Black soldier flies are common in tropical and subtropical regions, but their range extends to the most northern states of the continental U.S. You can easily operate a BSF bio-composting unit in northern states during the warm months, but you can also maintain the colony through the colder months with a little extra effort.
A black soldier fly colony generates its own heat
Maintaining a BSF unit in cold weather is possible because the metabolic action of the larvae eating creates heat as a byproduct. Under cold conditions keeping the colony at the optimal temperature range of 85° - 100°F (30°-38°C) is as simple as consistently feeding them and placing an insulating material directly on top of the pile. Simply remove the insulating material, add the food scraps, and then replace it. It’s important to feed the colony consistently in cold weather because without food the temperature will drop and the colony will become dormant. If the larvae are exposed to freezing temperatures they will die. Also, any insulation on top of the colony needs to have an air gap between it and the BioPod.
Maintaining a BSF colony during extended periods of sub-freezing weather is possible, but it may be more than you wish to get involved with. In that case you can enjoy BSF culturing up to the point where the weather in your area makes it difficult and then resume in the spring.
Process more food scraps, harvest less larvae
In cold weather the time it takes BSF larvae to mature increases from the usual few weeks to a period of up to several months. The colony has little or no crawl-off of mature larvae and that enables you to continue bio-composting without the need to replenish the larvae via visiting females.
In warm weather the colony has a tendency to overheat, so in cool weather the larvae are able to consume even more food scraps.
How adventurous are you?
I don’t recommend bringing the BSF unit into your living room, but why not try keeping it in the garage or a shed when the temperature drops? Sure, a few larvae might get out, but so what? The adult fly will just emerge from it’s pupae in the spring and then you’ll have the pleasure of gently capturing it and releasing it outdoors. They are harmless creatures after all. I don’t think a heated space would be the best choice though, because it might trick the larvae into developing too quickly. I would guess that 40° - 60°F (5°-15°C) is a good range to try testing this theory, and of course you would need an insulating disc of some sort to keep the colony warm. The degree of insulation would depend on the ambient temperature in the space.
I’m cursed with living in an area that rarely gets cold so if you try this experiment please let me know how it goes. I would love to post photos of your set up (if it works 
).
Comments 20
Wow, this is interesting information! (liked the picture caption that came with the post too :D) Is this heat-generating ‘feature’ something that applies to all flies or just Black Soldier Flies?
Posted 18 Aug 2008 at 10:28 pm ¶Thanks!
I’m not sure if other fly larvae create heat this way. It shouldn’t be difficult to find out though, because there has been a tremendous amount of research done with house flies. There has been a relatively small amount done with BSF, but I’m sure some of the research translates.
I’m glad you like the photo. I took it during a cold snap in New Hampshire this last January while visiting friends.
Posted 18 Aug 2008 at 10:37 pm ¶@Jerry: Firstly, you officially win the title of ‘fastest comment replying admin’ ever! I was clicking back onto the homepage to see what new posts I had missed reading and saw ‘2′ comments. I thought I had double-posted!
Secondly, sorry to be a pain, but would it be possible to provide a ref link to the research about the temperatures quoted in the article please?
Looking at the picture really makes me shiver already, haha
I love panoramic shots! Maybe you could persuade your friend to do a mini BSF experiment?
Posted 18 Aug 2008 at 10:42 pm ¶Don’t worry, most of my friends are “pains”.
I’m just glad you’re taking an interest in BSF.
I should have included links in the post to begin with and I’ll add them soon. Here’s one of the links I used (I need to find the other):
http://www.esrla.com/brazil/frame.htm
This presentation is a few years old but contains some great data. It was compiled by Dr. Olivier who developed the BioPod. If I got any numbers wrong please let me know, I was a little tired when I wrote this post.
Also some if it is conjecture on my part, but I think that’s clear.
