What is the black soldier fly?
The black soldier fly (Hermetia illucens) is a common and widespread insect, native to the tropical Americas and currently found on all continents (F(Figigurre 1). Its voracious larvae feed on a wide range of organic materials, from manure to food scraps, and efficiently convert biomass into high-quality proteins, lipids, and macro/micronutrients alongside their feces, or frass, a microbe and nutrient-rich residue.
Why farm BSFL?
The black soldier fly (BSF) is a versatile, nature-based solution for a more circular, sustainable food system. Black soldier fly larvae (BSFL) are key cogs in a circular economy, closing the loop through recapturing and reintegrating wasted nutrients into the food system.
Black soldier fly larvae (BSFL) have proven to be remarkably effective at consuming a wide range of organic materials and converting them into their protein- and lipid-rich biomass.
Put simply, BSFL turn organics wastes into two primary products: animal feed (larvae) and soil biofertilizer (insect excrement and exoskeletons).
Soil Health
Healthy soil is a highly biodiverse living environment of microbes, fungi, invertebrates, and more. Soils play a critical role in nutrient and element cycling, carbon sequestration, and the physical and nutrient support of plants. Conventional agriculture negatively affects long-term soil health and on-farm practices (eg. tillage, monocropping) resulting in further nutrient depletion, reduction of organic matter, erosion, and harmful runoff into waterways. The application of chemical fertilizers and pesticides can damage soil biodiversity and microbial communities, disrupting many basic functions of a healthy soil13 and can account for 20% of overall GHG emissions.
The primary byproduct of BSFL production is frass: a mixture of feces, shed exoskeletons, and substrate residue. Frass is not only an effective fertilizer, rich in nitrogen, phosphorus, potassium(NPK), but is alive with a diverse and prolific microbial community, as substrate is modified by insect gut microbiota during digestion.14 Frass also contains organic matter, an essential component for increasing soil water retention and more broadly, a key element supporting healthy soil rehabilitation and reduction in chemical fertilizer use (Figure 2).
Animal Feed
Insects are a natural part of the diet for many fish species, poultry, swine, and even dogs and cats. Animal production volumes have consistently increased since the 1960s and continue to grow to meet increasing demand (Figure 3).
Rich in protein, fat, vitamins and minerals, the nutrient profile of BSFL is aligned with the dietary requirements of commercially important livestock species and pets. In addition, BSFL are loaded with bioactive compounds, such as antimicrobial peptides, and their inclusion in diets has been shown to have significant health and animal welfare benefits. Plant-based ingredients, like soybean meal, are known to contain antinutritional factors and cause gut inflammation in fish, poultry and swine. The use of BSFL ingredients in animal feeds partially or fully replaces ingredients like soybean meal and fishmeal, thus avoiding the negative health and/or environmental impacts associated with these ingredients. Impact footprints vary depending on the ingredient format and production methodology, but life cycle assessments have found ingredients derived from BSFL reared on waste streams to be less resource-intensive with smaller land use, water use, and carbon footprints than traditional ingredients.
How to DIY farm BSFL in your Backyard
Black Soldier Fly Life Cycle
From Egg to Maggot
Embarking on their journey as tiny eggs, Black Soldier Fly Larvae emerge into a world shared with nearly 500 siblings, each maggot measuring a mere 1 mm at birth. Over a swift two-week period, these larvae undergo multiple "instars," akin to phases of larval growth. While the initial instars are just 1 mm in size, the final instar reaches a substantial ¾" to 1" in length. This rapid growth, outpacing even redworms, transforms Black Soldier Fly Larvae into remarkably efficient composters when working collectively.
Maggot to Pupa
After transitioning into the final instar phase, the maggot consumes just enough to grow larger and store energy as fat for the upcoming pupa stage. Seeking a dry, cool, and dark area outside the compost pile, the larvae undergo metamorphosis. In about two weeks, an adult fly emerges with a darker and more rigid exoskeleton.
