USA Today – Science
These tiny, plastic-munching caterpillars can clean up our world – but there’s a catch
A species of caterpillar may provide answers on how to best eradicate plastic waste, a 300 million ton per year problem.
The waxworm, researchers discovered in 2017, is seemingly able to eat through common types of plastic – including polyethylene, a nonbiodegradable type of plastic that is the most commonly used worldwide.
“They are voracious feeders during these larval stages,” Bryan Cassone, an associate professor of biology at Brandon University, told USA TODAY.
Now researchers have offered an explanation: A study published Tuesday in the open peer-reviewed journal Proceedings of the Royal Society B finds that the microorganisms in the wax worm’s gut help them consume and metabolize plastics.
Researchers at Brandon University in Manitoba, Canada, found that waxworms are able to “ingest and metabolize polyethylene at unprecedented rates” thanks to the microorganisms in their intestines.
“The caterpillar’s gut microbiota seem to play a key role in the polyethylene biodegradation process,” the researchers wrote.
Researchers found a greater amount of “microbial abundance” in the caterpillars’ guts when they were ingesting plastic than when they ate a traditional diet of honeycomb.
In waxworms, polyethylene metabolizes into a glycol, which is biodegradable.
Waxworms are not an end-all solution to plastic waste, however. Wax larvae are pests for bees, naturally feeding off honeycomb and running the risk of reducing their populations – and those of plants and crops.
Further, it remains unclear how the plastic breakdown process works in the waxworm, and how its health is affected by its consumption.
The hope, Cassone said, is that if researchers can harness what in the gut bacteria helps caterpillars so easily break down plastic, it can be used to design better ways to eliminate plastic from the environment.
“We envision harnessing the waxworm and its microbiome to develop approaches that do not require whole organisms – rather the products or by-products produced from their interactions that make their ability to breakdown plastic so efficient,” Cassone said.