Caterpillar joins fight against plastic

PARIS - A moth caterpillar commonly bred to provide fish bait feasts on a notoriously resistant plastic, scientists reported on Monday, raising hopes the creature can help in the fight against pollution.

"This discovery could be an important tool for helping to get rid of the polyethylene plastic waste accumulated in landfill sites and oceans," said Cambridge University professor Paolo Bombelli, co-author of a study published in the journal Current Biology.

Polyethylene represents 40 percent of Europe's demand for plastic products, mostly in the form of packaging and shopping bags.

Taking years to biodegrade, these objects constitute a hazard for the environment when they are not recycled.

In the European Union, 38 percent of plastic is thrown out in landfills.

The promising discovery centers on the wax worm - the name for the caterpillar larva of Galleria mellonella, or greater wax moth.

In its pre-caterpillar form, the species is commercially raised as maggots to provide fish bait and aquarium food.

The find happened by accident at the home of the study's lead author, Federica Bertocchini, a biologist at the Institute of Biomedicine and Biotechnology of Cantabria in Spain.

Bertocchini keeps beehives as a hobby.

"When I went to clean them for reuse in the spring, they were infested with (wax) worms," the researcher said.

"So I put them in a bag. Then, after a while, I saw the bag was full of holes and these caterpillars were crawling all around my place."

The answer may lay in the worm's habitat and eating habits.

Growing in bee colonies, the moth larvae feed on beeswax, a digestive process that scientists believe may be similar to breaking down polyethylene.

"Wax is a polymer, a sort of 'natural plastic', and has a chemical structure not dissimilar to polyethylene," Bertocchini said.

It remains unclear if a single enzyme or a combination of molecules are responsible for degrading plastic. But biologists hope to identify and reproduce the active agent artificially.