This was originally published in the Hawai’i Homegrown Food Network newsletter on 21 NOVEMBER 2013; click here for that version. I have added some other photos to the blog that didn’t make it into the newsletter version.
Black soldier fly bin outside of chicken area.
The self-harvesting, antibiotic-excreting, protein-rich larvae of a beneficial insect could be the answer to cutting our dependence on imported animal feed.
Every time a new guest visits our chicken area, they ask about the big orange and purple bin with tubes hanging out the back. “That,” I say proudly, “is our black soldier fly larvarium. Want to see inside?”
They hesitate, and may say no. But for those who are interested, I lift the lid. Our guest’s body stays back, ready to run, while they peer in at the mass of wriggling tan grubs covering partly eaten compost. I point out the brown larvae crawling up ramps in the back of the bin, and describe how these are ready to pupate and looking for light.
Sadly for them, they will crawl out only to be eaten by the waiting chickens.
Whether you find them gross or fascinating, the black soldier fly (Hermetia illucens) may be able to close the loop on one of the weakest links in self-sufficiency here on the islands – the lack of local animal food. The larvae of black soldier fly are very high in fat and protein and are a huge favorite of chickens and pigs. They can also be fed to ducks, other birds, fish (best if dehydrated), and reptiles.
Larvae drop out into chicken area when they are ready to pupate or they can be collected in a bucket or other container.
Larvae provide a land-efficient, intensive food source ideally suited for regions with limited farmland for growing grains. In just one square foot of grub bin you can produce35 pounds of protein a year. To get that much protein from soy, you would need one-tenth of an acre. Farming larvae instead of purchasing grain of course saves the cost of imported grain, which can be two to three times higher than on the mainland, plus you haven’t contributed to burning fossil fuels to import grain.
Black soldier fly adult laying eggs. The adults hang out in trees and live less than a week. She will lay 500 to 1000 eggs.
Black soldier fly are different from other flies in several ways that make their larvae the best to raise. Most importantly, they are not a disease vector, because in their short life as adults they do not eat. They don’t even have mouths. When the larvae are ready to pupate (around 2 to 4 weeks after eggs are laid), they secrete their digestive system, lose their mouth, and produce an antibiotic coating. Therefore, unlike house flies, they cannot carry disease between wastes and foods we plan to eat. This also makes them safe to feed to our animals.
Young larva (left) and older larva (right) still in their pale phases, not yet ready to migrate out of bin. Grubs go through 7 stages before pupating. Just before pupating they turn brown for better camouflage; this is when they are best to feed to animals.
Soldier fly larvae are very rich in protein and fat. They contain 34% – 45% protein, 42% fat, 7% fiber, and 5% calcium, which is critical for strong chicken eggs. Research has shown that larvae fed fish waste are higher in omega 3‘s and that this translates to higher omega 3‘s in chicken eggs (described by Olivier, see References).
Larvae can be fed agricultural and slaughterhouse waste, converting a potential pollution problem to a food source. Fish waste, cow pies, and papaya are great larvae foods. The only things they don’t eat are tough and woody items such as avocado pits, coconut husks, and bagasse (sugar cane stalks after being pressed).
We feed our larvae the compost that the chickens don’t eat directly. This season our larvae bin has been getting a lot of rinds from citrus, jackfruit, ulu, and lilikoi, excessive banana peels, and bad avocados. The larvae also find corn cobs and pineapple skins delectable. Coffee grinds help control the aroma.
A picture of three life stages can be found here http://blacksoldierflyblog.com/bsf-basics/
So You Want to Be a Larva Farmer
Soldier flies are common in Hawaii and active year-round, so you should be able to attract them easily with some odorous compost. The exception is if you live where it is colder than 75 degrees at the hottest time of day. If you see active bees, then you should have soldier flies.
You can either make your own bin or purchase a “biopod” on-line (see References). Biopods have drainage plates and other helpful features, but cost over $200 and do not have a distributor on Big Island. They can be shipped from Texas for around $80.
A good chicken food ratio is one third grains, one third insects, one third greens and fruit.
If you make your own, the basic criteria are to create a dark lidded bin with an internal ramp with a pitch of at least 30 degrees (this is so house fly larvae can’t get out) that empties into a bucket or directly into your chicken area. Screened drainage helps keep the contents from getting too wet. Start the bin with the lid open and add a few handfuls of compost to attract females. Once you see a female, you can close the lid. You will have fruit flies and house flies at first, because their eggs hatch quicker than soldier flies. Once the soldier fly larvae are established, they dominate their competitors, and other flies stop being a nuisance.
Black soldier fly larvae collecting in bottle. Having stored up plenty of fat, the larvae can survive for 7 days looking for a good place to pupate.
To feed 8 to 12 chickens, add around a square foot of compost per day. This should yield around one pound of grubs in several weeks, depending on temperature and daylight length. See what your bin can handle – if the waste is mostly uneaten from one day to the next, adjust by adding less compost. If it gets too wet and stinky, improve your drainage and add dryer compost. If it is too dry and ants are colonizing the waste, add damper compost. Do not go over a depth of 4 inches of waste unless you have at least 1 inch of grubs in there.
Around 5% of food waste is not converted into the larvae’s bodies and is left as compost. Although this is not as rich in nutrients as worm castings, it still is a useful fertilizer and has been used for growing orchids and mushrooms. When you want to clean out the bin, stop feeding until the last grub crawls out, and use the remaining compost.
Happy grub farming!
