Resistance of Rattus norvegicus to the anticoagulant rodenticides in Chengdu

Objective To Evaluate the resistance ofRattus norvegicusto warfarin and bromadiolone in Chengdu, providing information for the control of rodents in the area.Methods The resistance ofR. norvegicusto warfarin and bromadiolone was tested with the BCR method.Results The 50% effective dose (ED50) of warfarin forR. norvigicuswas 0.873 mg/kg for male and 1.439 mg/kg for female respectively, with that of bromadiolone being 1.091 mg/kg for male and 1.296 mg/kg for female. According to the baseline of susceptibleR. norvegicusapproved by ARRPC,the resistance level of the population was between 0.578 and 0.676 fold for warfarin and between 2.125 and 2.321 for bromadiolone.Conclusion R. norvigicuspopulations have developed resistance to bromadiolone in Chengdu, but not to warfarin, which can be used as an alternative rodenticide applicable to the control of rodents in Chengdu.