Adventures in Composting... with Maggots!

[webmaster]

Fascinating article about a gardener's experience [url=https://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/07/26/HOEIV3JNR.DTL&type=printable]creating compost with maggots[/url]. They throw in animal feces, chicken leftovers, moldy mozzarella and it's eaten in an hour or so, and all bad bacteria is neutalized, resulting in a compost ready for your garden.

Maggot composting can work well if your household generates lots of food waste, if you raise chickens or if your yard is too small for a standard composting bin. Larvae can also be useful if you have lots of pet feces - including from dogs, cats, pigs and chickens - to dispose of...

100 pounds of food scraps will produce 5 pounds of soil amendment and 20 pounds of well-fattened larvae...

The downside is if your composting material consists of yard trimmings or if you need a lot of soil ammendment.

But here's a cool part about maggot composting. A large-scale conversion plant can significantly reduce methane production, a greenhouse gas. It can be used by restaurants and other industries with a lot of scraps and feces to create soil ammendment or even biodiesel fuel.

If they divert their food waste, any fair-size city could set up a bioconversion plant turning food scraps into renewable fuel.

There are a few caveats about maggot compost, like needing a hot climate, however this article is a fascinating read and may be useful or inspirational.

[cynthia_h]

I read this in the San Francisco Chronicle yesterday morning. Unfortunately for me, I *started* reading it while still eating breakfast.

I stopped reading and found another article to read while eating.

THEN I finished the "maggot" article. These "maggots" are actually ravenous Black Soldier Fly (BSF) larvae.

I'm not sure how (or whether...) to attract them to my compost. Talk about mixed emotions...but then again, they clearly do the job--quickly and completely!

Cynthia H.
USDA Zone 9, Sunset Zone 17

[petalfuzz]

But what do they do with the larvae after the scraps are broken down? Ugh...

[cynthia_h]

If you "fast forward" through the article, the last section describes the various potential fates of these BSF larvae ("maggots").

Cynthia

[applestar]

It's going to take me a while to *digest* this idea.

But seriously, it's intriguing as a "waste disposal system" but it sounds like the BSF larvae eats EVERYTHING UP? Not leaving much for us gardeners to amend our soils? Will there be some sort of "BSF manure" and how do you separate out the larvae (Oh! I think I'm avoiding the "m" word )?

BTW, I tried describing the maggot-infested moldy mozzarella to my DH and and he overrode me in a LOUDLY ESCALATING voice -- "I DON'T WANT TO HEAR ABOUT ANY MAGGOTS IN THE COMPOST! DON'T EVEN THINK ABOUT IT!"

[cynthia_h]

See the excerpt quoted by our webmaster: "100 pounds of food scraps will produce 5 pounds of soil amendment and 20 pounds of well-fattened larvae..."

The BSF larvae will die when temperatures drop, so it's NOT a perpetual system. It's only for warm weather. (Thank goodness...)

Or you can use the larvae as the author recommends in her article. No, I'm not gonna give *that info* away. You can read the article, just like "webbie" and I did the other day. It starts off rather revoltingly, but becomes pretty scientific and much less revolting as you go along.

I was just unhappy to have discovered the article while I was still eating breakfast.

Cynthia

[applestar]

I just had an idea
I wonder if these guys would be a good alternative for pet poo digester? I read somewhere that the dog poo digester doesn't work for cat poo because cat poo is different from dog poo -- too much protein? I don't want to put it in the trash to add to the landfills though. Right now, I'm using flushable corn-based cat litter and flush everything, but this way, it's one less waste for the local water treatment plant to process.

[JennyC]

Black soldier fly larvae turn into black soldier flies, right? At least some of them? Then how do the flies interact with the local ecosystem?

OTOH, this might dovetail nicely with our discussion in another thread about composting toilets... [url]https://www.helpfulgardener.com/forum/viewtopic.php?t=9623[/url]

[applestar]

Black soldier fly larvae turn into black soldier flies, right? At least some of them? Then how do the flies interact with the local ecosystem?

Very good point! According to this link https://www.thebiopod.com/pages/pages/bsf.html (same one mentioned in the article), it looks like you're OK with the native status for sure. I think I've seen these guys around here as well, although I might be thinking of the wasp it mimics. I wonder if this means that once the warm weather rolls around, the flies and maggots will come back without having to replenish the supply... I.e. what can the cold-winter folks do to roll over the supply (keep them as pupae somehow?)

OTOH, this might dovetail nicely with our discussion in another thread about composting toilets... [url]https://www.helpfulgardener.com/forum/viewtopic.php?t=9623[/url]

"Great minds..." I was thinking the same thing....

