Atsuki Hiyama et al., "The biological impacts of the Fukushima nuclear accident on the pale grass blue butterfly," Scientific Reports 2, no. 570 (2012): https://doi.org/10.1038/srep00570.
Atsuki Hiyama et al., "The Fukushima nuclear accident and the pale grass blue butterfly: evaluating biological effects of long-term low-dose exposures," BMC Evolutionary Biology 13, no. 168 (2013): https://doi.org/10.1186/1471-2148-13-168.
Dennis Normile, "Fukushima radiation still poisoning insects," Science, September 22, 2014, https://www.sciencemag.org/news/2014/09/fukushima-radiation-still-poisoning-insects.
Becky Oskin, "Mutant Butterflies Linked to Japan's Nuclear Disaster," Live Science, August 14, 2012, https://www.livescience.com/22353-mutant-butterflies-japan-fukushima-disaster.html.
More recent articles and research papers are available at the Otaki Laboratory website.