Rather than study butterflies in the environment, the researchers performed meticulous lab experiments on specimens collected in Okinawa, far from any radioactive contamination. The scientists collected plant material from around Fukushima and fed it to pale grass blue butterfly caterpillars.
When the caterpillars turned into butterflies, they suffered from mutations and were more likely to die early than ones that had not eaten radioactive plants. This finding applied even to those butterflies had only eaten a small amount of artificial caesium as caterpillars. "We conclude that the risk of ingesting a polluted diet is realistic, at least for this butterfly, and likely for certain other organisms living in the polluted area," the team concludes.
