Susceptibility and repellency of Culicoides imicola and Culex pipiens to lambda-cyhalothrin.

The basic efficacy of lambda-cyhalothrin was tested in the laboratory against newly colonised adult Culex pipiens and field-collected Culicoides imicola. C. imicola was found to be more susceptible (LD(50)=0.0098%) than Cx. pipiens (LD=0.0233%); the efficacy against both species was definitely higher than that of cyhalothrin. Lambda-cyhalothrin showed slight repellency for C. imicola during the first hour post application.