Pupa to Adult Flies
Distinguished by an elongated body and a clear section on their abdomen, adult black soldier flies deviate from common houseflies. This unique appearance, mimicking wasps, serves as a potential deterrent to predators. Despite resembling wasps, black soldier flies exhibit docile behavior and slow movement. With a lifespan of only 4-5 days, these flies carefully time their mating rituals for reproduction.
Mating to Eggs
Engaging in ritualistic mating behavior, black soldier flies soar high above or near compost sources. Females dart, and males must adeptly intercept and initiate copulation. Remaining "butt-to-butt," the male transfers sperm to the female, fertilizing eggs. Females prefer depositing up to 500 eggs on surfaces like wood, cardboard, and corncobs, kickstarting a new generation.
Setting Up a BSFL Composting Bin
Designing the Perfect BSFL Bin
Optimal for harvesting mature larvae, the ideal black soldier fly larvae composting bin features a square bottom with sides forming small ramps. The angle of the sides, slightly below 45°, allows black soldier flies to climb out when ready. Attach a PVC half-pipe with holes for easy worm collection, promoting self-harvesting. Adding new compostable materials on top reduces volume, and rotating compost bins ensures a continuous cycle for prolific compost production.
What to Compost (BSFL Food Supply)
BSFL's Remarkable Appetite
Thriving on a diverse range of organic, energy-rich substances, black soldier fly larvae are exceptionally versatile. Unlike redworms, BSFL can handle various kitchen scraps, provided they are pesticide-free. On a larger scale, farmers successfully use BSFL to compost agricultural wastes, converting manure into nutrient-dense compost.
Creating an Environment for BSFL
Creating an Environment for BSFL
Creating the perfect environment for Black Soldier Fly Larvae (BSFL) requires a well-designed composting bin. Here's a step-by-step guide to help you set up an effective BSFL composting system in your own backyard:
1. Selecting the Bin:
Choose a bin with a square bottom and sides that form small ramps. The square shape provides stability, while the ramps enable easy exit for mature black soldier flies when they are ready to pupate.
2. Angle of the Sides:
Ensure that the angle of the sides is slightly less than 45°. This specific angle allows black soldier flies to climb out of the compost when they are prepared to enter the pupa stage.
3. PVC Half-Pipe Attachment:
Attach a PVC half-pipe cut lengthwise to the top of the bin. This serves as a collection mechanism for mature larvae. Cut holes at various intervals in the half-pipe to allow the larvae to fall through.
4. Collection Container:
Place a small bucket or jar below the holes in the half-pipe to collect the mature larvae. This setup facilitates self-harvesting as the worms naturally seek a safe place to pupate.
5. Adding Compostable Materials:
Begin by adding new compostable materials directly on top of the existing compost. The maggots will efficiently reduce the volume of the material. Continue this process until the bin starts to fill up.
6. Rotating Compost Bins:
To maintain a continuous cycle, allow black soldier flies to breed and lay eggs in the compost bin by screening it in (while meeting environmental variables). Once a bin is nearing full capacity, stop allowing new flies to access it. The remaining worms will continue composting until they reach full size. Start a second compost bin and repeat the cycle, alternating between bins.
7. Environmental Variables:
Monitor and control temperature, humidity, and lighting conditions. Black soldier flies thrive at around 86°F, with a humidity level of approximately 70%. Ensure UV light exposure, especially if composting indoors, using artificial light sources designed for black soldier fly production.
Setting up your BSFL composting bin with these considerations will not only maximize compost production but also make harvesting mature larvae a seamless process. Enjoy the benefits of efficient composting while contributing to a sustainable and eco-friendly backyard environment.
Adjusting Conditions
While black soldier flies thrive in the southern U.S., adjusting conditions is crucial elsewhere. Maintaining temperatures around 86°F, humidity at 70%, and providing UV light aids in efficient development. Composting indoors requires artificial UV light sources, and Evo Conversion Systems offers LED lights designed for optimal black soldier fly production.
