The pale grass blue butterfly in ex-evacuation zones 5.5 years after the Fukushima nuclear accident: Contributions of initial high-dose exposure to transgenerational effects

•Abnormality rate was correlated with the initial 131I and 137Cs deposition levels.•Capture rate was negatively correlated with the initial 137Cs deposition level.•The butterflies in the ex-evacuation zones in 2016 were still likely affected.•The initial high-dose exposure to radionuclides likely contributed to the effects.