[ckinney]

I have had these maggots since I first started a compost pile, they just kinds showed up. Nice part is I only rarely see the flies, the are large and sleek looking. They compost like crazy, only problem is that I get maggot carcasses in my compost, doesn't seem to affect the plants at all.

They also help three year old son get into the habit of composting, he likes to see the "yukky bugs."

When I first got them they kind of freaked me out, but now they are just part of the system, found I can put all kinds of items in there, including old cotton t-shirts and such and they are gone within weeks.

[LazyGirl]

I decided to experiment with my pile when I saw these guys. I started adding all sorts of taboo leftovers: sausage, pasta, salsa... the works. These guys are serious consumers! I know this is gonna get a laugh - they ate a WHOLE sausage in 24 hrs!!! (I am a scientist by profession so I bury things and check back later to see how quickly they get eaten)

I would like to see if anyone else is as experimental as I am or if I am missing any glaring compost no-nos?

I do have the "normal" things in there too like grass clippings, shredded paper, etc.

[american_gardener]

Interesting article Webmaster..

The Title of this thread was a bit confusing though.. composting isn't the same as feeding maggots. In a compost pile you wouldn't have any maggots at all.

But, now after reading the article I can see that it wasn't about composting at all it was about disposing non-compostable items by feeding em to the black soldier fly larvae.. and then using the feces from the maggots as a soil amendment.

So, I guess it would be a good alternative for those who like raising things.

I just had an idea
I wonder if these guys would be a good alternative for pet poo digester? I read somewhere that the dog poo digester doesn't work for cat poo because cat poo is different from dog poo -- too much protein? I don't want to put it in the trash to add to the landfills though. Right now, I'm using flushable corn-based cat litter and flush everything, but this way, it's one less waste for the local water treatment plant to process.

I know a person who raises the BSF maggots aka phoenix worms to be used to feed animals such as birds, chickens, frogs, turtles, fish(bait) and probably many others. According to info I got from him.. they can digest any kind of poo. And the fly does not spread disease like the dreaded house fly because they only live a few days to breed and then die. They have no workable mouthparts.

Dave

[LazyGirl]

Dave -

That makes sense. After thinking about it and reading up some more on the BSF, they are 90% bio-efficient which means that if I wanted to use them to compost food and yardwaste into usable organic matter - I would have to somehow recycle the pupae... and I'm not interested in that. Also, if the pile is really getting hot enough then these guys shouldn't be hanging around in such high numbers.

I'm not sure if its the time of year, or the fact that I stopped emptying my fridge into the compost pile, or that I got rid of the excess moisture by watering it less (yes, it was real hot out and I watered it like a fruit tree), or that I started turning it weekly... but there seems to be less of them.

It also doesn't smell sulfurous anymore which (I think) is a good thing and there are definitely fewer buggers in there. I'm kind of glad cuz for a while there it looked like the city dump had moved into the backyard.

[David Taylor]

Guys, this is the wrong critter to be courting for composting. RED WORMS. Vermiculture. I'm experimenting with it right now. I've got a 4 ft x 8 ft. worm bin. I had a die-off and have to buy some more of the wrigglers, but in the past I've found myself with hundreds of pounds of worm castings, that's the name for their poo, and worm castings is arguably the best organic fertilizer there is. I've ended up with hundreds of pounds of worms as well. What do you do with all those worms, especially when its a heck of a job to separate them from the bedding? I'm going to see if I can't let the chickens sort them out for me, and cut back on that feed expense.

[LazyGirl]

David,

I noticed that you are in Crest California which looks to be desert-type area. I had a previous post about worm temperatures and was wondering how hot it gets for you and how your worms do in the heat.

Thanks,
Tania

[David Taylor]

LazyGirl,

Crest and San Diego County west of the Laguna Mountains averages somewhere between twenty and thirteen inches of rain a year, so technically little Crest here is not desert, speaking as a hard-core Desert Rat, who only wishes he could live in Wikieup, Arizona. Temperature-wise, we shoot way past a hundred degrees, Fahrenheit, and worms are supposed to do their best between 60 and 80 degrees. My original worm bins were inside an old barn, where the temp could easily be kept in comfortable range. They'd still be there if the roof over the bins had not collapsed and ruined them.

What I ended up doing was building a free-standing bin, about waist-high on legs, four foot-by eight, the outside walls one foot tall, with a canted roof of plywood, tar paper and sheet rock. Center-line, eight foot length, is roughly two feet tall. Both sides of the roof and the eight-foot long walls are hinged. Down the center is chicken wire that divides the bin into two sides. With the first bins, I found that four feet deep is just too hard to work a shovel into. Two feet is manageable, also working toward my plan to see if I can supply my chickens with a supplemental food source of protein, but that's way off.

