Black Soldier Fly larvae (BSF) are the juvenile grub of the BSF, and fish and chickens find them DELICIOUS. While the notion of cultivating fly larva (uh, don’t you mean maggots?) seems pretty nuts, ends up BSF are very different than your ordinary housefly. First, they don’t carry diseases, they cannot bite or sting, and, the experts claim, they won’t annoy you at picnics. They are voracious eaters of compost scraps (including pet waste), eliminating most food scraps in 24 – 36 hours.
Some very fun guys at a company called ProtaCulture have developed a product that has been specifically designed to attract, grow and harvest BSF and their yummy young. It is called the BioPod Plus, was over 8 years in development on 3 different continents, and can process up to 5 pounds of kitchen waste and pet feces a day! Here is a video clip of our friend Murray Hallam from his Aquaponics Made Easy video describing how he uses the BioPod to grow food for his fish.
Last fall when I was starting to think through a product line for The Aquaponic Source, I had a fascinating email exchange with Karl, one of the founders at ProtaCulture. At one point I asked him about the difference between using red worms for composting and BSF larva. After assuring me that he has nothing personally against red worms, here was his response:
- Red wigglers are not efficient for processing meats, dairy products, oily foods or grains. Black soldier fly larvae readily consume all of these food types. Worms also don’t process citrus, and large food needs to be chopped. BSFL do process citrus and chopping isn’t necessary.
- With worms it’s recommended that you bury the food scraps to avoid odor and pest problems. With BSFL the scraps can be put on top of the pile because they don’t last long enough to spoil and smell bad. BSFL give off an info-chemical that repels other flies and it’s relatively rare to see another species in the container.
- Worms require periodic harvesting because their castings are toxic to them, and this has to be done manually. BSFL will self harvest when they are mature. In their last stage as larvae their mouth is replaced by an appendage that helps them crawl out of the container. They empty their gut and excrete an antibiotic in preparation for pupation. The container has been designed so that the prepupal larvae drop into a bucket when they exit the container, and they can live in the collection bucket for several days, maybe even weeks before being collected. At this stage they don’t eat. From here, it is a simple matter to collect them and feed them to your fish.
- Worms require a fairly specific environment with regards to moisture, ph, and temperature. Different sources recommend keeping worms at a minimum of 54 and up to 70-84 degrees depending on the source of the information. BSFL are much more tolerant. Once a BSFL was tested by being submerged in isopropyl alcohol for two hours and it survived. They can survive between just above freezing and about 100 degrees.
- Worms process about three times their weight in food scraps per week. I assume five pounds of worms would be a substantial quantity and would consume 15 pounds of food per week. A BSFL colony in a 2 foot diameter container can process 11 pounds of food every day. Even with 10 pounds of worms you would still be limited to 30 pounds of scraps per week.
- Most kitchen scraps are converted into BSFL at a rate of 5 to 1 so 10 pounds of food scraps would yield about 2 pounds of larvae, i.e. delicious fish food, per day.
Sure convinced me, but tragically we don’t have BSF in Colorado! Ends up you need to be in zones 7 – 10 (sometimes 6) to have BSF, and because they are winged creatures having a native supply is a requirement. So there is a plus for the redworms – they won’t fly off on you!
For more information please check out The BioPod Plus at The Aquaponic Source.