In my book, A Heaven for Toasters, the main source of protein is insects and lab-grown meat (I only hint at this, so don’t worry if you missed that). As with all things futuristic, I based this on current trends. One of these is using maggots, specifically the larvae of black soldier flies, as food.
As The Washington Post reports, for years, the larvae of black soldier flies have been harvested and sold as food for exotic pets such as lizards, birds, even hedgehogs. This is part of a burgeoning industry, one with the potential to revolutionize the way we feed the world. That’s because of the black soldier fly larva’s remarkable ability to transform nearly any kind of organic waste — cafeteria refuse, manure, even toxic algae — into high-quality protein, all while leaving a smaller carbon footprint than it found.
In one year, a single acre of black soldier fly larvae can produce more protein than 3,000 acres of cattle or 130 acres of soybeans. Such yields, combined with the need to find cheap, reliable protein for a global population projected to jump 30 percent, to 9.8 billion by 2050, present big opportunity for the black soldier fly. The United Nations, which already warns that animal-rich diets cannot stretch that far long term, is encouraging governments and businesses to turn to insects to fulfill the planet’s protein needs.
People who’ve seen what black soldier fly larvae can do often speak of them in evangelical tones. Jeff Tomberlin, a professor of entomology at Texas A&M University, says:
The bug industry could save lives, stabilize economies, create jobs and protect the environment. There’s no reason why we shouldn’t be doing this at some scale throughout the world.
So why aren’t we?
A Yucky Dead End
The adult flies resemble small black wasps, minus a stinger, and are generally harmless to humans. After they’ve mated, the females deposit clutches of several hundred eggs into small pieces of corrugated cardboard. Employees collect the cardboard and deposit them into glass Mason jars to incubate. Several days later, a brood of maggots — each no bigger than a speck of pepper — hatches.
Entomologists have known of the soldier fly’s promise for decades. Researchers proposed using them to convert manure into protein as early as the 1970s.
But raising them at anything approaching a commercial scale seemed like a dead end: No one knew how to get captive flies to reliably mate and deposit eggs.
Raising Insects in Captivity
That changed in 2002 with the publication of a paper, by Tomberlin and others, which described a system for raising the insects in captivity. The key, the researchers found, was finding the precise mixture of temperature, humidity and, especially, lighting to stimulate the flies to breed.
The larvae at Evo, a company specializing in larva-growing, feast on spent grains from a handful of Texas distilleries and breweries, as much as 15 tons of it each month. Nathan Barkman of Rio Brazos Distillery said Evo eliminates close to half of his company’s weekly output of waste. It’s hot, sopping wet, highly acidic and sticky — “like lava,” he said — making it difficult to dispose. Local sanitation companies won’t take it. Pig farmers sometimes will, but the closest farms are miles outside of town, and nobody wants to be driving molten grain mash that far.
The flies, however, love it. They’re generalists and eat just about anything. Pig manure? Check. Human waste? Check. Food scraps? Check. The only organic materials they haven’t had luck with are bones, hair, and pineapple rinds.
An Ecological Game-changer
Their ability to rapidly devour waste has inspired a number of commercial applications. A pilot program at Louisiana State University deploys a small colony of soldier flies to consume the food its students toss out at one dining hall. The entomologist overseeing the project hopes it will be expanded to eliminate all campus food waste by the end of the year. In China, giant facilities owned by a company called JM Green process at least 50 tons of food waste a day with the help of black soldier flies.
Using larvae to eliminate food waste at this scale could be an ecological game-changer. A 2011 U.N. report detailed how rotting food emits millions of tons of carbon dioxide into the atmosphere, accounting for about 7 percent of the world’s greenhouse gas emissions. But when maggots consume food waste, they take all that carbon with them.
Soldier flies are “where carbon goes to die,” Tomberlin said. “It goes into this system and comes out the other end as all these beneficial ingredients.”
Such as food for animals.
One of the first commercial applications for soldier fly larvae was as live feed for pet reptiles. But that was just the beginning.
An acre of land used to raise soldier fly colonies can produce more than 130,000 pounds of protein per year. Compare that to the per-acre protein yield of cattle (about 40 pounds), soybeans (950 pounds) or chickens (1,800 pounds).
Liz Koutsos is chief executive of Kentucky-based EnviroFlight, which raises soldier fly larvae used in protein meal for commercial fish and poultry operations. As she explains:
Black soldier fly larvae can make thousand-folds more protein than terrestrial animals or other plants.
The yields are so high because soldier fly colonies can be stacked vertically, five to 10 per floor, in a way that isn’t possible with cattle or field crops. The fast-growing larvae also can be harvested dozens of times per year.
A Fishy Future
Black soldier fly meal won approval as fish and poultry feed in 2018. Companies around the world are working to win regulatory approval for using the meal in food for other animals, including swine and even cats and dogs.
The idea is to take the pressure off traditional sources of protein meal, such as fish. About one-quarter of the harvest from marine fisheries is turned into food for farmed animals, including fish, hogs, and poultry. More than 90 percent of those fisheries are either fully exploited or overfished, meaning that as the world’s population grows, there will be more demand for alternative protein sources.
“There’s no question that [soldier fly] meal is much more expensive right now than fishmeal,” Koutsos says. But fishmeal is becoming more expensive, and soldier fly technology is becoming cheaper. The goal, she said, is “to be at or below fishmeal [price] in five years.”
How About Humans?
The U.N. agrees: It forecast in a 2013 report that insect farming would have to play a key role — both as animal feed and to feed people — if the world is going to be fed sustainably in coming decades.
Back at Evo, an employee pops a couple of oven-dried soldier fly larvae into her mouth:
Honestly, they taste like Fritos.
They have a pleasant, neutral, nutty flavor to them. Slather them in powdered ranch or barbecue seasoning and it’s easy to imagine bags of them flying off the shelves in truck stops and convenience stores.
The dried larvae also have an advantage over other insect edibles — like, say, Mexico’s chapulines — in that they don’t really look like bugs. They have few identifiable buggy characteristics — no legs to get stuck in your teeth, no eyes to stare at you. It would be easy enough to mistake them for some sort of exotic grain.
Close to 2 billion people worldwide already include insects in their diets, according to the 2013 U.N. report. Insect-based snacks are commonly seen in open-air markets in places such as Thailand and China, for instance.
The practice hasn’t caught on in Europe or the United States, in part, because of long-standing cultural attitudes toward insects.
This is somewhat puzzling, considering many Westerners happily consume foods such as crab and lobster, which are really just giant sea bugs.
“I absolutely think there will be applications [for the soldier fly] in the human food market,” says Liz Koutsos. “The challenge is getting over the cringe factor.”
One potential path to human consumption is via insect-based protein powders, which can be mixed with other foods, thus lessening the ick factor. Several companies are already doing this with crickets.
“There’s been a lot of effort put into cricket flour or mealworms for protein ingredients for everything from pasta to cookies to chips,” Tomberlin said.
He expects soldier fly protein to follow a similar path. “When you walk in these facilities in the next 10 years, we’ll look back at this era and say we were just getting started.”
Given that South African startup, Gourmet Grubb, make its luxury ice cream with EntoMilk, a dairy alternative made from the larvae of the black soldier fly, that day may come even sooner than you might expect!