Use Online Resources
This article covers the basics, but we’ve generalized things here. Make sure to monitor and adjust your unique ecosystem.
Our team recommends looking over EAWAG resources as a starting point - https://www.eawag.ch/en/department/sandec/projects/mswm/black-soldier-fly-biowaste-processing/ (and it might be all you need!) There’s a lot of information scattered about some of the long running forums. There are more specific design materials available online for those looking to integrate designs with their chicken coup of other small scale farming (e.g. aquaponics).
Here are some screenshots from a wikiHow article:
We also recommend Googling some videos (there are a few on YouTube) to obtain a visual understanding of the setups you can use in your backyard.
Ok, you've set up your backyard BSFL farm. Now what?
Utilizing Frass: The Gold from BSFL Compost
Maximizing Compost Benefits
BSFL frass is nutrient-dense and microbially active. The output will vary greatly depending on the feedstock provided to your BSFL. Careful monitoring and experimentation is best when applying frass.
There are several ways to utilize this frass-compost. Some online sources recommend decreasing the concentration of the frass to balance the nutrients and minerals.
Dried frass, frass "tea," and mixing with topsoil offer versatile options. Dried frass granules slowly release nutrients into the soil, while frass tea serves as a liquid nutrient broth. Mixing with topsoil creates an enriching planting mix for sustained plant growth.Here are a few ways it can be used:
Dried Frass: To enhance its usability and reduce concentration, consider drying out the compost and transforming it into dried frass. Once dried, the frass can be crushed or ground into small granules. These granules serve as a slow-release fertilizer when sprinkled on the soil surface. As you water the plants or when it rains, the nutrients leach gradually into the soil. It's advisable to start with a small test area, as the concentrated nature of dried frass can lead to "burning" signs on plant leaves if applied excessively. With dried frass, you can harness the potent nutrients of BSFL compost in a controlled and sustainable manner, promoting optimal plant growth while minimizing the risk of over-fertilization.
Frass “tea”: For an alternative and liquid application of the nutrient-rich benefits of Black Soldier Fly Larvae (BSFL) compost, consider creating frass "tea." This involves mixing the dried frass directly into water, resulting in a liquid nutrient broth that can be sprayed directly onto plants. The process may require some experimentation, as each batch of compost may impart different nutrient compositions to the tea. After letting the tea steep for a day or so, particulate matter can be filtered off, leaving a potent nutrient solution. Using a sprayer, you can evenly distribute the frass "tea" over large areas, providing plants with a direct and easily absorbable source of essential nutrients. Frass "tea" serves as a versatile solution, allowing you to tailor your application method based on the specific needs of your plants and promoting robust and healthy growth throughout your garden or landscape.
Mixing frass directly with topsoil: To further optimize the benefits of Black Soldier Fly Larvae (BSFL) compost, consider incorporating frass into your topsoil. This method involves blending the nutrient-dense frass with nutrient-poor soils, creating a well-balanced planting or potting mix. Begin with spent topsoil and add a generous amount of BSFL frass, combining the mixture thoroughly. For added aeration and moisture retention, incorporate some vermiculite into the blend. This resulting mixture forms an ideal environment for planting, ensuring a steady and prolonged release of nutrients to support plant growth over an extended period. Whether used for indoor plants or establishing new garden beds, the combination of frass and topsoil creates a nutrient-rich foundation, promoting flourishing vegetation and sustainable gardening practices.
Unlocking Nutrient-Rich Feed for Livestock: Black Soldier Fly Larvae as Animal Feed
Black Soldier Fly Larvae (BSFL) emerge as a strategic solution for enhancing the nutritional quality of animal feed, with specific inclusion rates offering tailored benefits for various livestock, including chickens, fish, and pigs. Farmers can implement precise ratios of BSFL in animal diets, capitalizing on their rich protein content, essential amino acids, and beneficial fats. The inclusion of BSFL becomes a targeted approach to address specific nutritional requirements, ensuring optimal health and growth for the animals.
