[ETA: Since creating this thread I have had second thoughts about bringing soldier flies to this property. I have put some of the following statements in red, to indicate that these claims may not be true (or no longer true). I was awaiting some answers from ProtoCulture, but their forum has become unavailable. For updates on this situation, or to read what I have learned since this time, see the soldier grub article in Lumeniki or read this thread starting here or the Black Soldier Fly Challenge thread.]
I'm planning to build a wire/wood bin for soldier grubs, and attach it to the bottom of a coop.*If* I can get a soldier grub colony established, there are numerous beneficial functions of this system. I listed many of these below. (All the quotes are from this excellent fact-packed resource Black Soldier Fly Prepupae - A Compelling Alternative to Fish Meal and Fish Oil ):
*Protect the grubs so they hatch into soldier flies and hopefully return to lay eggs: An expert does not recommend feeding grubs to poultry if they were raised in poultry manure although I have not be able to find a disease poultry can get from this in particular. Soldier flies are difficult to breed in captivity, so the only way you can get more soldier grub eggs, is from wild/released soldier flies. This is the only disadvantage of soldier flies, but it can mean they are impossible/expensive to replace and all the effort and money is spent only to learn this. If I do get enough soldier fly eggs I can use a different grub/worm bin (biopod), to raise grubs that are safe to feed poultry. I can feed these grubs/redworms humanure or things that the chickens don't like all that much like brussel sprouts or citrus, but I don't have a lot of scraps that poultry won't eat.
*Reduce flesh flies: "94-100% house fly control through larval competition and by repelling ovipositing house flies" Flesh flies carry numerous pathogens to humans and poultry (see diseases carried by houseflies, diseases carried by blowflies). Chickens can get a parasitic worm from houseflies, but other edible birds cannot.
*Reduce odor: "noxious odors produced by decomposing manure were reduced or eliminated by Hermetia larval digestion...[t]he chemicals which were affected include the methylester of heptanoic acid, acetic acid, 2-furnaocarboxaldehyde, propanoic acid, butanoic acid, isovaleric acid, valeric acid, caproic acid and p-cresol. These were greatly reduced or eliminated by larval activity within 24 hours."
*Remove nutrients from manure and spilled food, so that rodents (and flesh flies) are less attracted to the area: "Hermetia larval digestion of swine manure reduced nutrients as follows: N-71%, P-52%, K-52%, Al, B, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Mo, Na, Ni, Pb, S., and Zn were reduced 38 to 93%" A neighbor told me that alot of people he knew raised chickens and they always had rats.
*Reduce the pathogens that BSFL are known to reduce: "Hermetia larval activity significantly reduced E. coli 0157:H7 and Salmonella enterica in hen manure"
*Other pathogens are said to be destroyed in heat and apparently BSFL can survive in these temperatures and may contribute to higher temps. [Actually, soldier grubs seem to have about the same heat tolerance as these roundworm eggs, but they are rumored to crawl away from temperatures around 100 degrees Fahrenheit.] Roundworm eggs are the most difficult pathogen to kill by regular composting. Roundworm eggs are killed in a day at over 50 degrees Celsius (122 F) or a week at 45 degrees C (113 F) (source: The Humanure Handbook), but I think that is with composting using microorganisms, so I'm not sure if it is the heat that kills the parasite eggs (that doesn't seem extremely hot), or if the killing is done by the microorganisms that thrive in that heat.
*Reduce the need to clean out the bin by releasing liquid into a drainage area full of high-carbon sorbents like buried wood, twigs, and leaves: "BSF reduce manure accumulations 42-56%...The digested residue is a friable compost-like material with about 24% less nitrogen (net loss of 60%)." The type of manure is not mentioned, but most say poultry manure releases a lot of moisture.
I describe the bin and ask for suggestions in the BioPod forum.
Edited by Lumenos - 6/12/10 at 1:33pm