You have probably seen those videos showing mealworms eating apples, fish, shrimp, bananas etc. It seems like these larvae beetles can handle whatever you throw at them. But can mealworms really eat everything?
Mealworms are best known for eating decomposing matter, but they can also consume plastic and other materials. However, they have a difficult time digesting salty and spicy food.
What Mealworms Can Eat
Mealworms primarily feed on decaying organic matter in the wild. But they can also consume other food sources. These versatile insects have a reputation for being exceptional recyclers and it is justified. While not worms (they are actually the larvae form of beetles), they are excellent at recycling waste.
The ability of mealworms to eat just about anything says a lot about their adaptability. But mealworms grown in farms are fed a balanced diet to ensure optimum health. Since these mealworms are commercially sold, they have to be fed healthier foods.
The ideal diet for mealworms consists of organic matter, grains, fruits, and vegetables. This ensures they receive nutrients needed for growth and reproduction.
While mealworms can consume almost anything, there are certain substances or materials that should be avoided. Toxic or poisonous substances, chemicals, pesticides, and heavily salted foods should never be fed to mealworms. These can have detrimental effects on their reproduction and health.
What Not to Feed Mealworms
Mealworms are commonly used as food for reptiles, birds, and fish due to their rich protein content. If you use mealworms as animal feed, pay close attention to what you feed them. Because what goes into the mealworms ends up in the animals you feed.
Citrus fruits: The acidity in these fruits can be harmful to their digestive system and cause health issues. If you want to try it anyway, do so in small amounts. Observe if the mealworms will eat them. Even if they eat citrus, limit the amount.
Sugary foods: Foods high in sugar like candies, chocolates and pastries should be avoided. Sugar can disrupt their digestive process. Sugar can also lead to weight gain and other problems.
Dairy products: Mealworms are capable of digesting dairy products like milk, cheese, or yogurt. Feeding them these can lead to digestive problems and lead to nutritional deficiencies. In severe cases it can be fatal.
Spicy foods: Spicy foods and seasonings can cause irritation, ulcers, or even severe damage to their digestive tracts. Their digestive tract cannot handle the heat either.
Processed or salty foods: Foods that are high in sodium or heavily processed aren’t good for mealworms. They have limited capacity to process these compounds. Too much could lead to dehydration and nutritional imbalance.
Other Things to Avoid
Foods treated with pesticides: harmful and toxic chemicals can be fatal to mealworms. Even if they somehow survive, these substances will accumulate in their bodies. If you feed mealworms to animals, these chemicals could cause serious health problems.
Moldy or rotten food: Mealworms are susceptible to fungal infections and other diseases caused by moldy or rotten foods. Fresh, uncontaminated food is ideal for their survival. It’s true mealworms may eat rotten food in the wild, but only if there is no choice. Those raised in controlled environments should not be fed rotten food.
Related. How to Clean a Mealworm Farm
Can Mealworms Eat Plastic?
One of the most interesting aspects of mealworms’ diet is their appetite for plastic. Recent studies have suggested that mealworms can break down and consume certain types of plastic, including polystyrene foam.
Polystyrene foam is commonly used in packaging and is an environmental hazard. The ability of mealworms to consume this plastic suggests that they can be used for waste management.
What Science Says
Researchers have conducted experiments to determine the mealworm’s capacity to break down plastics. From their studies, scientists learned that mealworms can digest polystyrene, a type of plastic used in food packaging and disposable products.
Mealworms are able to break down the polymer chains found in polystyrene through a process known as depolymerization. There is still a lot of research ongoing, but there’s no question mealworms are being looked into as a solution for our plastic pollution problem.
How Mealworms Digest Plastic
One study conducted by scientists at Stanford University in 2015 revealed that mealworms could break down polystyrene foam and reduce the volume by 50%. Further research showed that the mealworm’s gut microbiome plays a crucial role in this process.
It turns out the bacteria in a mealworm’s gut aids in the depolymerization of plastic, allowing them to metabolize it.
I have to emphasize that mealworms cannot digest all types of plastics. They can only digest and process polystyrene. Mealworms cannot easily digest other plastics like polyethylene and polypropylene. Even when they do, it does not metabolize as well as polystyrene. Even so, just reducing our polystyrene waste output would be huge.
Waste Management Potential
While mealworms show promise in reducing plastic pollution, there are still challenges ahead. However, their ability to aid in waste management (even if restricted to specific plastic types) has sparked interest among scientists and policymakers looking for sustainable solutions.
I also believe studying the potential of mealworms for waste management also contributes to the development of biodegradation technologies. In my case it provides insights into the natural mechanisms behind plastic decomposition.
Mealworms alone will not solve our plastic pollution problem. But they offer a glimmer of hope that we can find waste management solutions to this issue.
How Mealworms’ Digestive System Works
If you really want to know how mealworms can eat just about anything, we have to understand how their digestive system works.
It starts with their mouthparts, which are specialized for chewing. Mealworms have strong mandibles that allow them to grind and crush food into smaller pieces. This is how they can chew fruits, vegetables, organic matter and other materials.
The Digestive System
After a mealworm chews and swallows the food, it goes into the esophagus. The esophagus is a muscular tube that leads to the crop.
The crop serves as a temporary storage compartment so mealworms can eat large amounts of food in one sitting. This ability is important because it allows mealworms to survive for long periods without eating.
From the crop, the food enters the proventriculus. This glandular organ acts as a valve that regulates the flow of food into the midgut. It secretes enzymes and acids to break down the food.
The midgut or intestine is where digestion and absorption take place. It is a long, coiled tube where enzymatic reactions take place.
Various enzymes like proteases, lipases, and carbohydrases are secreted by the midgut to break down proteins, fats, and carbohydrates. These enzymes assist in the breakdown of complex food molecules into simpler substances that can be absorbed by the mealworm’s body.
Food into Nutrients
As food continues through the midgut, nutrients such as amino acids, sugars and fatty acids are absorbed into the bloodstream. Midgut cells have microvilli, which aids in digestion and nutrient absorption.
Undigested food turns into waste and is sent to the hindgut or rectum. Mealworms reabsorb a significant amount of water from fecal matter, which enables them to thrive in dry environments. This also lets them last for long periods without water. The remaining waste material or frass is excreted, completing the digestive process.
Conclusion
Mealworms are not just voracious eaters, but their ability to eat all kinds of stuff is remarkable. It is fun to feed them all sorts of things to see if they’ll eat it, but for mealworm farmers, a balanced diet is a must.
And as it turns out, their eating prowess can also help us solve our waste management problems, in particular plastic. There’s a lot of research to be done, but it looks promising for sure.
