Inheritance of chlorpyrifos resistance in culex pipiens L. (diptera: Culicidae) and estimation of the number of genes involved

Abstract

The inheritance of chlorpyrifos resistance has been studied in a strain (MSE) derived from larvae collected in southern France in 1979, using two susceptible strains (S-LAB and YPL). All FI offspring displayed straight dosage-mortality (ldp) lines confirming that the susceptible and the resistant strains were homozygous for the genes involved. All backcross ldp lines differed significantly from those expected if resistance had been monofactorial and were straight regression lines. Based on the crosses involving the S-LAB strain, the number of additive and independent genes contributing to chlorpyrifos resistance was estimated to be at least 2 and perhaps more. The evolution of chlorpyrifos resistance in natural populations in southern France is discussed in the light of these findings. © 1987, The Genetical Society of Great Britain.