I placed the bin under what I thought would be enough shade, but as it turned out, the sun still spends way too much time beating down on it. Best laid plans, right? Now I'm thinking I have to build a shade source over it. Unlike the desert, the air does cool off at night, generally, during the summer, so with enough insulation, the temps should be stable inside the bin itself. The design offers some insulation, but I'm going to have to do more. I'm even kicking around trying to build a straw bale structure around it, that could also serve as a root cellar, if I do it well. Heat, I think, contributed to my recent die-off, but I think the zinger was the horse manure I used. Despite some efforts to reduce the issue, I'm afraid the wormer the horse owners uses comes out intact enough in the manure to kill earthworms. Since then, I've made a point to compost the manure. Even if I don't have enough brown material and lose some nitrogen, its better than killing off the worms in the garden.

The reason I put the bin on legs is, I can paint the legs with something like used motor oil, and ants and bugs can't get in. I've also ended up running my chicken run's electric fence system around the legs to keep out mice, rats and squirrels.

I'll keep you up-dated, as this is a work in progress.

[astevn816]

Guys, this is the wrong critter to be courting for composting. RED WORMS. Vermiculture. I'm experimenting with it right now. I've got a 4 ft x 8 ft. worm bin. I had a die-off and have to buy some more of the wrigglers, but in the past I've found myself with hundreds of pounds of worm castings, that's the name for their poo, and worm castings is arguably the best organic fertilizer there is. I've ended up with hundreds of pounds of worms as well. What do you do with all those worms, especially when its a heck of a job to separate them from the bedding? I'm going to see if I can't let the chickens sort them out for me, and cut back on that feed expense.

If you happen to know anybody who is into fishing they would love to have to have as many worms as you want to get rid of

[rolivier79]

One of the neat concepts about using the soldier grubs is that you can convert most of your food waste to grubs that you can make available to attract song birds back to your yard. I use a birdfeeder that I got from wild birds unlimited that doesn't allow for the feeding of pigeons... and now I support our local song bird population with 1 - 2 pounds of grubs a day... I guess it's similar to going to the park and feeding the ducks with your leftover bread.

[sweet thunder]

So how long do the larvae live?
If you're feeding them to chickens that means you're interrupting the breeding cycle, right? So do you just keep buying new generations of larvae, or am I missing something?

[rolivier79]

Since one adult female can easily lay 1000-2000 eggs, you don't have to purchase anything. I estimate that I have about 10,000 active in my grub composter right now and when they are ready to pupate they crawl out of the unit into a collection bucket...

At this point I collect up to a pound of fresh grubs a day. I don't have any chickens or aquaponic fish so I feed them to the local song bird population in a bird feeder. Sometimes I take a few extra's and throw them under a nearby bush so they can mature into adults and mate.

The typical adult fly is quite unique, because the adults themselves do not and can not feed on waste. All they do in the 8 days that they are allive is sit under the leaves of a tree waiting to lay their eggs in my BioPod. They are not associated with the spread of disease. All adults lack a digestive system and therefore the larval stage has a high accumulation of fats and proteins.

Like worms they thrive on Aerobic decomposition and they grind, aerate, and excrete digestive enzymes. In large enough numbers they will devour anything (80-90%) you throw in your composter in less then 24 hours. In reality they mostly eat the aerobic bacteria that live on fresh waste. They also digest a few easily accessible nutrients. But unlike earth worms their digestive track is limited and they are not the most suited for making the final compost product. As the Grubs are specialist in recycling nutrients quickly, Earth worms are still better at making enhancing soils and making compost. However, they do provide for a great backyard source of protein that can be harvested on a daily basis. They do not smell.

Most people try to eradicate them from their compost or worm bins... All I am doing is facilitating man to work in a more productive way with Nature versus the other way around. All of my grubs are clean and perfectly nutritious and 100% sustainable.

Some great independent sources are:
[url]https://www.youtube.com/watch?v=BnfkW4WgtG8[/url]
[url]https://en.wikipedia.org/wiki/Black_soldier_fly[/url]
[url]https://blacksoldierflyblog.com[/url]

[rot]

... 
In the rainy season I'll find the black soldier fly grubs marching across the deck radiating from the bin. We've had dry winters and more birds so I'm not seeing so many these days.

Never seem to be a problem around here. Not a lot of the flies and the compost gets digested.

Somebody up in Washington is experimenting with black soldier fly larvae to digest cow manure and then use the grubs to feed farm raised fish.

Now the maggot bucket seems a little bit much for me. That's where a bucket has some holes in the side not far above the bottom. The bucket is suspended from a tree with road kill or something in it. As the maggots multiply, they fall out of the holes and the chickens feast on them. I've also heard of hanging the bucket over a pond for fish.

I guess it all depends on how far you want to take things. All part of the cycle.
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