Wednesday, January 5, 2011

Black Soldier Fly Larvae

Photo from Wikimedia Commons

I hope the title of this post doesn't put anyone off.  If you're not fundamentally squeamish about insects, I promise there's nothing terribly icky about what I've got to say today.

Included in my formal list of goals for this year is the project of trying to feed our laying hens more and more with food we produce ourselves.  We've already got well established routines that provide some of the chickens' food, such as kitchen scraps, trimmings from the garden, feeding them Japanese beetles and squash bugs in the proper seasons, and gleaning acorns for them in the fall.  Still, we end up buying a few 80-pound bags of feed for them each year.  This is grown organically, fairly local to me, and milled by the farmer that grows it, so on that score I feel pretty good about it.  But it's a 45-minute drive to buy the feed, and the price (though much cheaper than the nasty pelletized chicken feed from Tractor Supply) has been nudging up steadily ever since I started buying it.  This feed easily accounts for more than half of the hens' caloric intake over the course of the year.

So I've been looking a bit harder at what we might do to close the gaps in our homestead economy and nutrient cycles.  Worms from our vermicompost are an excellent possibility, but I'm going to leave that project for another post.  Right now I'm going to talk about the Black Soldier Fly, which is probably the coolest idea easily adapted for use by very small scale homesteaders I've come across in a long time.  I have this tendency to think that if I've heard of some cool idea, then everyone else already has too.  But I've gotten comments from time to time that ask for more detail on stuff I mention in an off-hand way.  So I'm going to review what I know about this species and how those with small backyard poultry flocks can partner with it to their advantage.

The Black Soldier Fly is well established in many parts of the world, including most of North America in hardiness zone 7 or warmer.  Though it is a fly, it's a world apart from the common housefly in terms of the nuisance factor.  The adult phase of this insect's life, the only time it can fly, is very brief and devoted solely to reproduction.  The adult BSF doesn't even have a working mouth, so it cannot bite or eat and is not attracted by food, except as a resource for the next generation of BSF.  Even so, the mated female BSF does not land on food.  She seeks to lay her eggs nearby - not on - a food source, where the newly hatched larvae will be able to land on the food and begin feeding.  BSF larvae can consume small amounts of meat, but this is not a species that specializes in carrion.  Mostly what she's looking for is decomposing plant matter.  In fact, they may already be resident in your compost heap.  Once her eggs are laid, the adult fly has accomplished her mission in life, and dies shortly after.  The males also die shortly after mating.  The larvae remain on the food source as they pass through several sub-stages of growth, until they are ready to pupate, at which point they seek to burrow into the earth to complete their development into adults.  So you can see that there is little purpose or opportunity for the BSF to interact with humans in any way, unless we deliberately facilitate such an interaction.  Indeed, even if you live in a region with a BSF population, it's entirely feasible that you have never noticed these insects before, since they have little interest in us, and such short life spans in adult form.

The point at which we would want to intervene in the life cycle of this insect is when the larvae are fully grown and ready to pupate. Clever people have designed a clever contraption for harvesting the mature larvae at just this stage.  Or rather, using the BSF's instincts in order to have it harvest itself.  The BioPod is a custom built bucket system that provides an exit route for the larvae leading to a closed container, which makes feeding them to poultry or other livestock trivially easy.

I'm going to post another piece soon about the knockoff BSF composting buckets I'm working on.  What I want to dwell on a little more at this stage is the idea of partnering with this species.  Although in my formal goals for this year I wrote that I'm not committing to adding another species to our homestead, that was an oversight.  In reality, the Black Soldier Fly is another species I very much plan to work with.  It may not look like livestock, just as our red wriggler worms for the vermicompost bin didn't look like livestock.  Perhaps they're not.  But they will be a new species for us, and partnering with them will involve a learning curve.  I see the cultivation of these insects as one more item in the self-sufficiency toolbox; one more thing that reduces our dependence on fossil fuels.  For without fossil fuels it would be very difficult for the farmer to harvest the grains that make up our purchased feed, and very difficult for us to go and buy them multiple times per year.