Posted 18 Aug 2008 at 11:06 pm ¶I’m interested in cultivating BSFL, for my chickens. I live in frigid Wisconsin, though. If I tried it, I would be keeping the colony in the chicken’s “room” in our hangar. Yes, we have an airplane hangar, it’s basically a giant unheated shed. The chickens are in a room in one corner, the walls are insulated but the ceiling not so much. They have an opening to the outside that I close off when it gets bitterly cold. I have to keep their water container on a special heated stand to keep it from freezing, so that’s how cold it gets in there. I suppose I could buy another one (it’s just a metal tray with a wire taped to the underside that is set to heat to about 35 degrees, I think) and put it under the colony, but I don’t think the shape of a biopod is conducive.
If the larvae go dormant, can they freeze and come back?
Posted 24 Aug 2008 at 9:56 am ¶I’m fairly certain that freezing will kill larvae or pupae, although my knowledge about this is limited. There seem to be wild BSF populations in areas that experience prolonged periods of freezing temperatures so they have some way of surviving. They couldn’t pupate underground because the emergent adult couldn’t dig to the surface.
The same factors that allow the juvenile larvae to survive in cold weather, metabolism plus insulation. might allow pupae to survive in similar conditions. Perhaps the prepupal larvae find sites that provide some insulation and then generate heat through the process of pupation. Ultimately I believe they would have to maintain above freezing conditions inside their shell. I imagine less larvae successfully pupate the further north you are.
DrFood, you may be able to overwinter BSF larvae and pupae in in your hanger without a heat source. I would try elevating pupae a few feet off the ground in a box with sawdust or a similar bedding material. It’s possible they would even mate inside the hanger. I think the hanger would also make a BioPod easy to operate in winter with an insulating disc directly covering the pile.
Posted 24 Aug 2008 at 12:35 pm ¶I am thinking about buying a BioPod, but I may have to restart it every spring with new BSF’s. I remember reading about some folks that were using a repurposed freezer to keep their BSF larvae above freezing, but I’m not THAT into the idea! I can only imagine how icky a chest freezer could get after housing thousands of sacrophages for a few months–and it’s too big to just tip over and clean.
Still, the BioPod is intriguing. I have a dozen hens, and I think it would be great to provide them with a high quality live whole food. If it works really well, I might try to obtain food waste from my hospital or a local school cafeteria. I am not above dumpster diving–I’ve done that many times!
Posted 24 Aug 2008 at 4:50 pm ¶First, I have to say that I appreciate a dumpster diving doctor.
I don’t think you would need to go to great lengths to overwinter BSF pupae. All they need is to remain above freezing with humidity around 40% or more. (That percentage is an educated guess.)
With your semi protected space it should be simple to maintain an actively feeding colony through the winter. BSFL generate a lot of heat as they metabolize food. A little insulation and a daily supply of food for fuel should do the trick.
Posted 24 Aug 2008 at 5:02 pm ¶I have a couple of questions regarding the use of the BF on farms. I am a little concerned that the BF will utilize manure (poultry) that is piled for other uses. Does the BF have to have a certain moisture content? If so, I can control manure access via having it under cover with no extra moisture. This way I could have a ready pile of manure that I could feed the BF growing chamber, just adding a little moisture. Will poultry manure be a good sorce of feed for BF? How about other things like guts and other stuff you get when processing birds?
Thanks in advance for your information.
Tom
Posted 28 Aug 2008 at 11:52 pm ¶Hi Tom,
I think BSF will colonize any available pile of manure that’s accessible, even if it’s on the dry side. It might make a difference if you live in a very dry climate, I’d have to think about that. BSF are very common in chicken manure, but I don’t know of anyone who has ever processed it in a BioPod or similar device. I’ve only processed whole fish, but I would think guts would be great food for BSF larvae.
I’m curious if your main goal is to reduce the manure/guts volume or to raise the larvae for feed. BioPods are sized for the average amount of food scraps generated from a typical household and wouldn’t be practical for more than a small poultry operation. If you want to raise a pound or so of tasty grubs for a small flock a BioPod should work fine.
