Black Soldier Flies as Recyclers of Waste
By Harvey Black
If black soldier fly larvae could enter competitive eating contests, they would excel, especially when it comes to eating nasty stuff that we don’t want around or wouldn’t think of eating ourselves. Then, after the larvae had eaten, they could be recycled as feed for livestock, although the U.S. Food and Drug Administration currently prohibits that.
“FDA does not believe the use of insect protein ingredients can meet the standard for being GRAS (Generally Recognized as Safe),” wrote an FDA representative in an email. “As a result, such ingredients would appear to require food additive approval to be legally used as an ingredient in animal food. At this time, no food additive approvals have been issued for use of any type of insect material as an ingredient for any purpose in animal foods.” The European Union has similar restrictions.
However, if the regulations were to change, black soldier flies (Hermetia illucens) could be used on a large scale to dispose of organic wastes such as manure or offal, according to an article in Environmental Entomology called “Ability of Black Soldier Fly (Diptera: Stratiomyidae) Larvae to Recycle Food Waste.”
The article is timely, as it was published around the same time that an article in PLOS ONE found that the ability of crickets to convert plant matter into protein may be overestimated.
During research at the University of Windsor, the larvae waxed fat on diets of pig liver, pig manure, kitchen waste, and fish offal. The researchers housed larvae in small containers with six grams of each type of waste. Each day the remaining amount of food was weighed and another six grams were added. The feeding stopped when the larvae began to enter what is known as “the wandering stage,” signaling that they were getting ready to pupate.
As a control, the larvae were also fed a diet of nice, clean poultry feed, and the researchers compared the results with those of the of the organic-waste diets. They found that the larvae chowed down most on the food-waste and fish-offal diets.
“Larvae fed on fruit and vegetable waste consumed almost double the amount than those fed on standard poultry feed,” they wrote.
In fact, even the larvae that were fed a diet of pig manure ate more than those which received poultry feed.
“The total amount of manure waste reduction was 44% greater than that determined for the standard poultry feed,” they wrote.
“The study was the first to show that the insects can thrive on food waste,” said Dr. Jeffery Tomberlin of Texas A&M, one of the co-authors. “Insects are no different from most other animals. They need a balanced diet. What we found was food waste and fish offal probably contained the right amount of protein and carbohydrates to allow them successfully to develop.”
The study is an example of the surging interest in using black soldier fly larvae to recycle waste. According to Louis Sorkin, an entomologist at the American Museum of Natural History, the larvae are very efficient, and the droppings from the larvae can used as plant fertilizer.
DipTerra LLC, a firm based in Lake Oswego, OR, sells black soldier fly larvae for recycling organic waste. The firm’s head, Dr. Terry Green, claims that homeowners can easily use the larvae to degrade organic waste such as food scraps. He sees the value of the larvae in dollars and in environmental terms.
“The issue is, where can the black soldier fly be used most beneficially in both the environment and from an economic point of view?” he said.
In 2005, a team of scientists from the University of Georgia and North Carolina State University issued a report which studied how black soldier fly larvae might be used in recycling pig manure. They found that “Manure mass was reduced 56% while the concentrations of most elements and nutrients were reduced 40 to 55%. Nutrient analyses and feeding studies indicate that dried black soldier fly prepupae grown on swine manure solids have value as a feedstuff, particularly for aquaculture.”
Since that report was published, attempts have been made to use black soldier fly larvae to produce fish feed from organic waste, as this Scientific American video featuring Louis Sorkin shows.
Dr. Tomberlin noted that the larvae would not actually be fed directly to livestock. Instead, “a process would be used to pull the protein out.”
While there may be optimism for the use of black soldier fly larvae as a source of animal feed, Tomberlin points to some questions that have to be dealt with, in addition to the FDA’s stance on the matter. For one thing, the larvae would only be one part of a healthy diet for livestock.
“The insects need to be developed as part of a feed ingredient,” he said. “Chickens may need one thing, swine may need another, and the black soldier fly is not going to be the cornucopia of nutrients.”
