The larvae of adult black soldier flies can turn food waste into sustainable protein with minimal methane gas emissions.
In Sydney, Australia, in the basement of an inner-city high-rise, lives a mass of unexpected inhabitants: millions of maggots. The insects are far from unwelcome. They are there to feast on the food waste generated by the building's human residents.
Goterra, the start-up that installed the maggots in the building in December, belongs to the rapidly expanding insect agriculture industry, which is experiencing a surge of investment worldwide.
The maggots – the larvae of the black soldier fly – are voracious, unfussy eaters. As adult flies, they don't eat, so the young fatten up swiftly on whatever they can get. Goterra's basement colony can munch through 5 metric tons of waste in a day.
"Maggots are nature's cleaners," says Bob Gordon, Head of Growth at Goterra. "They're a great tool to manage waste streams."
Their capacity to consume presents a neat response to the problem of food waste, which contributes up to 8% of global greenhouse gas emissions each year as it rots in landfill.
"The maggots eat the food fairly fresh," Gordon says. "So, there's minimal degradation and you don't get those methane emissions."
Alongside their ability to devour waste, the soldier fly larvae hold further agricultural promise: they yield an incredibly efficient protein. After the maggots have binged for about 12 days, Goterra harvests and processes them into a protein-rich livestock feed. Their excrement, known as frass, is also collected and turned into soil conditioner.
"We are producing protein in a basement," says Gordon. "It's urban farming – really sustainable, urban farming."
Goterra's module in the basement at Barangaroo, Sydney.
Supplied by Goterra
Goterra's founder Olympia Yarger started producing the insects in "buckets in her backyard" in 2016. Today, Goterra has a large-scale processing plant and has developed proprietary modules – in shipping containers – that use robotics to manage the larvae.
The modules have been installed on site at municipal buildings, hospitals, supermarkets, several McDonald's restaurants, and a range of smaller enterprises in Australia. Users pay a subscription fee and simply pour in the waste; Goterra visits once a fortnight to harvest the bugs.
Insect agriculture is well established outside of the West, and the practice is gaining traction around the world. China has mega-facilities that can process hundreds of tons of waste in a day. In Kenya, a program recently trained 2000 farmers in soldier fly farming to boost their economic security. French biotech company InnovaFeed, in partnership with US agricultural heavyweight ADM, plans to build "the world's largest insect protein facility" in Illinois this year.
"The [maggots] are science fiction on earth. Watching them work is awe-inspiring."
But the concept is still not to everyone's taste.
"This is still a topic that I say is a bit like black liquorice – people tend to either really like it or really don't," says Wendy Lu McGill, Communications Director at the North American Coalition of Insect Agriculture (NACIA).
Formed in 2016, NACIA now has over 100 members – including researchers and commercial producers of black soldier flies, meal worms and crickets.
McGill says there have been a few iterations of insect agriculture in the US – beginning with worms produced for bait after World War II then shifting to food for exotic pets. The current focus – "insects as food and feed" – took root about a decade ago, with the establishment of the first commercial farms for this purpose.
"We're starting to see more expansion in the U.S. and a lot of the larger investments have been for black soldier fly producers," McGill says. "They tend to have larger facilities and the animal feed market they're looking at is potentially quite large."
InnovaFeed's Illinois facility is set to produce 60,000 metric tons of animal feed protein per year.
"They'll be trying to employ many different circular principles," McGill says of the project. "For example, the heat from the feed factory – the excess heat that would normally just be vented – will be used to heat the other side that's raising the black soldier fly."
Although commercial applications have started to flourish recently, scientific knowledge of the black soldier fly's potential has existed for decades.
Dr. Jeffery Tomberlin, an entomologist at Texas A&M University, has been studying the insect for over 20 years, contributing to key technologies used in the industry. He also founded Evo, a black soldier fly company in Texas, which feeds its larvae the waste from a local bakery and distillery.
"They are science fiction on earth," he says of the maggots. "Watching them work is awe-inspiring."
Tomberlin says fly farms can work effectively at different scales, and present possibilities for non-Western countries to shift towards "commodity independence."
"You don't have to have millions of dollars invested to be successful in producing this insect," he says. "[A farm] can be as simple as an open barn along the equator to a 30,000 square-foot indoor facility in the Netherlands."
As the world's population balloons, food insecurity is an increasing concern. By 2050, the UN predicts that to feed our projected population we will need to ramp up food production by at least 60%. Insect agriculture, which uses very little land and water compared to traditional livestock farming, could play a key role.
Insects may become more common human food, but the current commercial focus is animal feed. Aquaculture is a key market, with insects presenting an alternative to fish meal derived from over-exploited stocks. Insect meal is also increasingly popular in pet food, particularly in Europe.
While recent investment has been strong – NACIA says 2020 was the best year yet – reaching a scale that can match existing agricultural industries and providing a competitive price point are still hurdles for insect agriculture.
But COVID-19 has strengthened the argument for new agricultural approaches, such as the decentralized, indoor systems and circular principles employed by insect farms.
"This has given the world a preview – which no one wanted – of [future] supply chain disruptions," says McGill.
As the industry works to meet demand, Tomberlin predicts diversification and product innovation: "I think food science is going to play a big part in that. They can take an insect and create ice cream." (Dried soldier fly larvae "taste kind of like popcorn," if you were wondering.)
Tomberlin says the insects could even become an interplanetary protein source: "I do believe in that. I mean, if we're going to colonize other planets, we need to be sustainable."
But he issues a word of caution about the industry growing too big, too fast: "I think we as an industry need to be very careful of how we harness and apply [our knowledge]. The black soldier fly is considered the crown jewel today, but if it's mismanaged, it can be relegated back to a past."