It may seem grotesque to call my intended relationship with BSF a "partnership."  After all, it looks pretty exploitative from one perspective.  But in reality, I don't see this as ethically any different than keeping other species for food.  I will be establishing an insect where it doesn't currently exist, and responsible not only for feeding each generation, but also maintaining a "wild" population that survives to adulthood in order to reproduce and create the next generation.   After obtaining a starter colony, I'll need to heavily "seed" our garden soils with ready-to-pupate larvae.  This will reduce my usable harvest in the first year.  But with luck, a good population will take root right in the backyard, and continue to take advantage of the shelter and food the composting buckets will provide for them. From what I've read, I will very much need to actively tend the compost buckets.  I expect to derive both animal feed and a small amount of compost tea from this partnership.  In other words, the BSF will become part of the system of this homestead.  I'm always looking for ways to increase the diversity of species, and the connections between them, on our tiny piece of land.

Sooner or later I'll post more on the buckets themselves.  In the meantime, having read this post, would you humor me please, by participating in my poll on Black Soldier Fly composting?  It's on the sidebar of my blog.  I'm curious how many of you have heard of BSF cultivation before, and what your attitudes towards it might be.


Lynda said...

I've saved the Black Soldier Fly Blog on my Favorites and will start working on buckets in the coming weeks. Looking forward to comparing notes!

Arnica Snow Garden said...

You left out an option on your poll.

"I have heard of it before and would do it if I was in zone 7 or warmer".

Out here in zone 5... not an option I'm guessing.

Too bad. The worms could have used some company.

Anonymous said...

Please post more soon! I am always looking at more feasible (and nutritious) ways to feed my ens so this is of great interest. I live in a zone 5/6 so they not be able to live outside 'naturally'.
I'm with Arnica - my worms would love the company!

meemsnyc said...

This is such an awesome idea!!

Christopher. said...

Funny you should bring this idea up - I read about something similar used here in Aotearoa NZ by a couple up north who are self-sufficientishers...

see this post


Unknown said...

I voted option 1 but really they just showed up in my compost bin about 4 years ago. (I'm in central MD, zone 7). I didn't know what they were until I saw references to them on some other blogs I follow. This season I started modifying my technique to encourage them, mainly stopped turning the pile. Since I have no livestock, I'm not sure if they are really beneficial for me in terms of finished compost, but they sure work fast and the songbirds seemed to spend a lot more time hanging around the compost pile. It's also nice to be able to compost all kinds of waste from vegetables to shrimp shells, bones, and even rawhide without worrying about smell or vermin.

M L Jassy said...

I voted! The whole BSF thing is news to me but it sounds like a fantastic possibility to introduce. Enjoy the bucketeering.

Paula said...

So I voted, but still feel compelled to write you something. I've read about BSF larvae as a good food source for chickens, and decided that once I finally do get chickens, BSF larvae are in the plans as well. That's why last summer when I noticed BSFs hanging out in the corn, I recognized them for what they were and thought, cool, they're here already.

So I'll be looking forward to anything you post on them. Good luck with the knock off; I'm hoping to learn something from you.

Robert said...

Great Post about the Black Soldier Fly.

I'm truly fascinated by grub composting. My father and I developed the first BioPod™ and there is something I wanted to add to the concept.

We have figured out that given enough food waste, one square foot of grub composting can actually produce about 30 lbs of insect protein a year. As an acre of soys produces on average about 330 lbs of protein per acre, 10 square feet of grub composting could produce up to the equivalent of one acre of soy per year. That's an amazing change in sustainability.

Also another amazing discovery we have come aware of is that you can actually let the grubs mature into adult flies without ever knowing they matured. We recently met a lady that had been breading soldier flies into mature adults, not just the grubs. What was happening is that fly catchers, wablers, and other insect eating birds found a food sanctuary in her 1/3 of an acre property. The birds would literally hang out by her bin and scope down the moment one of them matured.

So if you are breading the grubs for animal feed or letting them pupate for the benefit of flying insect eating song birds, both methods unlock our food waste from the landfill cycle and within HOURS re-integrates it into our eco-cycle.

Robert Olivier,

Tamar@StarvingofftheLand said...

Damn you're good. The willingness to partner with an insect species to feed your chickens in a more sustainable way is what separates the men from the boys.

I'm a boy, I'm afraid. I think it's a genius idea, and your progress reports may well talk me into sucking it up and entering manhood, but it's just so hard to get excited about a black soldier fly!

I'll try. I will. And I will be forever grateful for your ideas and your example.

Hazel said...