Beyond the issue of nutrition, there are other questions that must be answered concerning the use of the larvae in animal feed. One is the safety of the product. Tomberlin said that feed products must not carry harmful microbes, and that no heavy metals — which can be harmful — should be fed to livestock.
Tomberlin emphasized that there are no data yet to show that the larvae can be turned into safe feed for livestock in the U.S. However, work is being done in China, where they are industrializing the process.
“I’ve seen facilities in China where they’re producing 20 tons of larvae a week,” he said. “It works. It’s amazing they’ve been able to industrialize it more than anyone else in the world. They use it for animal feed, they use it for aquaculture.”
Read more at:
– Ability of Black Soldier Fly (Diptera: Stratiomyidae) Larvae to Recycle Food Waste
Harvey Black is a freelance science writer. A long-time resident of Madison, Wisconsin, he has written for numerous publications including Environmental Health Perspectives, Scientific American Mind, New Scientist, The Scientist, and the Milwaukee Journal Sentinel.
Having spent a considerable number of years farming and researching how to economically scale up the production of BSF grown off of waste, I am curious as to how thoroughly the claim made by Dr. Tomberlin which you cite in your article regarding China being way ahead of the rest of the world in BSF farming technology, and Dr. Tomberlin having seen “facilities in China where they’re producing 20 tons of larvae a week”, was vetted.
Scaling up and maintaining BSF production at this level in processing waste would be a remarkable achievement.
Assuming all numbers cited are in wet weight units, the scale cited means the company would be harvesting approximately 2.9 tons prepupae/larvae per day. The best feed conversion ratios (ratio of dry weight larvae relative to dry weight waste used in growing the larvae) in farming BSF generally average around or just under 30% on a sustained basis. This means the company would need to process almost 30 tons of waste per day to sustain the growing larvae, and at a load rate of 5 kg per square meter in processing bins (typical), the total bin space dedicated for growing the larvae would have to be approximately 5,714 square meters. A linear bin four foot wide would need to be just under a mile long. Such an operation would also require a very large investment of startup capital and income stream in maintaining operations.
I am somewhat skeptical regarding this comment based on our own first hand experience in working with BSF using current BSF farming technologies. Assuming the claim has been vetted, would you are Dr. Tomberlin be more specific regarding the name of the company, the source of waste (food scrap, pig manure, mixed manure and food scrap ???), and additionally comment on what the company is doing with the larvae it is producing given the large quantity produced, and when and how long the company has been able to sustain this level of production? I think other readers would likewise be interested in a follow-up in this regard.
Terrence Green, Ph.D.
President, DipTerra LLC
Harvey, as a follow-up to my question regarding vetting Dr. Tomberlin’s statement that China is way ahead of the rest of the world in BSF technology, and specifically his comment that a Chinese company is producing 20 tons of BSF larvae per week grown off of waste, Dr. Tomberlin has since communicated to me privately that he is not at liberty to disclose any factual evidence supporting his statement citing a nondisclosure agreement he signed with the company.
While it is heartening to see more attention focusing on the potential use of insects, including BSF, in efficiently recycling waste in more environmentally sound ways, it is likewise important to demand more transparency and due diligence in vetting claims of accomplishment in this field. Scaling up BSF production to levels sufficient to make a significant impact in altering how we currently recycle waste streams is going to take a lot of effort, trial and error. It will require a lot more critical self-assessment of what is and is not working sans hype than has occurred in the past in this field.
The standards for vetting success should be the same as in any scientific and business endeavor. In science this means open transparency – proof through the exchange of data and information subject to independent review and validation. In business, operations that through the course of time prove practical and sustainable and which provide a viable means of sustaining the business.
In vetting the claims of a company claiming to have successfully developed technology for scaled up BSF larval production, here are at the very least three questions worth asking for those interested in assessing the accuracy of the claim:
Is there objective evidence that the company is using and has been using (not theoretically might or potentially could use) the claimed technology in achieving the scale of production it claims over a period of at the very least two years or more? (Note – its is important to differentiate between seasonal high and low yields over the long haul).
Has the company addressed effective safe and environmentally sound dissemination of all byproducts in recycling its waste and end products without evidence of any negative outcomes including acceptance of the operation at the site where it is located by neighbors and other interested stakeholders?
