by Karen Telleen-Lawton, Noozhawk Columnist (read the original in Noozhawk by clicking here)
I am a fan of serendipity. Evolution is governed by serendipity: chance developments that turn out to beneficial to an organism.
In recent science news, it appears evolution has supplied a moth whose larvae have the characteristic of being able to digest plastic. Whether this is beneficial to them or to us remains to be seen.
The discovery of the larvae was a serendipitous event itself. A Spanish biologist, Federica Bertocchini, of Cantabria University, was tending to her bees; her hobby is beekeeping. She noticed that caterpillars had chewed holes through the beeswax and were slurping up the honey.
Curious to identify the species, she gathered some in a plastic shopping bag and brought them back to her house.
When she later went to examine them, Bertocchini found the bag riddled with holes. Caterpillars were scattered about her house.
Most of us would have concluded this unexpected line of inquiry with “ewww,” and disposed of the errant creatures. But being a scientist, Bertocchini was more intrigued, and settled down to figure out who they were.
She found them to be the larvae of the greater wax moth, a well-known predator on bees.
Curious about how the larvae could biodegrade plastic, she teamed up with two biochemists from Cambridge University. They knew that beeswax and many plastics are held together by structures called methylene bridges which most organisms can’t break.
The researchers used a plastic called polyethylene, one of the biggest constituents of garbage dumps, for their test material. Japanese researchers had tested a different plastic-eating species, Nocardia asteroids, on polyethylene.
The wax moth larvae took 40 minutes to chew through the material it had taken N. asteroids half a year to devour. It suddenly looked like plastic bag restrictions could be a thing of the past.
Naturally, this research has unearthed all sorts of questions. One concerns the scale of the problem and resulting required scale of the solution. According to the Guardian, this solution would require billions of caterpillars eating constantly year round to make a dent in plastics.
If I were a bee, or anyone who requires the services of one (which is all of us), I would be quaking in my bees’ knees with that figure.
Recall that bees have been suffering for decades from sudden colony collapse. The added pestilence of a known bee hive predator in the billions might spell their doom.
Bertocchini, for one, is under no illusion that caterpillars themselves will prove to be the solution to plastics in trash, but perhaps they’re a first step.
“We need to dissect the molecular devices responsible for this effect,” she said. “Once we know that, we might be able to produce the hypothetical molecule in large scale and use it as a tool to biodegrade plastic.”
Bertocchini plans to continue the research along with specialized colleagues. But there are no plans to breed the larvae on a mass scale and let them loose to eat the planet’s plastic.
“The idea of actually using the caterpillars never crossed our mind,” she told a Danish interviewer in 2017. “They are a plague for the environment, you cannot throw millions of worms in the environment, the equilibrium in nature must be respected.”
Karen Telleen-Lawton, Noozhawk Columnist
Karen Telleen-Lawton is an eco-writer, sharing information and insights about economics and ecology, finances and the environment. Having recently retired from financial planning and advising, she spends more time exploring the outdoors — and reading and writing about it. The opinions expressed are her own.