Effectiveness of IPM strategies against eggplant shoot and fruit borer Leucinodes orbonalis (Lepidoptera: Crambidae)

Leucinodes orbonalis (Guenee) inflicts considerable damage on eggplant. In the present study farmers’ practice (Regime 1: Repeated use of different insecticides viz., Cypermethrin, Monocrotophos, Chlorpyriphos and Triazophos once or twice at weekly intervals) was compared with two IPM regimes, during 2010-12. The IPM regimes were: 1) Regime 2: weekly shoot clipping of infested twigs at the time of infestation along with installation of pheromone traps at 100/ha (lure was changed at 25 days intervals); and 2) Regime 3: weekly shoot clipping of infested twigs at the time of infestation along with installation of pheromone traps at 100/ha (lure was changed at 25 days interval) and need based application of NSKE at 4% and cartap hydrochloride at 1 g/l. The least fruit damage (20.46%) was observed in regime 3. With this IPM regime, the fruit damage was prevented by 35.01 to 36.18% and 22.87 to 23.33% additional yield was recorded over the regime relied upon only chemical pesticides. An additional income of USD $ 1064.22/ha was also obtained in open pollinated and USD $ 1799.35/ha in hybrid cultivars with a 10 to 11 times reduction of chemical sprayings in the regime 3. The selected regime not only reduced the total cost of crop production but also increased the net return per unit area. The IPM programme (regime 3) that consisted of cultural, mechanical and chemical components was proved to be an ideal management strategy against eggplant shoot and fruit borer along with a benefit: cost ratio of 3.65 to 4.27.