Abstract
The genetics of resistance to cyhexatin in Tetranychus kanzawai, one of the major pests of tea plants in Japan, was investigated using homogeneously resistant and susceptible strains of the mite. Similar dosage-mortality lines obtained in the F1 progenies from reciprocal crosses indicated the absence of sex-linked inheritance. The dosage-mortality line in the F2 progeny from backcrossing the F1 hybrid to susceptible males was significantly different from that in the expected response estimated on the basis of monogenic inheritance. These results for F1 and the backcross indicate that cyhexatin resistance in T. kanzawai is due to autosomal, polyfactorial genes.