Experiment causes black soldier fly larvae colony to crash!

Okay, maybe the blimp image is a little extreme, but it’s difficult to get attention on the internet these days. 😛 The good news is that bringing my BSF colony (Hermetia illucens) back into balance shouldn’t be all that difficult. In the past when I’ve run into problems I’ve corrected them by lessening the amount of food scraps that I introduced into the unit, and that is what I’m doing currently.

BSF larvae can eat almost anything

BSF grubs will consume almost anything organic except high cellulose materials like woody stems and grasses. They will quickly eat just about anything that has available calories including food waste that would probably be toxic to humans, like decomposing fish for example. The fact that they are able to efficiently digest such a wide range of material is what makes BSF larvae such a powerful tool for processing waste.

About those decomposing fish…

I help my neighbor manage the small pond behind his house. Recently several of his fish died and I did him the favor of removing them a few days after they floated to the surface. The fish weighed about 5 pounds (2.3 Kg) total and by the time I removed them they were already very stinky. Instead of disposing of them like a normal person I decided to see how quickly my BSF would process them. I’m happy to report that my small colony completely consumed the fish within about 2 days. I am unhappy to report that after I added the decomposing fish to my BSF unit it began attracting blow flies and house flies.

Black soldier fly grubs produce an info-chemical that repels pest flies, but there are limits as this test illustrates. The odor of these decaying fish was a powerful attractant to undesirable flies and it overpowered the repellent properties that are normally very effective in a BioPod.

I’m currently using a homemade BSF unit (not any more!) because BioPods are not yet available. My homemade unit is a less efficient design and I’m sure that this made my recent problem worse than it would have been. My unit doesn’t deal with liquids as well as a BioPod so the problem was less contained than it would have been with the commercial product. I will be happy when the first BioPods arrive.

And now the good news

Even the extreme imbalance created by adding these decaying fish to my colony can be corrected with a little time and care. Of course I’m more cautious about sanitation while the pest flies are present, but in reality I don’t need to do much other than stop feeding the colony and let the other flies cycle through. It’s now been about 5 days since I added the fish and my colony is almost back to a balanced state again.

You can avoid this type of problem easily

My test with the decayed fish was something that most people would not have tried, but I’m involved in testing the limits of this technology. If you use BSF larvae to process your normal household food scraps it’s very unlikely that you’ll experience anything like the crash I just created. You can even add food that is somewhat spoiled and you shouldn’t have a problem like my recent experience.

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14 thoughts on “I crashed my pod

  • June 27, 2008 at 5:29 pm

    I love the Hindenburg photo. (big grin)

    So glad to hear that the colony can quickly rebalance itself. I know that I would have tossed the rotting fish in the bin too just to see what would happen.

    Now this makes me wonder if this would even have been an issue in a BioPod. Any idea when they will start shipping? I know when I called them they said they had just received their first shipment.

    I still wonder how one would harvest the larvae’s droppings without having to dump the whole bin. That will be my experiment when I get my colony going.

  • June 27, 2008 at 5:53 pm

    Thanks Barbara. I think I’ve run into some miscommunication with ProtaCulture about this first delivery. I correspond fairly often with Dr. Olivier who created the BioPod so I’m sure I can get it straightened out quickly.

    I’m also curious about the best way to separate the compost from the larvae. Let’s compare notes later on.

  • June 27, 2008 at 7:17 pm

    Hi Jerry,

    I am utterly amazed at the potential for waste management that these little guys hold. I was thinking about setting up a colony here in Chicago and was wondering if they would be present in my area. Thanks for this wonderful blog!

  • June 27, 2008 at 8:45 pm

    Well thank you Aaron, I’m really enjoying the blogging experience and I’m glad that you’ve discovered BSF. I’m very grateful to Dr. Olivier and Dr. Sheppard for their hard work researching and developing black soldier fly technology.

    One of the things I know least about BSF is their current range. I believe their native range is centered in the southeast, but I’ve read that they can be found on most of the continent. If you want to culture BSF it can always be accomplished by seeding the area where you wish to keep them.

  • July 4, 2008 at 2:35 pm

    I think the simple way is to have a unit expressly for raising BSFL. There would be other advantages besides easy collection, such as a way to “compost” meat, dairy, citrus, and almost anything organic except grasses.

    I don’t have a great design for a homemade BSF unit but you can use almost any covered container with an exit ramp. For a few reasons my focus is on promoting the BioPod by ESR/ProtaCulture. It was designed and tested by Dr. Paul Olivier, one of the leading authorities on BSF technology, and I doubt that most people could build a unit that will function as efficiently.

