Tuesday, September 25, 2007

Beneficial Byproducts of BSF Rearing

During the warmer months or in climate controlled conditions, for every 100 kgs of food waste added to a BSF bioconversion system approximately 20 kgs of live pupae or 'grubs' are produced. Depending on the moisture content of the food scraps and the ambient humidity of the system, several liters of 'tea' are also produced as liquid effluent. After filtering through cheese cloth and dilution at a 10:1 or 15:1 ratio, this tea may be used as a liquid fertilizer or foliar spray. This effluent is also an extremely powerful attractant for adult BSF females, and will result in the ovipositing of eggs on any surface near the collection receptacle. With this in mind, tea from BSF systems may be used to start up additional units, by enticing gravid females to seed new piles of scraps. For every 100 lbs of scraps, roughly 5 lbs of a black, friable residue remain at the bottom of any BSF bioconversion system. This casting residue, along with undigested food remains and shredded chitin exoskeletons from BSF larvae, creates a mixture that is undergoes further decomposition by beneficial bacteria and fungi. This combo material may be used directly in the garden as a nutritious soil amendment, or fed to redworms for transformation into vermiculture castings.

10 comments:

tomm said...

I just ran across this blog and would be happy to correspond about BSF. I have raised them in Iowa, Washington, New Mexico and Texas where I reside now. At the moment I have about 20 adults flying around in a greenhouse. I hope I have things set up so that they will mate, lay eggs, and hatch into larvae that consume chicken manure.

Sarah said...

Tomm or others - what do you think about using BSF larvae to consume chicken waste, and feeding BSF larvae to the chickens? The close-loop approach really appeals to me, but I can understand how it might be risky to feed chickens with larvae that consumes their waste. I'm also considering buying the BioPod and wonder if people have had luck with it.

Thanks!
Sarah

Maxwell said...

My question is that once you've got a BSF population rolling (I inadvertently did so, and I'm intrigued to keep it going) how do I separate the compost from the larvae to use in my garden? I don't want to introduce larvae that would eat my vegetables next year into my soil, even if they area GREAT at composting.

Adam said...

hey, I have been involved with bsf discussion quite a bit now and don't know how long it takes them to pupate. (once still and dormant, how long until an adult bsf emerges?)

Greenie said...

between 2 weeks and several months, depending on a multitude of factors - mostly environmental. Cool, dry weather keeps them dormant.

Unknown said...

I'm a newbie at this and set up my composter about 3 weeks ago. Today I went out and my biopod bucket had about a pound of larvae big and small. It was around 90+ today and will be 100+ tomorrow. Does the fact that there was a mix of large and small larvae mean that the pod overheated? When I looked inside I noticed that their was still hundreds if not thousands eating away.

--Drew

famayes said...

I have been raising BSF for a few years just by accident in my compost pile. I started a homemade BSF pod with the idea that I would get chickens one day (but havent so far). A friend just asked to buy BSf from me. I have no idea what to charge or them. I know on-line they sell for about 10$ a cup, but that seems too much to sell to a friend for chickens. what do you suggest as a price?

Anonymous said...

Let's revive an old thread shall we? :)
I have a bunch of BSF prepupae, is there a way I can have them go dormant for 4-5 months then let the flies emerge when the weather starts to warm up outside?

Greenie said...

@ Drew - when you get mixed ages in your crawl-off bucket, it is usually attributed to very high temperatures. Keep the unit in full shade, crack the lid open and if you still get a lot of light colored grubs crawling off, simply dump them back in so that can continue feeding. A few folks have recommended ice cubes in a zip lock on extremely hot days, but we have not tried that yet at our research facility.

Greenie said...

RE: Dormancy Post: BSF do this naturally in the Mid-Atlantic region, so try to simulate the conditions where they would naturally over winter. Keep them slightly moist, covered with some compost or leaf mulch and safe from predation (hungry animals will search for anything to eat over the winter months and you don't want them finding your stash). Don't use a deep bucket - the shallower the better due to carbon dioxide buildup (CO2 is heavier than air and can suffocate the prepupae in tall containers). Chicken coop wire is great for added security!