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Mealworms: The Other-Other-Other White Meat?

The views expressed are those of the author and are not necessarily those of Scientific American.

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Image of mealworms and crickets courtesy of genmaichaita/Flickr

Looking for the perfect holiday entrée? Something nutritious yet easy on the Earth? Something with a subtle, yet distinctive, je-ne-sais-quoi flavor? Have you considered the humble mealworm? What about the super superworm?

Before you click away in disgust, remember that the creeping, shelled, 10-legged crustacean we now so lovingly dip in butter (ahem, the lobster) was once considered so repulsive as to be inhumane to feed to prisoners. And in many parts of the world, insects are already a popular—and important—menu item.

A new study, published online December 19 in PLoS ONE, makes the case that the mealworm (Tenebrio molitor) and the superworm (Zophobas morio)—consumed as larval forms before they become beetles—are palatable (ecologically speaking) alternatives to traditional livestock products.

Rearing cows, pigs and chickens is an intensive ecological endeavor. Currently, more than two thirds of all agricultural land is used for animal production (whether housing the animals themselves or growing feed crops for them). This whole process—from fertilizing grain to raising (farting) cows to shipping milk—produces some 15 percent of all human-generated greenhouse gasses. Many climate-minded researchers have advocated switching to a more plant-based diet as a way to reduce these harmful emissions. But bugs might be an opportunity to keep animal protein on the menu.

Mealworms might be more familiar to pet owners as reptile, fish or bird food. But these insects are already available freeze-dried, canned or live for human consumption and can be baked into breads and cookies, deep fried with potatoes for more nutritious French fries or simply roasted with some salt for a protein-rich snack.

For the new study, researchers examined the process of raising these two insects—the “cradle-to-farm-gate approach,” as they noted. Dennis Oonincx, of the Department of Plant Sciences, and Imke de Boer, of the Animal Department of Animal Sciences (both at Wageningen University) studied a Dutch mealworm producer called van de Ven Insectenkwekerij in the town of Deurne. The worms were fed a diet of carrots and mixed grains. The insects also required recycled cardboard egg trays, a climate-controlled rearing station (which requires natural gas and electricity), cages, as well as water.

Nevertheless, they appeared to be a more sustainable source of protein than beef, pork, chicken or milk. To produce one kilogram of protein, including feed growing, the mealworms required just one tenth the amount of land required to produce one kilogram of beef—and much less than chicken, pork and milk, too. Producing one kilogram of mealworms generated about 2.7 kilograms of carbon dioxide equivalent in greenhouse gas (mealworms do not produce earth-warming methane, like gassy ruminants do, although the worms do produce their own tiny manure), which is far less than the standard livestock lineup. The lion’s share (42 percent) of the mealworms’ greenhouse gas contribution came from producing and transporting grain feed (26 percent of the CO2 came from the heating gas; 17 percent came from the electricity; and 14 percent came from the production and transportation of carrots).

The study authors suspect that with additional research, the bugs could become an even more Earth-friendly option. “Over the last two decades productivity of chickens and pigs has increased annually by 2.3 percent, due to the application of science and new technologies,” they wrote in their paper. “Further improvement of the mealworm production system by, for instance, automation, feed optimization or genetic strain selection is expected to increase productivity and decrease environmental impact.”

The mealworms are already quite efficient at turning mealworm food into mealworm-based food for humans. They can convert about 2.2 kilograms of food into a kilogram of total bug weight (which is similar to chickens and a much better rate than pigs and cows). They are also proficient reproducers. The female mealworm T. molitor matures in about 10 weeks and will lay some 160 eggs in her short three-month life; and the impressive female superworm Z. morio reaches maturity in three and a half months and can lay some 1,500 eggs in her year of life.

Perhaps most important, the authors concluded, was the mealworm’s small land demand. Forest clearing for agricultural use is a major global contributor of greenhouse gas emissions. “Since the population of our planet keeps growing, and the amount of land on this earth is limited, a more efficient, and more sustainable system of food production is needed,” Oonincx said in a prepared statement. “Now, for the first time, it has been shown that mealworms, and possibly other edible insects, can aid in achieving such a system.”