Goterra's Gordon also warns against rushing into mass production: "If you're just replacing big intensive animal agriculture with big intensive animal agriculture with more efficient animals, then what's the change you're really effecting?"
But he expects the industry will continue its rise though the next decade, and Goterra – fuelled by recent $8 million Series A funding – plans to expand internationally this year.
"Within 10 years' time, I would like to see the vast majority of our unavoidable food waste being used to produce maggots to go into a protein application," Gordon says.
"There's no lack of demand. And there's no lack of food waste."
Sarah Watts's son Henry was born with spina bifida and can't stand or walk without assistance.
When our son Henry, now six, was diagnosed with spina bifida at his 20-week ultrasound, my husband and I were in shock. It took us more than a few minutes to understand what the doctor was telling us.
When Henry was diagnosed in 2012, postnatal surgery was still the standard of care – but that was about to change.
Neither of us had any family history of birth defects. Our fifteen-month-old daughter, June, was in perfect health.
But more than that, spina bifida – a malformation of the neural tube that eventually becomes the baby's spine – is woefully complex. The defect, the doctor explained, was essentially a hole in Henry's lower spine from which his spinal nerves were protruding – and because they were exposed to my amniotic fluid, those nerves were already permanently damaged. After birth, doctors could push the nerves back into his body and sew up the hole, but he would likely experience some level of paralysis, bladder and bowel dysfunction, and a buildup of cerebrospinal fluid that would require a surgical implant called a shunt to correct. The damage was devastating – and irreversible.
We returned home with June and spent the next few days cycling between disbelief and total despair. But within a week, the maternal-fetal medicine specialist who diagnosed Henry called us up and gave us the first real optimism we had felt in days: There was a new, experimental surgery for spina bifida that was available in just a handful of hospitals around the country. Rather than waiting until birth to repair the baby's defect, some doctors were now trying out a prenatal repair, operating on the baby via c-section, closing the defect, and then keeping the mother on strict bedrest until it was time for the baby to be delivered, just before term.
This new surgery carried risks, he told us – but if it went well, there was a chance Henry wouldn't need a shunt. And because repairing the defect during my pregnancy meant the spinal nerves were exposed for a shorter amount of time, that meant we'd be preventing nerve damage – and less nerve damage meant that there was a chance he'd be able to walk.
Did we want in? the doctor asked.
Had I known more about spina bifida and the history of its treatment, this surgery would have seemed even more miraculous. Not too long ago, the standard of care for babies born with spina bifida was to simply let them die without medical treatment. In fact, it wasn't until the early 1950s that doctors even attempted to surgically repair the baby's defect at all, instead of opting to let the more severe cases die of meningitis from their open wound. (Babies who had closed spina bifida – a spinal defect covered by skin – sometimes survived past infancy, but rarely into adulthood).
But in the 1960s and 1970s, as more doctors started repairing defects and the shunting technology improved, patients with spina bifida began to survive past infancy. When catheterization was introduced, spina bifida patients who had urinary dysfunction, as is common, were able to preserve their renal function into adulthood, and they began living even longer. Within a few decades, spina bifida was no longer considered a death sentence; people were living fuller, happier lives.
When Henry was diagnosed in 2012, postnatal surgery was still the standard of care – but that was about to change. The first major clinical trial for prenatal surgery and spina bifida, called Management of Myelomeningocele (MOMS) had just concluded, and its objective was to see whether repairing the baby's defect in utero would be beneficial. In the trial, doctors assigned eligible women to undergo prenatal surgery in the second trimester of their pregnancies and then followed up with their children throughout the first 30 months of the child's life.
The results were groundbreaking: Not only did the children in the surgery group perform better on motor skills and cognitive tests than did patients in the control group, only 40 percent of patients ended up needing shunts compared to 80 percent of patients who had postnatal surgery. The results were so overwhelmingly positive that the trial was discontinued early (and is now, happily, the medical standard of care). Our doctor relayed this information to us over the phone, breathless, and left my husband and me to make our decision.
After a few days of consideration, and despite the benefits, my husband and I actually ended up opting for the postnatal surgery instead. Prenatal surgery, although miraculous, would have required extensive travel for us, as well as giving birth in a city thousands of miles from home with no one to watch our toddler while my husband worked and I recovered. But other parents I met online throughout our pregnancy did end up choosing prenatal surgery for their children – and the majority of them now walk with little assistance and only a few require shunting.
Even more amazing to me is that now – seven years after Henry's diagnosis, and not quite a decade since the landmark MOMS trial – the standard of care could be about to change yet again.
Regardless of whether they have postnatal or prenatal surgery, most kids with spina bifida still experience some level of paralysis and rely on wheelchairs and walkers to move around. Now, researchers at UC Davis want to augment the fetal surgery with a stem cell treatment, using human placenta-derived mesenchymal stromal cells (PMSCs) and affixing them to a cellular scaffold on the baby's defect, which not only protects the spinal cord from further damage but actually encourages cellular regeneration as well.
The hope is that this treatment will restore gross motor function after the baby is born – and so far, in animal trials, that's exactly what's happening. Fetal sheep, who were induced with spinal cord injuries in utero, were born with complete motor function after receiving prenatal surgery and PMSCs. In 2017, a pair of bulldogs born with spina bifida received the stem cell treatment a few weeks after birth – and two months after surgery, both dogs could run and play freely, whereas before they had dragged their hind legs on the ground behind them. UC Davis researchers hope to bring this treatment into human clinical trials within the next year.
A century ago, a diagnosis of spina bifida meant almost certain death. Today, most children with spina bifida live into adulthood, albeit with significant disabilities. But thanks to research and innovation, it's entirely possible that within my lifetime – and certainly within Henry's – for the first time in human history, the disabilities associated with spina bifida could be a thing of the past.