The Synergists Action of Piperonyl Butoxide on Toxicity of Certain Insecticides Applied Against Helopeltis Theivora Waterhouse (Heteroptera: Miridae) in the Dooars Tea Plantations of North Bengal, India

The Synergists Action of Piperonyl Butoxide on Toxicity of Certain Insecticides Applied AgainstHelopeltis TheivoraWaterhouse (Heteroptera: Miridae) in the Dooars Tea Plantations of North Bengal, India Higher efficacy of mixture of insecticides with synergists piperonyl butoxide (PB) was reported in controlling in the Dooars population ofHelopeltis theivoraWaterhouse. Therefore, the use of synergists as one of the countermeasures against the insecticide resistance problem ofH. theivorais recommended. The combination of deltamethrin +PB (piperonyl butoxide), quinalphos +PB and imidacloprid +PB showed 44.60, 16.01 and 11.14 folds increase of toxicity (synergistic ratio) than the respective insecticide alone. Piperonyl butoxide acted as an oxidase inhibitor. The addition of PB to some extent suppressed the resistance ofH. theivorato these insecticides, suggesting that the P450 enzyme complex may be involved in the mechanism of toxicity.