Resources
Much of this information is from Natural Farming talks presented by Robert Olivier in October 2011 – “Why Farm Insects” and “Raising Black Soldier Flies” : http://naturalfarminghawaii.net/2011/10/black-soldier-flies-presentation-by-robert-olivier/
Robert Olivier’s website from which you can buy larvae bins and composting supplies: http://www.compostmania.com/
For purchasing biopods on Oahu ($210): http://kokuaworms.com/ and http://kokuaworms.com/the-bio-pod/
General information: http://blacksoldierflyblog.com
SORRY IF YOU SEE AN AD BELOW, NOT MY CHOICE, BUT THAT’S WHAT I GET FOR NOT PAYING FOR THIS BLOG SPACE!
December 15, 2013 at 2:37 pm
Hi! I hope this is Rachel reading this….I have been trying to no avail to find your email to contact you in regards to WWOOFing on your farm sometime in late spring. If you are still looking for willing workers sometime between March and May please contact me at readtttt@hotmail.com
May 19, 2014 at 7:49 pm
Aloha! Thanks for the post, I was wondering if you could share pics of the inside of your “big orange purple bin.” Also what do you suggest for compost to attract the flies and about how long does it take?
May 22, 2014 at 7:26 am
Aloha Travesty, glad to hear you are gearing up to grow some larvae! I will add some photos of inside the bin, although they are not that pretty, but since you asked… okay. The flies are particularly attracted to rotting fruit or animal carcasses – if you have some raw fish skin/bones, that’s a great starter. If you are in Hawaii I would expect the flies to find your compost lure within 1-2 weeks, then they lay their eggs and larvae will hatch in another ~2 or more weeks. The eggs are tiny little white clusters, so you can look for those to feel encouraged, because it can be slow starting up. Other flies (fruit, house) are faster to hatch than the black soldier flies so you need to be patient, as you may not see the black soldier fly (BSF) larvae for a month. Fruit and house fly larvae are smaller, smoother and wriggle faster. (Which you will learn from observation but is hard to judge if you’ve never seen the BSF larvae!) Okay I will post a photo or two and update that same blog post now…
May 22, 2014 at 8:59 am
Thanks!
October 18, 2014 at 12:11 pm
This site was… how do I say it? Relevant!! Finally I’ve
found something which helped me. Thanks a lot!
October 18, 2014 at 1:13 pm
Great, thanks!
A general update – our bin has been going extremely well thanks to an arrangement we have with a local organic juice bar/restaurant. We get their compost and sort it out so the larvae get the citrus rinds and the chickens get most everything else. This is perfect because the larvae really do love the citrus rinds. That plus the occasional trapped mongoose have kept the bin going at an excellent clip. The larvae are not constantly migrating out, however; they come out in waves, about once a month several hundred turn brown and climb out. I am not sure why this is when it seems flies could be laying eggs in there more often than once a month. Do they have some chemical signalling that coordinates or limits the egg laying to once a month? Or are there environmental factors that synchronize larvae development?
November 22, 2015 at 9:32 am
I started a homade bsf bin about two weeks ago. I saw one bsf in it the second day, also a few fruit flies and house flies. Two days later I saw my first tiny white grubs. I have no idea what kind of grub they are. I have not seen a house or fruit fly in the bin since. How long will it take me to know for sure if I am raising bsf in my bin?
November 29, 2015 at 8:50 am
(Thought I replied but it seems to be gone now so I will reply again)
Soon! Should be within the third or fourth week from when you saw the BSF, depending on temperature and when the eggs were laid. Grubs that stay small and wriggle very fast are not BSF. Any update?
November 29, 2015 at 9:35 am
The bin was started on Nov 15th. 1st grubs seen on 18th. 29th grubs are about 1\2in or more. There are also some smaller ones. I spotted some small oblong brown casings about 1\2 cm long in the box. At first I thought they were pupae casings of some other fly. Now I just don’t know. Any ideas? The temp here in the DR is 70 at night and high 80’s to low 90’s day.
November 29, 2015 at 10:04 am
It sounds like those 1/2″ grubs are BSF! Pretty sure the others (fruit, house) would have pupated sooner, they just live for a few days as grubs before pupating. The brown pupae could be houseflies, but i don’t know for sure – sounds like soon if you keep being this observant you will know the lifecycle of all the critters in there!
November 28, 2015 at 7:28 pm
ALOHA! Thank you for posting this article. We just got 2 hens and are looking for natural and alternative food sources. We live on Oahu and just wanted to ask if there are soldier flies here on Oahu. I don’t recall ever seeing them. The idea of raising food for our chickens as well as putting a dent in our housefly population is exciting for us! Mahalo for your insightful article!
November 29, 2015 at 8:44 am
I’m sure there are. Just put out some compost in any covered container, leave a crack, and they will find it. If you have a fish carcass or some other meat scrap in there, all the better. Good luck!
December 19, 2015 at 3:57 pm
[…] years ago I wrote about how we raise black soldier fly larvae to provide protein, fat, and calcium for chickens. Since writing that blog, we have […]
September 2, 2016 at 10:10 am
i bought 1500 grubs online and placed them in a biopod, question is will the grubs reproduce on their own? I live in the southern California desert, not sure how the bsf need to be present to continue this grub farm..
September 2, 2016 at 10:29 am
If you let some grubs pupate (look for little brown pills) and hatch as flies (they look like black wasps), and if they have some shrubbery or trees to go hang out in and mate, and then can get back into your biopod to lay eggs – then the cycle will continue. Larvae will pupate if they have a dry area, either in the biopod or outside of it, where they won’t get eaten. Good luck!
February 18, 2017 at 1:22 am
hallo!!!is there any chance to farming this insect in Bangladesh…is it economical???
January 2, 2019 at 4:39 pm
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September 20, 2021 at 9:37 am
hi,
i have started new farm in pakistan, where we are producing larvae on experiment base,this article help me alot.
thanks