The modern garbage can. That's the larvae of a black soldier fly. And scientist Jana Vašíčková was so fascinated by them that she began to study them. She's always been interested in biology, toxicology, and sustainability. During her doctoral studies at the research centre RECETOX, the larvae of the black soldier fly accidentally got in the way of her scientific journey. At the time, she had no idea that she would begin to study them in detail. What made the young scientist fall in love with the larvae? And are larvae of a black soldier fly the ideal path to sustainability? Read an interview with a RECETOX graduate about an unusual scientific topic.
What brought you to science? And what were your beginnings?
I've always enjoyed nature and observing what was going on around me. And it led me to study Applied Biology and Ecology at the University of Ostrava. I really enjoyed my studies; they were designed to turn students into government environmental officers. And I must admit; it wasn't enough for me. During my undergraduate studies, I got a "touch" of working in a laboratory and became fascinated with toxicology. I started thinking about what to do next and looking for a Ph.D. focusing on chemicals and their environmental impact. And I was lucky when I found Professor Jakub Hofmann at the RECETOX Research Centre, Faculty of Science, Masaryk University. And at RECETOX, I was accepted for my Ph.D. studies, so my real "scientific" career began.
Did you move from Ostrava to Brno for your doctoral studies?
Yes, it was like that. I come from the Ostrava region, near the ecologically beautiful location of the Cosmic Bird Meadows. They are alluvial meadows that have been revitalized over the last few years. I live in Brno now, but I like Ostrava very much. It can always be a pleasant surprise!
In your research, you are dealing with the larvae of a black soldier fly, Hermetia illucens. What was your path to such an unusual topic?
As part of my doctoral studies, I worked on soil ecotoxicology under the supervision of Professor Hofmann. I worked on projects investigating the effects of organic pollutants and pesticides on soil organisms, especially invertebrates. That's when I stumbled upon the larvae of a black soldier fly. And I was so intrigued by the black soldier flies that I became more interested in them. I'm a biologist by background, and I've always found animal behaviour fascinating. And black soldier flies can surprise. They're perfect machines that eat everything they can get their hands on. I started studying them, and I found out that in the world, diaphragms are already a term that is often used, especially about sustainable protein production.
So, what is so fascinating about larvae, and why is their use in practice synonymous with sustainability?
The larvae of black soldier fly can eat every crumb of our food scraps. Our waste is food for them; they are not picky and will eat all plant and animal waste. This way, we can quickly transform our scraps into a new food source. Moreover, their breeding is easy - it is not so much work. Just a practical and efficient invertebrate.
How do you take care of your larvae?
A colony of black soldier fly needs warmth, moisture, light, and food. The larvae have nothing to do but eat. I keep them in plastic boxes and feed them twice a week with leftovers from an Italian bakery around the corner from my house. They've been hiding my old baked goods themselves. My larvae aren't regular larvae - they're raised on premium Italian baked goods. Laugh.
And what if there's no pastry?
That's my backup plan B. My local brewery is hiding leftover brewer's grist, a secondary product of brewing beer. They have plenty of malts every day. And that's also part of my project that's gradually turning into a real business plan. My goal is sustainability in the form of using local sources of waste. The larvae completely dispose of the trash and become such protein "bombs" themselves and create a very high-quality fertilizer when they feast - success on all fronts.
You said that the larvae of black soldier flies become protein "bombs." What to do with them as a source of protein?
With the black soldier fly - as with humans - we are what we eat! If given a high-protein diet, they will contain a lot of protein. If they are fed a high-fat diet, they will be high-fat themselves. The fattened protein-rich bodies are dried, and ground and the protein-rich flour can then be used to make food for dogs, cats, fish, or chickens. Today, fish or soya meal is commonly added to animal feed, but these are not environmentally sustainable. For example, fishmeal is shipped to us halfway around the world. In contrast, we can produce such protein from the brood very quickly, the larvae are fattened in two weeks, and we use local sources.
What happens to the larvae when they grow up?
The first stage is the larva, it just feeds and feeds, and then it turns into a fly. The transformation is so energy intensive that the larva eats 24/7 to have enough energy. The fly mates lay eggs, and the eggs hatchback into larvae, which goes on and on. The other significant advantage of the larvae is that they produce fertilizer as they eat. And that can be used in a plant pot. My neighbours come over to my place for fertilizer. Laugh.
So, do we have a larva that disposes of all the waste, becomes protein-rich, and produces fertilizer?
Yes, that's right, their excrement can be used as fertilizer.
What are your following plans for the black soldier fly larvae?
My goal is to build a farm where the larvae of black soldier flies is fed on leftovers from local food production. We will then use the larvae to produce dog food, and the following product of the farm will be fertilizer. However, within the European Union, the larva of a black soldier fly is classed as a farm animal, and it is therefore forbidden to feed it waste. However, it is often a nutritionally valuable raw material. A typical example of this is waste from canteens or restaurants, which is nowadays most often processed in biogas plants. For the time being, we are feeding the larvae with secondary raw materials from food production, but legislation will also change in time.
What would such an ideal farm look like?
Even though we don't have such farms here yet, we can find them abroad. In the Netherlands or Poland, farms feed the gophers with bio-waste and then sell the larvae as a source of protein in feed for farm animals or pets. Farms are real farms in the true sense of the word. Trucks bring in various organic residues, and the larvae eat them. The harvested larvae are dried, and the fat is separated and ground. In the form of flour, they are added to the feed. Granules or even canned dog food are already available on the market, and the larvae become part of our pets' diet.
So, did black soldier flies become a scientific love at first sight?
Laugh. Not at first sight because of their appearance, but I found them instantly fascinating because of their unique abilities. The larvae of the black soldier flies connect my passion for nature, biology, and sustainability. I see huge potential in them, a sense of purpose in their breeding, and a way to produce a sustainable protein source locally. I never thought my scientific topic could become a business venture. Although we already know a lot about larvae, I am fascinated to discover their other uses. I'm always learning and improving. Raising black soldier flies’ larvae is a science.
So, the larvae… are they a current topic, right?
They certainly are! Organisms that dispose of all organic waste, and yet we're reaping unprecedented benefits.
Dr. Vašíčková, thank you for the interview. And we wish you every success in your research and business.
Scientist Luděk Sehnal, a successful applicant for several prestigious scholarships for which he and his family traveled the world, is finishing his work in Germany and plans to return to RECETOX. He wishes to pass on his experience and support the development of excellent science in the Czech Republic.
Although many people imagined Aneta Vrzalová as a medical student, she preferred to study Environment and Health at the RECETOX research center, Faculty of Science, MUNI. And she has never regretted her decision.
