The first example of resistance to a mating disruptant was reported in the smaller tea tortrix moth, Adoxophyes honmai. The active ingredient in the disruptant was (Z)-11-tetradecenyl acetate (Z11-14:OAc), which is one component of the sex pheromone of A. honmai. From a resistant colony in the field, a strain highly resistant to mating disruption was established through further selection imposed in the laboratory by rearing in the presence of Z11-14:OAc. With this resistant (R) strain, we investigated the response of males to mixtures of synthetic pheromone components in the present study. Males of the R strain were less attracted to a low concentration of the pheromone than non-resistant (S) males. However, the R males were attracted to lures with extremely deviated ratios of the pheromone components: 72% of them even responded to the mixture lacking Z11-14:OAc, which is indispensable for response behavior of the S males. Some F₁ males of crosses between S and R (13–15%) and male progeny in both reciprocal backcrosses to R (29–38%) were also attracted to the mixture without Z11-14:OAc. The results of these crossing experiments could be seen corresponding with the expected pattern in a single-autosomal-locus model for inheritance of the ability to respond to a defective pheromone blend.