Kluwer Academic/Plenum Acta Medica Okayama 00018244 49 5 2019 Arousal from Tonic Immobility by Vibration Stimulus 478 483 EN Takahisa Miyatake Department of Evolutionary Ecology, Graduate School of Environmental and Life ScienceOkayama University Kentarou Matsumura Department of Evolutionary Ecology, Graduate School of Environmental and Life ScienceOkayama University Ryota Kitayama Department of Evolutionary Ecology, Graduate School of Environmental and Life ScienceOkayama University Keiichi Otsuki Faculty of Computer Science and Engineering Kyoto Sangyo University Yuhao Ji Department of Evolutionary Ecology, Graduate School of Environmental and Life ScienceOkayama University Ryusuke Fujisawa School of Computer Science and Systems EngineeringKyushu Institute of Technology Naohisa Nagaya Faculty of Computer Science and Engineering Kyoto Sangyo University Tonic immobility (TI) is an effective anti-predator strategy. However, long immobility status on the ground increases the risk of being eaten by predators, and thus insects must rouse themselves when appropriate stimulation is provided. Here, the strength of vibration causing arousal from the state of TI was examined in strains artificially selected for longer duration of TI (L-strains: long sleeper) in a beetle. We provided different strengths of vibration stimuli to the long sleepers in Tribolium castaneum. Although immobilized beetles were never awakened by the stimuli from 0.01 to 0.12 mm in amplitude, almost of the beetles were aroused from immobilized status by the stimulus at 0.21 mm. There was a difference in sensitivity of individuals when the stimuli of 0.14 mm and 0.18 mm were provided. F2 individuals were also bred by crossing experiments of the strains selected for shorter and longer duration of TI. The arousal sensitivity to vibration was well separated in the F2 individuals. A positive relationship was observed between the duration of TI and the vibration amplitude, suggesting that immobilized beetles are difficult to arouse from a deep sleep, while light sleepers are easily aroused by even small vibrations. The results indicate a genetic basis for sensitivity to arousal from TI. No potential conflict of interest relevant to this article was reported.