Is the company realizing an income stream from its activities including sales of harvested BSF and byproducts sufficient to offset its operating costs and the capital outlay required in putting it into operation?
Unless the answer is in the affirmative for each of these questions, claims made asserting a company is way ahead of the rest of the world, or that it even has a better way of farming BSF grown off of waste, must be viewed as premature and still unproven.
For those interested in seeing advancements in BSF technology as a sustainable method of recycling waste, and realizing the benefits that might one day accrue as a result of successfully working out the challenges still present in this field, a good starting point would be to insist on using objective criteria in evaluating progress in the field. This includes adhering the same standards ascribed to in science and business in evaluating progress, insisting that those who claim advances offer data that can be objectively reviewed and validated. Given the absence of any supporting documentation accompanying Dr. Tomberlin’s quote, I view the statement as yet unproven and premature.
Terrence Green, Ph.D.
President, DipTerra LLC
Terrence, agriprotein has been recycling food waste at a commercial level for some time now in South Africa. Agriprotein.com
Chris, I am familiar with Agriprotein’s operation. Recycling food waste, even harvesting larvae of the common housefly growing off of food waste, is not at all the same as growing BSF off of food waste. I am aware that Agriprotein claims they are farming BSF commercially. So far viewed from a technical and business perspective I have not seen evidence which would support the claim. Do you have accurate first hand data on their annual BSF production levels? Do you have independent verifiable information on their annual sales of BSF product? To what degree is their harvested product that of common fly larvae growing off of the waste? Many companies have for years been recycling food waste. In reality there is so far little objective evidence supporting the assertion that Agriprotein is truly farming BSF economically on a commercial scale.
Protix biosystems bv is active on the market in Europe (netherlands). Don’t know their break even point, but they use BSFL to make fishmeal and also have a partner (coppens diervoeding), good for a contract of 200 ton of insectfat and 300 ton of insect protein in 2015, as stated in an older(!) interview. Here’s another excerpt of this dutch interview I’ve translated for you, Terrence. I really appreciate the knowledge and vision (about compost and insect fuels, etc…) you put on your site. You probably know the company already, but hope it still helps in a way. Even if it’s just for supporting your contribution to a better understanding and economically viable implementation of the way nature works and likes things to be done.
“Protix chose the black soldiers fly partly because it can not eat in the mature stage of flight. The larva is therefore rich in valuable nutrients: proteins, energy and other micronutrients
required for pupation, the process where in the larva transforms into a full Wash fly, and afterwards the mating. The nutrients must be built up in the larval stage. Tarique Arsiwalla (protix): “The living
larvae then have to become a product. A good processing
and drying process at low temperature, on the basis
of air-drying ensures that the protein is preserved intact.
Separating the insect protein and insect fat is a different process than that of fish meal. ”
Protix now works with a patented process and delivers the fat off as a high 99.9 percent fat. Protix separates the insect skins
and makes three types of protein:
of the whole insect, only from the skin and a third of
the insect ‘fillings’.
The residual production of the larvae is organic material. “We supply this as an organic fertiliser and soil conditioner. So there is nothing left over. Via a heat exchanger we use the warmth of the growing larvae for the breeding of flies. ”
Hendrik Regal (coppens animal foods): “The products are now
presented in a form where we can process them and meet requirements of Trust Feed and GMP +. In the factory insect fats
can be processed as any other fat. ”
Insect Protein is currently still set equal to animal protein that is not permitted in animal feed. It is expected that this will get permission though, as for fishmeal.
In mid-2015 Coppens Diervoeding starts
processing insect fat . Insect Protein follows as soon as the law allows it ”
here’s the full article in dutch : http://www.agricontent.nl/assets/files/Pluimveehouderij/VLEESplv/plu011_vakvlees2Insecten.pdf
Who is the representative that you spoke with regarding the GRAS opinion of the FDA? Thanks.
I am so fascinated by your write up and was just wondering where I can get a very good training to learn how to establish the black soldier larvae as a commercial venture in Africa.
I will be very grateful for your help in this regards.