A few years ago, a study came out of China on how insect larvae could eat expanded polystyrene, raising hopes about a solution to plastics trash. Then came a study that a certain kind of moth larvae could eat polyethylene.
But don't start celebrating just yet. Fraunhofer Institute in Darmstadt, Germany, has taken a closer look and is strongly urging caution.
"The results to date have been startling: According to the project team, the caterpillars eat holes in PE foil, taking in small amounts and losing considerable body mass in the process," writes Karen Laird, editor of our sister publication Sustainable Plastics. "However, having nibbled through the material, the larvae then stop eating."
Using high-resolution microscopes and computer software modeling, Fraunhofer researchers were unable to determine if the caterpillars even digest the PE. They may just be excreting it as tiny bits of microplastic.
For now, the institute is planning further studies, and encourging consumers to rely on standard recycling systems, rather than the insects in their gardens.