This is fascinating! I voted and left a comment yesterday, but the comment isn't showing up. It'll probably appear now, and I'll be here twice...

DS (just 10, so not at all repulsed by anything in the insect world!) and I have been informally feeding larvae to the chickens and ducks over the summer, but they were blow fly larvae from not very well bokashi-ed fish remains in the compost heap.
I liked the fact it was free protein, and DS was very up for finding roadkill to feed maggots to the chickens in the way you'd mentioned before. That makes total sense to me, and I would have had a go if we didn't live so close to our neighbours, including the ones that are cross that we even have poultry in the first place...

So this sounds great- the same principle but without the smell. I've done a bit of googling too, and it can even be used to compost dog and cat faeces, which I still haven't dealt with entirely satisfactorily (I think I'd leave those larvae for the wild birds though). It sounds like a(nother) project for this summer. Oh dear...

Kate said...

Lynda, I look forward to comparing notes too. I have one bucket almost done, and plans to make one or two more. I'll probably have to wait several months before even trying to establish a colony though. Let me know please if you start sooner!

Arnica, sorry for the oversight. I really don't know anything for certain as applies to your location, but I have heard that some people were able to establish populations well outside of the BSF's native range. Might be worth keeping your ear to the ground to see what info turns up on that issue.

Annette, I'll post soonish about the buckets, and then again whenever I start the colony going. See my comments to Arnica about colder climates. It may not be impossible for you, especially if you have a hoop house or greenhouse.

meemsnyc, glad it appeals to you.

Christopher, welcome! I've heard of that feeding method too, from the same person who enlightened me about BSF. Unfortunately, he (Harvey Ussery) did have one of his chickens become ill from maggots from carrion. The risk may be small, and probably is. But based on my limited experimentation, the smell is not an inconsiderable issue, especially, as Hazel indicates, for those with nearby neighbors. So for my efforts I prefer to encourage the mostly vegetarian BSF, with its much lesser chance of becoming a vector for disease. Still, I'm glad to hear of folks making chicken feed from thin air.

Jim, yes, another nice attribute of the larvae is their incredibly energetic activity in a compost pile. They very much speed up the decomposition process, keeping the pile aerobic and therefore non-smelly. And if you have no livestock, it's not a bad thing to benefit wild birds, who will cycle phosphorous for you via their manure. Sounds like a win to me!

Mitzi, thanks. A bucketeer is me!

Kate said...

Hi Paula, Sounds like you'll have it pretty easy when you decide to start BSF bucket composting. I'm happy to let others learn from my efforts. I learn so much from the mistakes that other people have made and learned from. So guiding people around my own mistakes makes them easier to bear.

Hi Robert, thanks for stopping by. Interesting points on the potential output of the BioPod. I expect that food waste is actually going to be a limiting factor for us. We just don't generate all that much of it that doesn't go directly to the chickens. We shall see what we're able to accomplish with 2-3 bucket composting units. About the adult BSF...Are you saying that sometimes the insects complete their development into adults right inside the BioPod?

Tamar, you're pretty badass yourself with the hunting and oystering and all. So don't go selling yourself short. And anyway, would it make a difference if I told you that this is in large part about flavor? I know you've debunked the superiority of flavor from pastured eggs theory. But I'm staunch in my belief in that superiority nonetheless. I remain convinced that the eggs taste better when the hens eat insects. So having a steady supply of them is just my way of putting a better egg on my plate. Financial savings and ecological ethics is merely window dressing. Don't tell anyone!

Hi Hazel! Check my comments to Christopher, above. I won't get all paranoid on you about the blow fly larvae, but I am convinced there is a risk from that method of feeding, at least to the livestock. I'm all over free protein too, so I was disappointed to hear of the incidence of disease in Harvey Ussery's flock. I know him to be a meticulous and attentive husbandman, so I take what he's written about this seriously. Hadn't heard about pet feces for BSF. I'm not too sure I'd go that route either, if there were any alternative. But BSF fed with plant waste sounds eminently safe. Most pathogens prefer anaerobic conditions, and the larvae churn their food source so energetically that there's very little chance for those conditions to prevail. If you're committed to trying BSF this year, why not build a bucket now, during this "down time?"

Robert said...


when you don't have a biopod or specialized bin to channel the grubs for harvest, it's actually ok to let them pupate whereever they might pupate as you are contributing back to the ecosystem in a harmless way.

