Why farm black soldier fly?
Hermetia illucens also known as the black soldier fly (BSF).
Introduction
The black soldier fly (BSF), scientifically known as Hermetia illucens, is a common and widespread fly of the family Stratiomyidae. The insect species has increasingly been gaining significant attention due to its unique biological characteristics and potential applications in various fields including waste management, animal feed production and even as food for humans. Black soldier fly are considered by many to be nature’s apex recycler – a tiny yet robust insect perfectly designed to rapidly turn any organic waste into valuable protein. It’s for this reason black soldier fly is currently the most widely farmed insect species worldwide.
The species is native to the Neotropical region, but in recent decades has spread across all continents except Antartica, becoming virtually cosmopolitan and can commonly be found in Europe as far north as France.
The black soldier fly is aptly named for its dark, metallic appearance, with a shiny black exoskeleton that distinguishes it from other fly species. It typically measures around 16 to 18 millimetres in length as an adult, with large, membranous wings that enable it to fly short distances. Its body is segmented, featuring three distinct regions: the head, thorax, and abdomen. The head contains compound eyes, antennae, and mouthparts adapted for feeding. The thorax houses the muscles responsible for flight, while the abdomen harbours the digestive system and reproductive organs.
Upon close inspection, the black soldier fly has only one pair of fully formed wings much like other insects of the order name “Diptera”, which literally means “two wings” in Ancient Greek. In place of hindwings, it has a pair of modified wings called halteres which function as gyroscopes to detect body rotation, and the fly uses them to make corrections and re-stabilise itself during flight.
Another striking feature of the black soldier fly is the transparent “windows” found on its abdomen. It’s thought that this helps to complete their disguise as an organ pipe mud dauber wasp in a form of Batesian mimicry. From a distance, the see-through abdominal segments give the illusion of a narrow wasp-like waist. By mimicking the appearance of an aggressive predatory species, the harmless black soldier fly can successfully deter unwanted attention from other predators.
A four-stage life cycle
The life cycle of the black soldier fly consists of four main stages: egg, larvae, pupae, and adult fly. The process begins when adult female flies lay eggs in decaying organic matter, such as compost heaps, manure, or food waste. Each female can lay hundreds of eggs during her lifespan, typically depositing them in clusters.
Upon hatching, the larvae emerge as small and creamy-white in colour and have voracious appetites. They feed ravenously on organic material, breaking it down through microbial action and their own digestive enzymes. This feeding behaviour not only facilitates the decomposition process but also allows the larvae to accumulate nutrients essential for their growth and development.
Black soldier fly larvae in palm of hand. Photo: Entocycle.
As the larvae mature, they undergo several molts, shedding their exoskeletons to accommodate their increasing size. This growth phase lasts approximately two weeks, after which the larvae enter the pupal stage. During pupation, the larvae cease feeding and become immobile as they undergo metamorphosis. Within a few days, the pupae transform into adult flies, emerging from their pupal cases ready to reproduce and continue the life cycle.
The benefits of farming black soldier fly
Black soldier fly larvae offer a multitude of benefits that make them an excellent protein source for farmed animals and pets. Their ability to convert organic waste into high-quality protein, rapid growth rate, balanced nutritional composition, low environmental footprint, and contribution to the circular economy all contribute to their status as the perfect protein source.
An ideal protein source
The nutrient-rich larvae produced during the bioconversion process can be harvested and utilised as high-protein feed ingredients for livestock, poultry, aquaculture, and even pets. Studies have shown that black soldier fly larvae exhibit excellent growth rates and nutritional profiles, making them a cost-effective and low-carbon source of animal feed compared to conventional feed sources such as soybean meal or fishmeal. The dry weight of black soldier fly larvae contains up to 55% crude protein, up to 35% lipids and has an amino acid profile that is similar to that of fishmeal. In 2019, The British Veterinary Association (BVA) said some insect-based foods may be better for pets than prime steak.
Non-disease
One of the most significant advantages of farming black soldier flies rather than other insects is its inherent ability to prevent the spread of disease. Unlike crickets, which have been associated with the transmission of zoonotic diseases such as salmonella, black soldier flies pose minimal risk of disease transmission to humans or livestock. Their natural biology and feeding habits reduce the likelihood of harbouring and spreading pathogens, making black soldier fly larvae a safer option for use in feed and food production. Additionally, black soldier fly larvae have antimicrobial properties that help prevent the growth of pathogens in their environment.
Transform waste into resource
Black soldier fly larvae are not particularly fussy about what they eat, and so unlike crickets or mealworms, can be used to process a wide range of organic waste streams, including food waste such as spent beer grains or vegetable peelings, animal manure, and agricultural residues. This characteristic makes them excellent bioconverters, transforming organic waste that would otherwise go to landfills or into anaerobic digestion into valuable protein. By utilising black soldier fly larvae, the food and agricultural industry can significantly reduce waste and minimise its environmental impact.
Incredibly fast-growing
Black soldier fly larvae have an impressive growth rate, gaining between 5,000 – 7,000 times their initial body weight and reaching their full size within a short period, typically just 10 to 14 days. This rapid growth translates into a high production yield, allowing farm operators to obtain substantial amounts of protein in a relatively short time frame. Compared to traditional protein sources, such as soybeans or fishmeal, black soldier fly larvae (BSFL) can be produced at a significantly faster rate, using less land and resources, making them a highly efficient and scalable solution for protein production.
Black soldier fly pupae. Photo: Entocycle
Current legislation
The legislative landscape surrounding black soldier fly farming varies across different regions, posing challenges and opportunities for stakeholders in the industry.
The EU – Aquaculture, poultry, pig and pets
In 2017, the European Commission passed legislation authorising the use of processed animal protein from seven species of insects, including black soldier fly (Hermetia illucens), as feed in aquaculture.
In 2021, the European Commission amended the Feed Ban Rules to permit the use of processed insect protein in poultry and pig feed under the same conditions as permitted for feeding aquaculture animals. The legislation acknowledges that poultry are insectivorous animals and porcine animals are omnivorous, and as such there are no concerns with insect protein as a feed material.
The UK – Aquaculture and pets
In the United Kingdom, the regulatory framework for BSF farming primarily falls under the jurisdiction of several government agencies, including the Department for Environment, Food & Rural Affairs (DEFRA), the Food Standards Agency (FSA), and the Animal and Plant Health Agency (APHA).
In 2017, and with the UK still part of the EU, the European Commission legislation was adopted as part of GB domestic legislation to permit black soldier fly as feed in aquaculture.
The European Commission’s amendment to the Feed Ban Rules does not, however, take effect in GB as it was introduced after 31 December 2020, which means the feeding of insect protein to chicken and pigs remains prohibited in the UK (except as live larvae in chicken feed). It is expected, however, that GB legislation will be amended in the near future to permit the use of processed insect protein in poultry and pig feed.
Insects, including black soldier fly, can be used to make processed pet food under UK law, provided they don’t carry diseases that can be passed on to humans or animals.
In terms of permitted feedstocks for breeding black soldier fly in the UK, only materials that contain products of non-animal origin (such as vegetal matter, residue from fruit and vegetable processing and brewery by-products and some animal origin products such as milk) are allowed.
For more information regarding EU and UK legislation visit:
https://ipiff.org/insects-eu-legislation-general/
https://www.michelmores.com/agriculture-insight/insect-protein-animal-feed/