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Efforts were made to study the LC 50 values of newer insecticide against brinjal shoot and fruit borer (Leucinodes orbonalis) collected from different location of Vidarbha viz., Akola, Amravati, Yavatmal, Washim and Buldhana by using direct spray method carried out in the toxicology laboratory, Department of Agricultural Entomology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola during 2011-12. 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 resultant toxicity in terms of LC 50 values obtained for insecticide against different strain were ranged for rynaxypyr (0.127-0.157), flubendiamide (15.551-23.046), emamectin benzoate (0.277-0.351), indoxacarb (2.016-2.457) and spinosad (3.094-4.940) ppm. Rynaxypyr 20 EC and emamectin benzoate 5 SG were found most effective amongst the insecticides tested. Thus, rynaxypyr and emamectin benzoate could be used for management of Leucinodes orbonalis and to delay the development of insecticide resistance.

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The present investigation was conducted during <italic>kharif</italic> 2011-12 on field of Department of Agricultural Entomology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. The experiment was planned in randomized block design with gross plot size 4.2 x 4.4 m² and net plot size 3.0 x 4.0 m² with twelve treatments replicated thrice with the object to study the effect of some insecticides against pigeonpea pod fly, <italic>Melanagromyza obtuse</italic>. In evaluation studyten treatments were tested against pod fly, <italic>Melanagromyza obtuse</italic>. on pigeonpea. The result revealed that treatment Deltamethrin 1 EC + Triazophos 35 EC emerged as the most effective treatment against <italic>M. obtusa</italic> in minimizing the damage to green and drypods as well as grains. Thiaclopride 21.7 SC and Profenophos 50 EC were found significantly effective in minimizing the cumulative mean per cent infestation of pod flyof pigeonpea. These findings indicate that the pigeonpea crop required two sprays of newer insecticides from pod initiation stage at 15 days interval for the management of pigeonpea pod fly, <italic>Melanagromyza obtusa.</italic>

90 within range of 6.413 to 18.349 ppm. The resistance level is visibly high in cypermethrin, moderate to indoxacarb, quinalphos, spinosad and low to methomyl; Yavatmal and Washim strains expressed higher resistance level to cypermethrin, quinalphos and methomyl, whereas Yavatmal and Buldhana strains expressed higher resistance level to indoxacarb and spinosad. The investigation will help to track resistence level in Helicoverpa armigera to different groups of insecticides.