2024 年 66 巻 p. 85-88
The two-spotted spider mite, Tetranychus urticae Koch, poses a critical challenge in rose cultivation owing to its reduced susceptibility to acaricides. Therefore, this study aimed to assess the efficacy of five distinct acaricides against adult female T. urticae inhabiting rose plants in 13 greenhouses located in the central region of Shizuoka Prefecture, Japan. The findings revealed substantial variations in the adjusted mortality rate of T. urticae, contingent upon the specific acaricides examined and the respective greenhouses from which they were sampled. The acaricides effectuating lower standardized fatality in T. urticae differed across the surveyed greenhouses. This observation suggested that the susceptibility of T. urticae to acarides is influenced not only by the type of acaricide used but also by the specific greenhouse environment, despite being confined to the same area.