Rice stem dipping method was used to test toxicity of 18 insecticides against Nilaparvata lugens(Stl).The screened pesticides with high activity were compounded to test joint toxicity and synergies against N.lugens,and determine the synergistic activity of different synergists with screened compound.The results showed that the order of the toxicity was:fipronil> buprofezin> nitenpyram> hexaflumuron>thiamethoxam>emamectin benzoate> pymetrozine> abamectin> diafenthiuron> chlorpyrifos> metolcarb> acetamiprid>...