Hazel said...

Hi Kate, The pet faeces bucket idea would be solely to get rid of the waste. If we had more land or any purely ornamental areas I could have a separate compost area and it would be fine, but edibles end up all over the place in my garden so I need a method of disposal that leaves minimal residue. From what I've read biopod advises against using manure, but I think that's from a health and safety standpoint and I wouldn't be using those larvae in the food chain.

BSF does sound a much better option. I was going to make a 2nd wormery, but I think a BSF bucket may go on the list instead. That's the trouble with these quiet periods- I still end up with a do-do list as long as my arm!

grace said...

I voted the first choice, too. I found the larvae in my worm bin last summer and was pretty concerned that they were taking over my worms. But, I researched them, decided they were safe, and left them. They eat way more than the worms, I do have trouble keeping them all in scraps.
I am getting chicks this year and am excited to hear of the possibility of feeding them the larvae. Thanks for the great post!

Dmarie said...

hey, I'd never heard of such a thing, but clearly you have struck a chord here. good luck with your efforts!

Anonymous said...

I would love to talk to you about an issue that I feel is a hot topic in environmental news. I have written an article that I think your readers would be interested in seeing on your blog.

Encouraging grocery shoppers to branch out from their usual selections and to join the local food movement, will help us conserve the forgotten species, and create a more sustainable agricultural system.

Kori Bubnack

Kate said...

Robert, so are you saying the grubs will pupate right in the composting bucket if they don't find an exit?

Hazel, I can certainly see the dilemma if you have no better way of disposing of pet poo. I can't really advise there since our cats figure the issue out for themselves.

Grace, I understand that BSF cohabitates very well with red wriggler worms. They largely use different resources within a compost pile, so in a sense they compliment each other perfectly. Good luck with feeding them to your chicks.

Dmarie, thanks.

Kori, you're welcome to post a link to your article. I don't accept guest posts except from my husband, but I do sometimes post links to stuff I find online.

Zeal said...

Your post is great.
I want to know if BioPod could be used for Housefly Maggot production.
Looking forward to hearing from you.

Kate said...

Zeal, thanks. I'm afraid I can't answer your question though. I have no experience at all yet with BSF cultivation, let alone housefly cultivation. I recommend you check out blogs devoted specifically to BSF, and see if you can find a place to ask your question.

Ava said...

I live in zone 9 and the BSFL have taken over my compost bin. Food scraps are composted in 2 days and my chickens are eating about half the amount of commercial feed. It generates a lot of heat so the worms can't live in the bin anymore. It is amazing to watch, it is a pulsating mass of larvae. It's an easy way to compost because I no longer have to turn it.

bean said...

I have black soldier flys. I got them by accident last year when trying to start a vermiculture. I don't think their container has to be complicated. I just took a bee box super, screwed a queen excluder(screen ) to the bottom, filled it with putrid compost and put the lid on it sloppily leaving small openings for the adult to enter. My population is crazy huge. They break down massive amounts of food in hours. Meat, dairy, veggie waste. I noticed they love rotting citrus and citrus rinds (I'm in California and juice a lot of citrus. You would think it would kill them. Also feed them green walnuts that had been soaked in Vodka (Noccino experiment-yum!). Didn't kill them either. Last fall I experimented with putting cat poo from the litter box in there. Don't think they liked it, maybe too much litter got in, but it could also have been the time of year when they start to go dormant. Honestly, I think the rotting citrus is what originally attracted them. Recently I have had so many I have starting giving them to my chickens as treats. They go crazy for them. The chicken feeding frenzy is insane. I did have one chicken get sick though and I am hoping (especially from what I have read) that the maggot feeding is coincidental and not causal.

charlie said...

51I got black soldier fly pupae by accident. I set up a raabit hutch of about 20 cages. WE built a concrete block lined trough to catch the manure and thought we would shovel it out. Well, we've had our rabbits for months and there is never any manure to shovel out. We found the pupae working very actively. TPO bad I have nothing to do with them. Any suggestions as I dont have hens.

Unknown said...

Hi Kate, I am a student in Penn State and I am working on a research project of BSFL as feed addictive. However, all my flies were from CA cause I cannot find any locally. Did you get your grub from local population? thanks

Kate said...

Hi. Leave your email in the next comment and I'll be happy to reply to you privately. Your email will not be published.