Inheritance of resistance to esfenvalerate in Colorado potato beetles (Coleoptera: Chrysomelidae)

The inheritance of resistance to esfenvalerate in Colorado potato beetles, Leptinotarsa decemlineata (Say), was examined using quantitative genetic analysis. Selection on a held-resistant strain was conducted for 2 generations to estimate the realized heritability of esfenvalerate resistance. Bioassay data from selection experiments indicated that the resistant strain had little genetic variation in esfenvalerate susceptibility, because the resistance level was not significantly increased compared with the initial laboratory generation. The realized heritability was estimated as 0.45, indicating a moderate heritability, although it was not significant. The log LD,, value was partitioned into several components after, bioassay data of F-1 progeny from reciprocal crosses indicated that esfenvalerate resistance was inherited in a sex-linked, semirecessive fashion. Partitioning of the log LDS, value detected significant additive and dominant effects of sex chromosomal factor(s) but not autosomal factor(s). Based on the detected effects, the degree of dominance of esfenvalerate resistance was estimated as 0.262, indicating esfenvalerate resistance was semirecessive. This study confirmed that resistance to esfenvalerate in Colorado potato beetles was sex-linked, semirecessive.