Discovery of beetle larvae that can digest polystyrene

SCIENTISTS have discovered a new species of beetle larvae that can digest polystyrene, driving hopes that it could help solve the plastic crisis.

Polystyrene, one of the most common packaging plastics, can take centuries to decompose naturally.

But scientists at Pohang University of Science and Technology in South Korea found one larvae, or mealworm, of the darkling beetle could digest 34mg of Styrofoam boxes over two weeks.

The findings add to earlier studies on the plastic-eating potential of the mealworm, which was first discovered to eat polystyrene by researchers at Stanford University in 2015.

The latest, a species most commonly found in north-east Asia, is now the fourth beetle larvae known to do the job. The mealworms normally feed on rotting wood, which has a similar chemical structure to polystyrene.

There are drawbacks. Almost half of the plastic is expelled from the mealworms as carbon dioxide and it remains a slow process that scientists have so far been unable to find a way to speed up. It is also unlikely to occur in the natural world as a mealworm will only eat the polystyrene as a last resort.

The South Korean researchers hope their study will help isolate the bacteria that creates the process, which could pave the way to developing a separate product that would break down polystyrene at a much faster rate.

“There is the chance that we could completely biodegrade polystyrene, which has been difficult to completely decompose, to ultimately contribute to solving the plastic waste problem that we face,” said Prof Hyung Joon Cha, who led the study.