    Considering the effort that went into the BioPod I believe the price is very reasonable. (I recently bought a Rubbermaid garden cart for the same price as a BioPod.) Also ESR/ProtaCulture is a model company and deserves to prosper. I recommend taking a look at the ESR website, I think you will be impressed. :)

  • August 20, 2008 at 12:21 am

    question: I’m new to home worm composting. I have a Can o’ Worms that’s about 2 months along and seems to be doing well.

    Yesterday, I found ~lots~ of what I think are the pupa of the black soldier fly. At least, they look a lot like your photos. But, I don’t see any that wriggle around.

    I wonder how they got there?

    Can they just live out their life cycle in the worm bin? There is no opening in the Can o Worms for the adult soldier flies to get out.

    The BioPod seems like an amazing product. Now I wish I’d bought that instead of the Can o’ Worms.

  • August 20, 2008 at 7:15 pm

    Hi teel,

    I can only assume that the BSF were present in your worm bin for a few weeks and you just didn’t notice them. They would go where the food scraps were and I’m guessing they were buried.

    Normally the dark brown mature BSF larvae would crawl away from the food source to pupate. Since they couldn’t exit your bin they must have just pupated and in that stage they look pretty much the same, just stiff. It’s very unlikely that they will be able to mate in your worm bin after they emerge as adults.

    BioPods and BSF are great, but so are worms. Why not enjoy your worms until you have some extra money to spend on a BioPod. If you’re handy you could always build your own version of a BioPod like I did before they were available. My homemade unit isn’t nearly as efficient as my BioPod but I was still able to culture BSF with it.

  • August 21, 2008 at 12:02 pm

    Thanks for your moments and encouragement! Most, not all, of the pupa are rather light colored not dark, so I’m hoping these aren’t something else that’s undesireable. I’ll email a photo of the pupa.

  • August 21, 2008 at 3:13 pm

    The light colored stage of the BSF larvae are usually actively feeding. I believe they slow down for a short time just before they shed their skin when growing. I will sometimes see a few idle larvae among thousands of active ones so you have a bit of a puzzle there teel. Maybe the photo will help.

  • April 6, 2009 at 8:57 am

    Just a comment on price. Value does not always weigh out over affordability. I agree that for the money, the biopod is a good buy. Unfortunately I also agree that it is too extensive. I know that I could build a unit out of 5 gallon buckets, screen and pvp pipes that would accomplish the job. Granted, my units would probably be less efficient, but not to a greater degree than the price difference. If I spend 20 dollars making a pod, and it only works half as well as a biopod, then I could just build 2 units. Furthermore, if I am reading the page correctly, the pods are made in Vietnam. At 200 dollars a piece after shipping, why not make them here?

  • April 6, 2009 at 11:03 am

    When I started culturing BSF a few years ago there were no commercial units available. Dr. Olivier had generously posted images of his BioPod prototype so I made a crude imitation of it. As you say, it wasn’t as efficient or as convenient as a BioPod, but it did work. Also, since I live in an area rich with black soldier flies I had a big advantage. I’ve always encouraged people to build their own units and I’ve given advice about it on a few forums.

    The fact that BioPods are made in Vietnam is not a simple matter of outsourcing for cheap labor. Dr. Olivier has been working with the Vietnamese for several years and he lives there. He is trying to help the people improve their lives by using BSF as a sustainable and efficient way of feeding livestock and processing waste. I don’t know if BioPods could be made and distributed more cheaply here, but I believe the Vietnamese people stand to benefit from making them there and I support that. Furthermore, BioPods are distributed around the world so making them in the U.S. might make them cheaper here, but it would only serve to make them more expensive elsewhere.

  • September 29, 2009 at 11:46 pm

    Another great way to crash your pod is to give your colony a huge amount of food for awhile and then cut it off. The resulting population boom will consume all the food available without any of them getting enough to remain healthy, and the colony will eventually “crawl off” to a large degree. The remaining larvae will crawl around in a very sticky mess. Amazingly they can live without air for quite a while as they navigate deep in the brown goo.

    Adding to the carnage was the onset of somewhat cooler weather, but IMO the main issue was the near cut-off of food supply. The food I gave them during the 2 week period of gorging was a couple of large buckets of soggy, moldy biscuits. Yum. I fed them approximately 5-10 lbs a day for about a week and a half, as fast as they would eat because those biscuits were ripe! The BSFL proceeded to fill up a 2′ biopod to 1/2 way, at times the surface was 2-3″ deep with grubs. Unfortunately I didn’t have any large fish or chickens handy to feed them to.

    Keep up the good work!!

    • September 30, 2009 at 2:09 pm

      Hi Dave,

      I also think a steady supply of food is the best approach. I often add non-pressure treated sawdust to my BSF colony and I have a feeling that could have helped in your case. If the waste becomes wet it can lead to anaerobic conditions which are associated with the crashes. Of course you must have adequate drainage for a BSF colony but I doubt you could effectively drain certain waste such as the biscuit blob. :)

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