Resistance to a mating disruptant composed of (Z)-11-tetradecenyl acetate in the smaller tea tortrix, Adoxophyes honmai (Yasuda) (Lepidoptera: Tortricidae).

Abstract

At tea fields in Shimada in Shizuoka Prefecture, a mating disruptant composed of (Z)-11-tetradecenyl acetate (trade name: Hamaki-con) had been used for controlling Adoxophyes honmai (Yasuda) annually since 1983. In 1986, four years after use of the disruptant was initiated, the disruption percentage of pheromone trap catches was 96%, and a high control effect was observed. However, from 1996 to 1998, 14 to 16 years after treatment was started, the percentages became less than 50%. When the disruptant was applied in other tea fields where it had not been previously used, the disruption percentages were over 99%. These results strongly suggest the possibility that a selection pressure caused by continuous use of the disruptant should have caused the low disruption percentage in Shimada. We propose that the phenomenon be termed “resistance” to a mating disruptant composed of (Z)-11-tetradecenyl acetate in A. honmai. When the sex pheromone blend of A. honmai, 63 : 31 : 4 : 2 mixture of (Z)-9-tetradecenyl acetate, (Z)-11-tetradecenyl acetate, (E)-11-tetradecenyl acetate and 10-methyldodecyl acetate (4-component blend), was applied as a disruptant for the “resistance” population, the disruption percentage was 99% and the larval density in the next generation decreased. These results suggest that the 4-component blend is useful as a control tool for the “resistance” population.