So perhaps insects will someday graduate from novelty candy and double-dare tequila shots to a meal’s main attraction. Even if they aren’t yet replacing many holiday hams.

Katherine Harmon Courage About the Author: Katherine Harmon Courage is a freelance writer and contributing editor for Scientific American. Her book Octopus! The Most Mysterious Creature In the Sea is out now from Penguin/Current. Follow on Twitter @KHCourage.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. Sue W 9:18 pm 12/19/2012

    But how do they taste?

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  2. 2. RobbyM 9:48 pm 12/19/2012

    They have a very subtle taste. I found they tasted a bit like a cross between unflavoured popcorn and peanuts, but mostly like popcorn.

    I used to raise them for food for a couple years, much to my landlady’s displeasure. It’s not very hard, though I was unable to grow very much.

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  3. 3. Xopher425 10:07 pm 12/19/2012

    Very crunchy, not a great deal of flavor, kind of savory. I imagine that one would have to eat several to really get a good idea of taste. I manage a pet store, we sell tons of these (I haven’t done the taste testing, the other manager has. She prefers wax worms.)

    This is very interesting, but one thing I wonder about: cost of processing these insects into food. I don’t doubt that they are “cheaper” environmentally to raise, but there is a lot of chitinous shell there to process out (most people don’t like that much crunch). Separating that from the edible “meat” would be labor intensive (machines would not do a very efficient job). For mass market scale, it could then be processed and formed into shapes, maybe even flavored – natural, chicken, BBQ, ranch! – into regular pieces of meat. And while it would be expensive, it would still probably be cheaper than the other sources of protein.

    They could be fried up and used as toppings on salads . . . . a little butter and garlic, sounds tasty (but then anything is tasty with enough butter and garlic).

    Like the comment about lobsters. They really are the roaches of the sea, and yet are a delicacy. It all depends on how you look at it.

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  4. 4. oldvic 5:22 am 12/20/2012

    Feeding carrots and mixed grains to worms is a wasted step as far as I’m concerned. I like carrots and mixed grains.

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  5. 5. Clark Bennett 3:04 pm 12/20/2012

    If the product doesn’t look like meal worms and isn’t called meal worm and you don’t shove in their face that it’s made from meal worms, then there probably won’t be that big of an adoption problem. You generally don’t go to the grocer and ask for a pound of ground pig or cow.

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  6. 6. eric_j 5:32 pm 12/20/2012

    Why bother with almost tasteless worms when you can get plenty of protein with less effort from the other-other white meat: Fungus. All animal (including insect) methods of converting raw nutrients into edible cells are inefficient. Fungus can convert such nutrients to protein-rich edible cells with roughly the same number of steps as a plant…

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  7. 7. Acoyauh2 7:52 pm 12/27/2012

    @Xopher425: Insects are processed complete; the shell and legs (where available) can be eaten too, or just grind the whole buggers to produce a kind of flour.

    There are about 3000 edible instect species in Mexico alone; I understand parts of Asia are even richer and no doubt Africa would gladly enrich the menu if we looked there, too.

    Some species are cultivated for a ‘mid-way’ solution, as poultry or pig food rather than human consumption. These species are useful for recycling waste materials like cellulose, rather than consuming human-usable resources and also produce high quality protein.
    If America (and the West in general) ever overcome their revulsion to insects, there is a whole, delicious world out there waiting – and plenty of Earth-friendly solutions to be pursued too.

    Personally, I love avocado worms, ant larvae (escamoles), grasshoppers (chapulines), and jumiles (which look like bedbugs). The already famous maguey worm found in the mezcal bottles is served in full plates. I have disliked none so far in my trips to Southern Mexico, but did refuse to bite into a live, huge, blackish, viscous and ugly looking bug offered to me in Oaxaca… I guess not all of them are for everyone.

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  8. 8. Acoyauh2 8:00 pm 12/27/2012

    @1. Sue W: It depends how you cook them. I recommend green tomato sauce & herbs. Add vegetables to taste for a full meal.
    As a snack, try roasting them with a bit of butter, salt and a touch of garlic or onion. Sit at the TV and enjoy =)

    No, I’m not joking. It’s like any other meat, try a bit of unseasoned, raw, ground pork or beef and see if you like it.

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