Very Hungry Caterpillar Degrade Plastic at Record Speed

By Rasbak – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17658614

Researchers have found a type of caterpillar can breakdown one of the world’s most common plastics much faster than previously seen. It could be a step towards dealing with water pollution.

The creature in question is a waxworm, the caterpillar larvae of a wax moth and an enemy of beekeepers as it’s a parasite in bee hives. Newsweek notes that chicken embryos researcher Federica Betocchini happens to be a beekeeper and was recently cleaning a hive and removed some waxworms, putting them in a plastic bag. Later she discovered they had eaten their way to freedom.

She tipped off plastic biodegradation experts Paolo Bombelli and Christopher Howe at Cambridge University. They carried out a study and found that the waxworms are able to digest polyethylene, which makes up around 40 percent of the plastics worldwide and is most commonly used for plastic packaging, bags and bottles. It’s particularly resistant to degradation because of its long carbon chains.

While some bacteria and fungi are known to be able to break down polyethylene, this can take between three and seven months to get started and then proceed at a very slow rate. Bombelli and Howe found that a waxworm can make its first hole in around forty minutes and then ramp up to around three holes every hour.

The study suggested the waxworms digest the polyethelene and produce a byproduct of ethylene glycol, which is commonly used for producing polyesters and antifreeze.

While dumping millions of waxworms into the oceans to eat up the discarded plastic isn’t exactly a practical possibility, the researchers believe that learning more about how they are able to break down the plastic could help future anti-pollution measures.

The most likely explanation is that the waxworms house microbes in their stomachs that carry out the degradation, making the waxworms prepared to eat the plastic in a way other creatures wouldn’t. It’s also possible there’s an evolutionary coincidence at work because the plastic has some similarities to waxy products found in beehives.