AbstractThe status of insecticide resistance in field populations of eggplant fruit and shoot borer, Leucinodes orbonalis (Guenée) (Lepidoptera: Crambidae) from the major vegetable growing regions of India was determined during the cropping seasons of 2009–2010 and 2010–2011. Six commonly used insecticides: carbaryl, chlorpyriphos, deltamethrin, endosulfan, fenvalerate, and profenofos were tested against L. orbonalis larvae. The resistance ratios (RR) at the lethal dosage (LD)50 levels were estimated as RR=LD50 field strain/LD50 susceptible strain. The L. orbonalis populations exhibited widespread resistance to tested insecticides. The highest average RR in the two-year study was observed in the assays of populations with deltamethrin (21.50–82.42-fold) followed by assays conducted with endosulfan (24.47–68.26-fold), chlorpyriphos (22.17–63.14-fold), carbaryl (39.18–49.09-fold), and fenvalerate (14.00–44.66-fold); and the lowest average RRs were observed in the assays with profenofos (16.65–39.43-fold). The high levels of LD50 values can be attributed to the long-term indiscriminate use of these insecticides in eggplant (Solanum melongena Linnaeus; Solanaceae) growing regions.