Fine-Tuning Feed Conversion Ratios: Maximizing Efficiency
The key to unlocking the full potential of Black Soldier Fly Larvae as animal feed lies in fine-tuning inclusion rates to achieve maximum feed conversion ratios. By composting agricultural wastes like manure, spoiled feed, and harvest by-products with BSFL, farmers can customize feed formulations for chickens, fish, and pigs. This not only minimizes waste but also maximizes the nutritional value of the feed. Striking the right balance in inclusion rates allows farmers to harness the protein-rich composition of BSFL effectively. This targeted approach not only contributes to healthier and more efficiently raised livestock but also underscores the economic and environmental benefits of incorporating black soldier fly larvae into animal diets.
Embark on your journey to backyard black soldier fly farming and unlock the potential of these remarkable composters.
Citations
Purkayastha, D., & Sarkar, S. (2021). Sustainable Waste Management using black soldier fly larva: A Review. International Journal of Environmental Science and Technology, 1–26. https://doi.org/10.1007/s13762-021-03524-7
Lalander, C., Diener, S., Zurbrügg, C., & Vinnerås, B. (2019). Effects of feedstock on larval development and process efficiency in waste treatment with black soldier fly (Hermetia illucens). Journal of Cleaner Production, 208, 211–219. https://doi.org/10.1016/j.jclepro.2018.10.017
Fior Market Research LLP. (2021, June 2). Global Aquafeed Market is expected to reach USD 82.05 billion by 2028 : Fior Markets. GlobeNewswire News Room. Retrieved December 10, 2021, from https://www.globenewswire.com/news-release/2021/06/02/2240869/0/en/Global- Aquafeed-Market-Is-Expected-to-Reach-USD-82-05-billion-by-2028-Fior-Markets.html
Fior Market Research LLP. (2021, August 11). Global poultry feed market is expected to reach USD 313.11 billion by 2028 : Fior Markets. GlobeNewswire News Room. Retrieved December 10, 2021, from https://www.globenewswire.com/en/news-release/2021/08/11/2279116/0/en/Global- Poultry-Feed-Market-Is-Expected-to-Reach-USD-313-11-Billion-by-2028-Fior-Markets.html
Priyadarshana, M. K. C., Walpita, C. N., Naveenan, M., Magamage, M. P. S., & Ruwandeepika, H. A. D. (2021). Substitution of fishmeal with black soldier Fly Hermetia illucens linnaeus, 1758 larvae in finfish aquaculture – a review. Asian Fisheries Science, 34(2). https://doi.org/10.33997/j.afs.2021.34.2.001
Abd El-Hack, M., Shafi, M., Alghamdi, W., Abdelnour, S., Shehata, A., Noreldin, A., Ashour, E., Swelum, A., Al-Sagan, A., Alkhateeb, M., Taha, A., Abdel-Moneim, A.-M., Tufarelli, V., & Ragni, M. (2020). Black soldier fly (Hermetia illucens) meal as a promising feed ingredient for poultry: A comprehensive review. Agriculture, 10(8), 339. https://doi.org/10.3390/agriculture10080339
Barragan-Fonseca, K. B., Dicke, M., & van Loon, J. J. A. (2017). Nutritional value of the Black Soldier Fly (Hermetia illucens L.) and its suitability as animal feed – a review. Journal of Insects as Food and Feed, 3(2), 105–120. https://doi.org/10.3920/jiff2016.0055
Bosch, G., & Swanson, K. S. (2021). Effect of using insects as feed on animals: Pet dogs and cats. Journal of Insects as Food and Feed, 7(5), 795–805. https://doi.org/10.3920/jiff2020.0084
Freel, T. A., McComb, A., & Koutsos, E. A. (2021). Digestibility and safety of dry black soldier fly larvae meal and black soldier fly larvae oil in dogs. Journal of Animal Science, 99(3). https://doi.org/10.1093/jas/skab047
And, of course, our white papers: