Mealworms are one of the most versatile organisms on the planet. Not only do they make a wonderful food source for many pets such as lizards, frogs, fish, and even chickens; but they can also be eaten by humans. Furthermore, it has recently been discovered that they have the ability to digest styrofoam without accumulating toxins in their tissues.

On a recent trip to Tractor Supply to pick up some chicken feed, I noticed big bags of dried mealworms stacked on a shelf right next to the feed. I considered picking some up as an extra little treat for our flock. That is, until I saw the price: 11 pounds for $69.99 USD! That’s $6.36 a pound!!

Now, I’ve been considering growing some mealworms on a small scale to use for fishing and little extra handouts for the chickens. But, after seeing how expensive they are, I am more than considering it. It’s time to do some research and make a plan.

Care to learn along with me?

What Are Mealworms?

Chances are that unless you have a reptile as a pet or are REALLY into eating bugs, you are only vaguely familiar with mealworms. You may even be under the impression that they are actual worms! So, before I go on and on about mealworms and how I plan on growing them, I should probably begin by explaining what they are.

For the average person, the most common place where we will encounter mealworms are in the fish bait section at Walmart, the reptile area of the pet store, or for sale as chicken feed or treats. If you have seen mealworms at any of these places, they were most likely the larval form of Tenebrio molitor, a type of darkling beetle commonly called the yellow mealworm beetle. The descriptor ‘yellow’ in the name refers to the color of the larvae, which may start out white but quickly fade to a creamy yellow color. There is one other species of beetle in the Tenebrio family, T. obscurus, the dark mealworm beetle. The adult form of two species may be difficult to tell apart from one another; but interestingly, one of the distinguishing characteristics is that dark mealworm beetles are often a lighter shade of brown than yellow mealworm beetles. The descriptor ‘dark’ in the common name for T. obscurus is in reference to the color of the larvae of the species. Sold as mini mealworms due to the fact that they grow to about half the size of their yellow cousins, these “worms” start out white but change to a dark brown.

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Mealworm Diet

Mealworms and mealworm beetles derive their name from the fact that they eat grain and grain meal. They prefer old, moist grain or meal that is beginning to decay, but are willing to dine on fresh cereal products as well. In fact, people who raise mealworms generally feed them fresh whole oats or bran. Alternatively, you might also be able to feed them Styrofoam. More on that later in the article.

Mealworms IN A Diet

The most common use for mealworms is probably as reptile food. Live mealworms make excellent food for pet lizards. They make an easy, safe target for pets who refuse to eat prey that is already dead. Chickens also love them, and they are even on the menu for humans. And, after looking at their nutrition information, it’s no wonder! Mealworms are super easy to grow; they provide over 1,500 dietary calories per kilogram; and they are a decent source of fats. They are also high in vitamins, minerals, and amino acids, making them a good all-around source of nutrition. They are said to taste a bit bland with a slight nutty flavor, making them good additives to dishes. I have eaten mealworms on one occasion in a fruit chutney on a cracker. It was a long time ago, and I was mostly just trying them out for the experience, but I recall that it was not half bad! More recently, my son and I each tried one as an “Eat A Bug” challenge at the State Parks Department booth of a local festival. Again, once you get the thought of “I’m eating a bug larva” out of your head, they are not bad. Our Little Homestead Helper even tried one! In fact, if given the opportunity to eat one of Ikea’s mealworm burgers, I would jump at it! Mayo, lettuce, and tomato, please!!

Environmental Superheroes?

Here is something that I just learned about mealworms while prepping for this article: they can safely eat polystyrene!

Styrofoam is EVERYWHERE, these days. It is used to make all kinds of stuff: disposable cups, plates, and lunch trays; packing peanuts and other space filling materials; disposable coolers; insulating sheets; etc. The problem is, the stuff takes forever to break down naturally. Estimates on how long it persists in the environment range from 500 years to FOREVER!

However, recent studies show that mealworms can EAT polystyrene. Now, this is kind of a big deal. Polystyrene contains a litany of toxins. One of these toxins is a flame retardant known as HBCD. In a 2015 study, scientists found that mealworms were able to digest polystyrene, converting about 50% of it into carbon dioxide and the rest into solid waste. A follow up study attempted to find out how eating plastic affected the mealworms and whether it resulted in the mealworms building up toxins in their bodies. Not only did they find that the polystyrene-fed larvae were just as healthy as the grain-fed control group, it also found that the larvae passed all of the toxins out of their system within 48 hours. So, in theory, mealworms that have a diet of polystyrene could safely be fed to lizards, chickens, or even people.

Now, this is not a magic bullet solution for Styrofoam pollution. The toxins that passed through the mealworms did end up in their frass, so it would have to be disposed of somehow instead of being composted. And, while this particular study traced HBCD and a few other chemicals, further study would have to be done to ensure that other toxins were not retained within the larvae.

In Conclusion

While mealworm beetles are considered to be agricultural pests, their larvae have the potential of becoming a sustainable dietary staple for everything from pets to agricultural animals to humans. Furthermore, there is promising data that shows they may be able to help rid the world of some of its polystyrene pollution, as long as we can find responsible ways to deal with the toxic waste that they produce after eating it.

Stay tuned. Next up, we’ll take a look at the life cycle of T. molitor. This is the species that I am interested in growing, so I would like to learn a little bit more about their reproduction, growth, and development.