products against S. litura and negative impact on natural enemies under varying climatic conditions, and on different host crops.