/ 19 April 2023

How the black soldier fly converts organic waste into animal feed

Copy Of Breeding
The black soldier fly can be beneficial both economically and environmentally because they are a good source of oil and protein, according to the University of Florida. Photo: Supplied

When one thinks of flies, it’s about how annoying they are and how they spread germs. The black soldier fly, also known as Hermetia illucens, is a little more useful than the regular house fly. 

But the black soldier fly can be beneficial both economically and environmentally because they are a good source of oil and protein, according to the University of Florida. The larvae can turn organic waste into a rich fertiliser — which is exactly what a company in Knysna is using them to do.

The Mail & Guardian spoke to Maya Zaken, the head of business developments, marketing and fundraising at Philafeed, which has been “farming” with the black soldier fly since 2022. 

M&G: Tell us how Philafeed started. 

Zaken: In 2019, I was completing my bachelor degree in economics when I started volunteering with Voice to Echo church in the Kya Sands informal settlement. With my knowledge gained in my development economics course, I turned to agriculture as a means of social and economic development. 

After two years doing different courses, gaining different experience, meeting people in the industry, one of my colleagues called me to find out if I knew about black soldier flies. Immediately I fell in love. I called Jason Fine, now the head of business operations at Philafeed, who at the time was leaving his career in IT wanting to find a waste management business to work with. Black soldier flies was his answer. 

They ticked all our boxes and would be the vehicle that could allow us to drive all kinds of development and system change.

What are the objectives of Philafeed?

Philafeed’s goal is to contribute to the development of our country and the regeneration of our planet through circular waste management practices, which is the use of products that become waste and sustainably used by people again. 

We aim to enhance the effect of the black soldier fly by creating a low carbon, low budget model that can be replicated in numerous areas, closing multiple community food loops. 

The way I like to explain what closing multiple community food loops are, is by saying that everything in nature goes back into nature, so like the idea of composting, you use whatever comes out on the other side to put it back into a system. This localised approach can contribute to the development of resilient and sustainable local food systems.

Tell us about the process of converting organic waste to sustainable animal feed using the black soldier fly.

The process begins once we collect organic waste from restaurants, breweries and other waste sources in Knysna. When we speak of organic waste we are referring to food waste. We remove any inorganic material such as cans, glass and metal, reduce the particle size of the food waste so the black soldier fly can eat more efficiently.

We add the waste to a tray, where we then add neonates — 5 day old baby larvae — that we order from established black soldier fly companies. Currently we have a small nursery where we are gaining the technical skills to breed our own larvae.

The black soldier fly immediately starts eating the waste. After about 12 days the tray transforms into a mixture of full grown larvae and frass — insect waste (residue). Fun fact: larvae eat double their body mass on a daily basis. At this point we harvest most of the larvae to sell to farmers, homesteads as well as pet owners, and the other proportiongoes into our small nursery into pupation where it uses up all of the energy it stored during its feeding stage to transform into black soldier fly. 

The fly lives for about six days where it drinks a bit, mates and ultimately brings the next generation of natural waste processors into existence. After being incubated and spending five days in the nursery, they will be transferred to a tray where the cycle is continued.

What is frass?

Frass is the excrement or waste material produced by insects, particularly the larvae. Frass is rich in nutrients and can be used as a valuable resource in various applications, including organic fertiliser, vermiculture — which is turning organic waste into your own fertiliser using worms — pest control as it has insecticidal properties that can be used as a natural pesticide or repellent against certain pests in agriculture and gardening. It can be used as a non-toxic and environmentally friendly alternative to chemical pesticides. It has many benefits enhancing soil health, and resilience, improving growth of plants.

Frass from black soldier flies high in carbon improving soils water holding capacity and

contributing to carbon sequestration in soil. This means storing carbon in soil so it does not enter the atmosphere, but also ensuring that the plant uses its resources more efficiently and that it is able to store nutrients for longer. This makes frass a promising resource for sustainable agriculture and environmental management.

How has waste collection and use benefited the environment?

It offers several environmental benefits, including waste reduction, nutrient recycling, greenhouse gas reduction, sustainable protein production, reduced chemical use, and localised food systems, making it an environmentally-friendly and sustainable solution for managing organic waste.

Our business is focused on improving urban waste management systems, which currently rely on outdated landfill practices that release significant amounts of greenhouse gases, including methane, into the environment, posing a major threat to our health and the health of our planet.

By diverting large amounts of waste from landfills, we believe we can have a significant effect on climate change by reducing methane emissions, which are 78% more potent than carbon dioxide.

Black soldier fly technology also provides us with the opportunity to close loop supply chains by minimising the use of virgin materials. Instead of relying on farming livestock for protein, we use existing resources like organic food waste, reducing the demand for alternative resources like soya and fishmeal that rely on extractive processes, which can decrease natural carbon sinks. In this way, we create two sustainable products — insect protein and their byproduct, frass — that allow us to alleviate pressure on land and ocean resources while also increasing biodiversity.

Why the black soldier fly specifically? 

The black soldier fly gives us a glimpse of how we view waste and resources in our world. Instead of seeing waste as a problem to be disposed of, the fly steers us in a direction where waste is seen as a valuable resource.

This transformation of waste into a valuable resource not only reduces the burden on landfills and minimises environmental pollution, but also creates a circular economy where waste becomes a valuable input for production. 

The larvae are also protein-rich and can be used as a nutrient-dense feed for animals, reducing the dependence on traditional protein sources that may have environmental and social impacts, such as fish meal or soybean meal. 

In summary, the black soldier fly represents a vision of a world where waste is seen as a resource, and abundance can be created through sustainable and innovative solutions. 

Are they native to South Africa?

The black soldier fly is not native to South Africa. It is believed to have originated in the tropical and subtropical regions of the Americas. But it has been introduced to various parts of the world, including South Africa, probably through human activities such as trade and transportation. The exact timeline of how and when it arrived in South Africa is not clear.

What are you hoping to achieve with this black soldier fly project? 

We aim to show that it is possible to achieve both financial sustainability and positive social and environmental impacts through our business model.

We aspire to contribute to the creation of local and sustainable systems that support not only the current generation but also future generations. We believe that local food systems and circular economy approaches, where waste is seen as a resource, can play a critical role in building resilient communities and supporting long-term sustainability.

Our vision is to not only address pressing challenges such as waste management and food security, but also to promote community empowerment, economic development and environmental conservation.

Lesego Chepape is a climate reporting fellow, funded by the Open Society Foundation for South Africa