Kitchen pests chomp through plastic waste

Finding pantry moths in the cupboard usually inspires a kitchen cleanout. Now scientists have discovered the pesky creature may be able to help with recycling too.

The larvae from the Plodia interpunctella, otherwise known as pantry moths or Indianmeal moths, have gut bacteria that can degrade polyethylene, the most common plastic. Reported in the American Chemical Society’s journal Environmental Science & Technology, the finding could lead to new ways to help get rid of the otherwise persistent waste, the scientists say.

The global plastics industry churns out about 140 million tons of polyethylene every year, with much of it going into the bags, bottles and boxes that are used - and discarded - every day.

Recent studies have tried using bacteria on plastic to degrade it, but these required first exposing the plastic to light or heat. The team led by Jun Yang, an environmental engineer at China’s Beihang University, wanted to find bacteria that could degrade polyethylene in one step.

An infestation in his own kitchen caused Yang to wonder if the larvae were able to digest the plastic bag that his millet was packaged in, as well as its contents. His team found that at least two strains of the larvae’s gut microbes could degrade polyethylene without a pretreatment step. They say the results point towards a new, more direct way to biodegrade plastic.