Effect of Synergist in Combination with Organophosphate against Helicoverpa armigera Hubner of Different Strain

The experiment was carried out during kharif season 2012–2013 at Insectary of Entomology Section, College of Agriculture, Nagpur. Different strain viz. Nagpur, Akola and Yavatmal of Helicoverpa armigera (Hubner) larvae was collected from unsprayed chemical field and laboratory experiment was planed in completely randomise design (CRD) with replicated in thrice and seven treatments including control viz. T₁ = Quanalphos 0.05%, T₂= Monocrotophos 0.06%, T₃ = Monocrotophos 0.06% + sesamum oil 2 ml/l, T₄ = Monocrotophos 0.06% + karanj oil 2 ml/l, T₅ = Quanalphos 0.05% + sesamum oil 2 ml/l, T₆ = Quanalphos 0.05% + karanj oil 2 ml/l and T₇ = distilled water. Application of quinalphos 0.05% + sesamum oil 2 ml/l was found better result for each strain of H. armigera (Hubner) larvae in mortality, resistance and resistance suppression of larvae. In combination of organophosphate insecticide with sesamum oil act as superior synergist as compare to karanj oil.