This blog is based on findings from a research project conducted by the 71point4 team to understand the opportunity to support livelihoods through black soldier fly farming in small-scale, low-tech operations in South Africa. You can read about the project here.
The black soldier fly (Hermetia illucens) is receiving increasing attention as both an organic waste management solution as well as an eco-friendly product alternative with various applications, most notably animal feed.
In its adult form, the black solider fly, otherwise known as BSF, is a long-bodied insect whose sole objective is to mate and lay eggs. Unlike the regular housefly, the black soldier fly lacks mouthparts and so does not seek out food or transmit diseases. Instead, the insect only consumes food during the larval phase.
BSF larvae are voracious consumers of organic matter, capable of eating double their body mass on a daily basis. Further, the larvae can digest a wide range of organics and are thus considered a potential candidate to manage organic waste. This is an attractive attribute in a country like South Africa that generates a staggering volume of food waste and where landfills are running out of space. In the Western Cape, for instance, the government has implemented a 100% ban on organic waste sent to landfill by 2027.
Larvae diets can include anything from primary production waste generated at the farm, to organic household and restaurant waste, waste generated by food processing companies as well as meat waste and even faeces. Through a process called bioconversion, the larvae’s digestive process converts organic matter into its own body mass. While BSF larvae are not the only insects capable of organic matter bioconversion, the bioconversion process of BSF larvae is superior in several ways. BSF larvae gain body mass more efficiently than other insects meaning that it takes less organic matter to produce an additional unit of body mass for BSF larvae. This is important because higher body mass equates to greater value – more on that below. Furthermore, the BSF larvae’s digestive process is capable of neutralising certain pathogens and breaking down pharmaceuticals, effectively cleaning the consumed waste and preventing the transfer of these substances to downstream products.
Once the larvae are introduced to the organic waste, they feed for approximately two weeks, reducing the volume of organic waste (use case 1: waste reduction) and growing body mass (use case 2: building product value) until they are ready to be harvested.
The main product application for mature BSF larvae is animal feed. The larvae can be fed in either live or dried form to a range of livestock including poultry and pigs, as well as fish, reptiles and wild birds. The larvae have a favourable nutrient profile, being high in protein and fats and offering antimicrobial properties that boost gut health in animals that consume them. BSF larvae-based animal feed is also more environmentally friendly to produce than typical soy-based animal feeds. In addition, frass (a mixture of BSF larvae faeces, discarded exoskeletons and waste residue) is gaining popularity as an organic fertilizer. Other applications include dried BSF larvae for human consumption and extraction of the larvae components – oil and chitin (larvae skeleton) – for use in pharmaceuticals or as an additive to animal feed.
An additional advantage of BSF larvae farming compared to other waste-to-value solutions such as pyrolysis is that processing facilities can scale to the volume of organic waste available. Micro operations using plastic containers can process a few kilograms of waste per day, while large industrial scale operations can process up to 100 tonnes of waste per day.
“So, what’s the catch?”, we wondered as we progressed through our research project into the opportunity for black soldier fly farming in South Africa.
Well, the industry is in the nascent phase. While a number of black soldier fly companies have already established operations in South Africa, new entrants into the space must grapple with a few key issues:
1. Organic waste is heavy and costly to transport. It is not practical to utilize waste sources that are located far away from the black soldier fly facility. Instead, the BSF facility should be located as close as possible to the waste source (ideally on-site). This might not pose a problem in rural or industrial settings, but the risk of a worm breakout or a malfunction at a processing plant containing tons of organic waste might be a concern in higher density, urban areas.
2. Patient capital is required to help set up small-scale, decentralised BSF facilities. Container-based BSF facilities treating between 0.5 to 1 tonnes of food waste per day are currently being tested in other markets and several local BSF players are interested in its potential to solve the problem of transporting organic waste off-site. However, pilots are required to test the commercial viability of these solutions. Practical considerations include the geographic location selected for the BSF facility; BSF larvae require a warm, humid environment provided either by ambient conditions or artificial climate control within the facility. Artificial climate control comes with capital and operational costs that may compromise the viability of small-scale facilities, and an alternative power source may be required to guard against loadshedding.
3. Legislation governing the use of insect protein as animal feed varies across countries and is evolving. This legislation typically governs the types of waste that can be fed to larvae intended for animal feed, and the types of animals that the larvae can be fed to. South African legislation however is underdeveloped and does not yet fully recognize insects as animal feed. While dried larvae are considered animal feed and thus can only be legally sold if the product is registered, live larvae are not considered animal feed and so no restrictions apply. This may change in future as the recently formed industry body, the Southern African Mass Insect Rearing Organisation (SAMIRO), is currently developing guidelines based on best practice and international experience. Given the particular application of legislation to black soldier fly products intended to enter the food chain, new entrants must first define their intended end product. Some waste streams may not be suitable where the product is part of the human food chain. In certain cases heat can be used to reduce the risk of pathogen transfer, either by heating the waste prior to introducing BSF, or by drying the mature larvae after harvesting.
4. A final challenge relates to market adoption. Animal feed supply chains are well entrenched, and farmers are familiar with existing products. The successful introduction of a new product – albeit it with demonstrable advantages – will require a concerted effort.
Despite these challenges, our money (metaphorically) is on the fly. While it may take some tweaking before profitable business models emerge, once they do, the invisible hand can tackle a huge environmental problem. Seriously no BS here.