Table of Contents

Image courtesy of CNN.

Mealworms, Plastic, and the Environment

It turns out that mealworms are more than just the occasional snack for our scaled friends, they might also be able to help with a huge environmental problem. Recently it’s been discovered that mealworms can actually eat plastic, specifically polystyrene, which means that we may need to re-think the way that we look at these already-interesting beetle larvae.

The Problem

If you’ve ever lived in a city, you’ve seen part of this problem. Styrofoam cups and plates abound just about everywhere and they cause quite a mess. Even worse, few facilities actually recycle polystyrene, leading to a large amount of build-up in landfills and other waste disposal facilities.

Polystyrene is a huge component of plastic waste, and makes up a huge amount of the plastic waste that litters our waters, landfills, and even the areas we live in. Chunks of the stuff are notorious for choking animals to death.

There’s some evidence that when the sun degrades polystyrene in the presence of nitrogen oxides, it releases tropospheric ozone. While our ozone layer is a concern, it’s also a serious pollutant at ground levels.

A Possible Solution

A study showed that one hundred mealworms consumed 34-39mg of polystyrene a day. A foam cup weighs roughly 1.5g and it would take one hundred meal worms roughly 37 days to eat one. The amount they eat isn’t the breakthrough though, but we’ll get to the breakthrough in a moment. Let’s talk about the worms that subsisted on this diet, which surely can’t be healthy for them.

The fact of the matter is, the larva fed on Styrofoam were just as healthy as any other mealworms. Their droppings were also deemed to be non-toxic, which means that however mealworms digest the polystyrene actually degrades the material to a level that it’s a usable material that can be added back into the environment. Pretty impressive for something we normally just throw to our animals without a second thought.

The only real waste product produced by the mealworms are their castings, which can be utilized in soil, and carbon dioxide. While the latter might sound a bit scary with all the concern surrounding the greenhouse effect, the mealworms actually produce it regardless of what they eat just like most organisms.

As far as solutions go, this might be a massive revelation. While the news media has portrayed their ability to eat Styrofoam as a solution in and of itself, the amount they eat per day doesn’t make this very likely. The adult form of the larvae doesn’t seem to eat Styrofoam, and the idea of massive facilities filled with millions of mealworms probably isn’t the best solution to the problem.

Researchers are pretty sure that the ability of the mealworms to digest plastic doesn’t come from an enzyme they produce, but instead from a certain variety of microfauna which is present in their digestive tract. There have been some experiments with culturing this bacteria in order to break down the material outside of their guts which have had a pretty impressive level of success.

On a smaller scale, if you raise a lot of mealworms you might be able to dispose of your own household waste in this manner. We can’t really recommend feeding these worms to your pets, however, since undigested polystyrene remaining in their gut is probably dangerous to your animals. With some research, though, it may be a viable form of composting, provided your home doesn’t use excessive amounts of Styrofoam.

Conclusion

Mealworms apparently aren’t just a great treat for your reptiles, their amazing ability to digest a plastic which was thought to be completely non-biodegradable might have huge implications for the future. The more we study insects, the more we find that different arthropods might become our greatest allies as we move into a future which poses new challenges.