Monitoring insecticide resistance in Leucinodes orbonalis (Guen)

Monitoring insecticide resistance in Brinjal shoot and fruit borer Leucinodes orbonalis collected from different location of Vidarbha was determined by using direct spray method. Efforts were also made to study the LC50 values of newer insecticides and monitoring resistance of Brinjal shoot and fruit borer Leucinodes orbonalis. Five insecticides viz. Rynaxypyr 20 SC, Flubendiamide 480 SC, Emamectin benzoate 5 SG, Indoxacarb 14.5 SC and Spinosad 45 SC were tested for their toxicity to third instar larvae of Leucinodes orbonalis (Guen.). The LC50 values obtained were 0.104, 9.080, 0.214, 0.867 and 1.523 ppm for Rynaxypyr, Flubendiamide, Emamectin benzoate, Indoxacarb and Spinosad respectively. The LC50 values for field strain were Rynaxypyr (0.127 to 0.157 ppm), Flubendiamide (15.551 to 23.046 ppm), Emamectin benzoate (0.277 to 0.351 ppm), Indoxacarb (2.016 to 2.457), Spinosad (3.094 to 4.940 ppm). Akola, Amravati and Yavatmal strains showed high level of insecticide resistance than Buldhana and Washim strains of L. orbonalis. Rynaxypyr 20 EC and Emamectin benzoate 5 SG were found to be most effective amongst the insecticides tested. Thus, Rynaxypyr and Emamectin benzoate could be used to delay the development of insecticide resistance.