Wax moth could be used to get rid of plastic, researchers find

When placed in plastic bag the wax moth larvae quickly leave it riddled with holes

Scientists at the Marine and Freshwater Research Centre at the Galway-Mayo Institute of Technology are trying to find out how plastic pollution is impacting the environment and human health. Video: Kathleen Harris

 

Moth larvae could potentially revolutionise how the world disposes of plastic waste after an accidental discovery by a scientist and amateur beekeeper.

Spanish scientist Dr Federica Bertocchini has found that wax moth larvae, commonly used as fish bait, are able to eat through plastic.

The wax moth larvae are known for eating bee honey and infesting beehives. Dr Bertocchini, who keeps bees in her spare time, discovered the moth grubs in one of her hives.

She removed the pests and placed them in a plastic shopping bag, but when she returned some time later found the moth larvae had chewed their way through the plastic.

The chance incident led Dr Bertocchini, a researcher in the Spanish Institute of Biomedicine and Biotechnology of Cantabria in Santander to investigate the phenomenon, alongside scientists from Cambridge University, England.

In a follow-up test conducted in Cambridge, 100 wax worms were let loose on a plastic bag from a British supermarket.

Holes began to appear after just 40 minutes, and over a period of 12 hours 92 micrograms of plastic was consumed.

Irish plastic waste

Most recent figures show that each year Ireland produces 169,000 tonnes of plastic packaging waste, on average about 37kg per person.

European Union parliament directives have set minimum plastic recycling targets for Ireland to reach in the coming years.

Ireland has signed up to aim to recycle 22 per cent of its plastic packaging waste back into other plastic products.

According to the Environmental Protection Agency (EPA) statistics from January 2017, Ireland is just under halfway to reaching its target for recycling plastic waste.

In comparison the State is 80 per cent of the way towards achieving its EU recycling targets for paper, metals, and glass.

Currently around 38 per cent of discarded plastic waste in Europe ends up in landfill sites.

The scientist behind the encouraging discovery said that “plastic is a global problem. Nowadays waste can be found everywhere, including in rivers and oceans”.

Dr Bertocchini outlined that “the caterpillars are not just eating the plastic without modifying its chemical make-up”.

“We showed that the polymer chains in polyethylene plastic are actually broken by the wax worms.

“The caterpillar produces something that breaks the chemical bond, perhaps in its salivary glands or a symbiotic bacteria in its gut,” Dr Bertocchini said.

“The next steps for us will be to try and identify the molecular processes in this reaction and see if we can isolate the enzyme responsible.”

The State has been attempting to reduce the amount of plastic bags and packaging it produces.

The 15 cent plastic bag levy was introduced back in 2002 in order to encourage Irish people to cut down on the amount of plastic waste they use and throw out.

Figures from the Department of Environment show the government’s intake from the plastic bag levy has consistently dropped since 2010, indicating a fall in the number of plastic bags sold.

In 2010, the government’s plastic bag levy brought in €17.4 million, before falling to €13.8 million by 2012, and again to €12.7 million in 2014.

The most recent figures available show the State brought in €11.7 million from the plastic bag levy in 2015.