Used plastic bags may be one man’s trash, but to wax worm caterpillars, or Galleria mellonella, they are a veritable banquet. These polymer-chomping caterpillars are the larvae of honeycomb moths. In nature, wax worms eat the wax in honeycombs made by bees and wasps, making them an enemy of apiarists everywhere.
Researchers at Cambridge University published a study on Monday, April 24, 2017, about the potential benefits of the voracious wax worms. BBC News reported that the plastic bag-devouring wax worms could be very important allies of humans in combating plastic pollution. Developmental biologist Federica Bertocchini, a researcher at the Institute of Biomedicine and Biotechnology at the Universidad de Cantabria in Spain, according to Forbes, described the wax in honeycombs as being “a polymer, a sort of ‘natural plastic.'”
Continuing, Dr. Bertocchini, a beekeeper, said that wax “has a chemical structure not dissimilar to polyethylene.” She first became aware of the plastic-eating abilities of wax worms when she cleaned a horde of wax worms from beehives, empty of bees, she had in her house. Dr. Bertocchini put them into a plastic bag, and she said before very long, the wax worms had escaped and were all over her house. She saw that there were little holes in the plastic bag, and after she collected them back again, she observed them at work, making a meal out of their see-through jail cell.
Wax worms are able to break down plastic polyethylene’s chemical bonds similar to the way they can digest the beeswax in beehives. It can take centuries for plastic bags, food packaging and other products made with polyethylene to completely decompose, but in less than an hour, wax worm caterpillars are able to get a good start on the process, by riddling plastic bags full of holes, like Swiss cheese.
According to Dr. Paolo Bombelli, a biochemist at the University of Cambridge and one of the researchers who took part in the study, the researchers would like to minimize “the problem of plastic waste” through what he called a “technical solution.”
The discovery that wax worms can be used to help solve the world’s plastic pollution problem has been patented by Dr. Bombelli and Dr. Federica Bertocchini. Microbes within the wax worm caterpillars, they believe, as well as the insect, itself, could be responsible for the their ability to break down and devour plastic.
According to Forbes, the researchers at Cambridge and in Spain determined that the wax worms were not just chewing up the plastic and spitting it out, but were actually eating it. An examination of the guts of the wax worms detected the tell-tale presence of ethylene glycol, proof that the insects were “digesting polyethylene.”
Wax worms eat plastic bags and other plastic waste matter fairly quickly, the Dr. Bombelli and Dr. Federica Bertocchini learned. Live Science reported that Bertocchini said that she and the other researchers involved carried out a series of experiments to discover how fast they were at “biodegrading polyethylene.” She stated that a hundred of the insects were “capable of biodegrading 92 milligrams [0.003 ounces] of polyethylene in 12 hours.” She said that was really “very fast.”
The two researchers are working to identify the chemical process involved within the wax worm caterpillars, so they can attempt to accomplish the same thing that the insects do, break down waste plastic in the environment, on a wide-scale basis. Dr. Bertocchini said that finding out how to manage plastic waste should not provide humans with an excuse, or justification, “to dump polyethylene deliberately in our environment.”
Anybody who has ever owned a pet lizard or bird likely has seen wax worms, because they are sold at pet stores as pet food for birds and reptiles. Honeycomb moths are “native to Europe and Eurasia.”
Wax worms are the bane of many beekeepers, or apiarists, because they eat the waxy honeycombs bees and wasps make. However, perhaps because wax has similar characteristics of polymers, wax worms consider plastic bags and other items made of polyethylene a veritable banquet, making them potentially extremely important in cutting down plastic pollution around the world. While further research is needed, it could turn out that the lowly wax worm might provide the key to finding out a fairly rapid and safe method of degrading products made out of plastic.
By John Samuels
Photo Courtesy Federica Bertocchini, Paolo Bombelli and Chris Howe