One possible problem with using chicken manure in a BioPod is that when BSF larvae process chicken manure it turns it into a liquid. I think it would be pretty messy. Also there might be a problem feeding larvae back to the same species of animal that generated the manure. I’m not sure about that but I would check into it before setting up a system.
Let me know if you have more questions.
Jerry
Posted 29 Aug 2008 at 8:17 am ¶I want to use poultry manure to feed the BSF then feed the BSF to tilapia. I do have a litter shed with a lot of poultry litter in it and am worried about it being liquified but I am in TN and have never had this problem, maybe because the litter is relatively dry. It has the consistency of dried sawdust. I have never seen a liquification problem and I am wondering why BSF were not already there. I am in southern middle TN so maybe there is a geographical reason.
I would like to design a larger BSF system for larger volumes but am very happy with starting with one of your systems.
Eventually, I want to have laying quail. I could design a system where the quail pens are over a BSF system where the droppings just go to the BSF bin. I could then harvest BSF larvae for my tliapia which are in a different building. I would appreciate a little help with that idea with requirements for BSF larvae in mind. They may require additional feeding, for example. Before I do that, I would like to try one of your BSF systems to get a handle on the requirements of the larvae.
Thanks for all the information.
Tom
Thanks for your help.
Posted 29 Aug 2008 at 8:31 am ¶Since the litter is that dry it might not attract BSF. I’m pretty sure BSF are present in your area and I know of a population of them between Nashville and Chattanooga. The risk of BSF getting into the dry litter will increase if you maintain a colony on your property. If you try raising BSF you might want to do something to prevent the adults from accessing the stored litter.
Having BSF grubs to feed to your fish would be great. I would do some research before feeding BSF larvae raised on poultry manure to other species of poultry.
From what I understand you should be able to raise BSF on just about anything that has some nutrition except for grass, paper and other high cellulose items. Different food sources will effect the size and development period of the larvae, but the items you’re talking about should work fine. I think there is evidence that BSF don’t thrive on aged swine manure. I’m not sure how that information might effect you, but I wanted to mention it.
You might learn something useful from this study:
USING THE BLACK SOLDIER FLY, Hermetia illucens, AS A VALUE-ADDED TOOL FOR THE MANAGEMENT OF SWINE MANURE
Posted 29 Aug 2008 at 9:00 am ¶It seems to me, and I am just guessing, that some of the reasons of your concern of feeding BSF larvae to poultry when they were raised in poultry waste include the possibility that the BSF is using the nutrients in the poultry litter that the poultry did not use. If you have developed a well formulated poultry feed, the poultry will utilize most of the nutrients as well as they can in one pass through the gut. BSF just get the last bit out of undigested feed and nutrients. Another concern might be pathogens in that particular specie being passed on and actually magnified because they are around that specie more. Feeding BSF raised on poultry manure and fed to tilapia don’t have the same vectors of transmission. Thus, waste by fish can conversely be transformed by BSF to be used in poultry applications. There may also be some other nutrients utilized by poultry or in different forms that fish and or BSF do not use in their biology.
I will note that poultry by product meal is available in poultry rations which includes feather meal. The processes for these feeds usually kills the possible pathogens related to those animals. The whole bse (mad cow disease) does bring some concern over canibalistic forced feeding (which is what we do when we provide feed). Some species have no problem with this but they are mostly carnivores or in the least, omnivores. Bass, for example, will eat their own kind but are carnivores. Tilapia, in their lives are more to the herbivore side but have some omnivore characteristics at certain stages.
The thing that interests me over BSF is their ability to transform waste into a useful product and with your help Jerry, in an economical manner. Usually this takes a more complex and less understood biological action on the micro level (composting for example) where the nutrients are still there, but must then go through another vector (through plants again).
When I first looked into the BSF I was warned that they are more trouble than they are worth with their liquification problems. Maybe this isn’t a real concern as I have not seen it on my farm in stored manure. If we have a native population with any access to my manure (which you say there is a population near me in Lynchburg TN), I don’t need to worry about that concern.
I am particularly interested in BSF because they are high in methionine (by the cited studies) which is a limiting amino acid in poultry rations. This usually comes from an animal source (like insects). BSF provides that.
Another limiting amino acid in poultry rations is lysine. Any ideas of more natural ways to get lysine in a ration?
Thanks,
Tom
Posted 29 Aug 2008 at 11:41 am ¶Thanks for the great comments Tom.
I can’t tell you much about lysine, but BSF meal fed swine and beef manure is compared to soybean meal for this amino acid. Check page 8 of the study I linked to for that data.
I have to admit that I’m a hobbyist and not a scientific researcher, so I’m more of a student than a teacher at this level. I’m happy if you pick anything useful out of my brain.
Posted 29 Aug 2008 at 11:59 am ¶When you talk about insulation, do you mean outside the biopod? Not inside, right?
Posted 06 Oct 2008 at 11:49 am ¶Thanks!
Hi Imani,
I suppose it doesn’t matter how you keep them warm, but the simplest method would probably be an insulating disc inside the unit, directly on top of the pile. The disc must have a gap around the sides for oxygen and also to let the grubs come above the insulation if it gets too hot beneath it.
Styrofoam is good insulation but the larvae will break up the unprotected material so it needs some type of cover. I haven’t tried using such a disc yet but I will be working on one soon. I think I’ll try including some type of convenient handle to facilitate removing the disc when adding food. An important aspect of cool weather biocomposting is regular feeding because food is the fuel that the larvae use to generate the heat they need.
Thanks for your comment Imani and good luck!
Posted 06 Oct 2008 at 12:19 pm ¶How can I start a colony in the fall or winter periods if I don’t have any BSF flying around right now? I’m anxious to get going with these, but don’t want to wait until Spring?
Posted 10 Nov 2008 at 9:57 pm ¶Hi Daniel,
To establish a decent colony of BSF larvae you need breeding to occur which doesn’t happen in cold weather. BSF become relatively inactive when temps drop below the mid 70’s.
You can buy the larvae as Phoenix worms but they’ll be extremely expensive. An order of 1200 costs $59 from phoenixworm.com and will only amount to 2-3 cups. (Their website mentions this quantity as “12 cups”, but they don’t mean a true 8 ounce cup of larvae) Compare that to the 50,000 or more larvae that can make up a colony in a 2 ft diameter BioPod and you can see that it’s not very practical. I doubt a few thousand larvae could generate enough heat to thrive in cold weather even with insulation. You could work with a very small colony but I think you would have to find a way to keep the unit consistently warm.
Maybe you could keep a few thousand indoors for the winter and then move outside with the BioPod in the spring.
Posted 11 Nov 2008 at 11:57 am ¶Jerry, it seems to me you could put them in a box or enclosure with a heat producing light in it like you would keep just hatched out birds. What about warm heating pads that you use for lizards? Just keep thinking about it and the answer will come. Make it a kid’s science fair project! I don’t think the larvae like light but what about the infa red lamps?
The Phoenix worms may just be a way to start a colony, not benefit from it in the long run as in the long run you need your own breeders to come back.
If you did keep them in some kind of a set up, could you keep them there and would they breed? Do they need to fly to breed and if so, how big of an area does it require?
It seems to me that the BSF will produce a lot of babies even in the fall, so keeping their babies alive is what you want.
By the way, Jerry, if you grow BSF are they considered Organic Feed by the Organic Standards Board?
Thanks,
Tom
Posted 11 Nov 2008 at 12:34 pm ¶Hi Tom,
Yes, the larvae would do fine as long as they have food, warmth and moisture. They tend to avoid light in general, but they can always hide under the food scraps in the compost. It’s not unusual to see them on the top of a food pile in the daylight.
The BSF won’t breed in a BioPod or similar unit. The adults mate in flight and won’t do so unless they experience natural light in the proper cycle. They have been successfully bred in outdoor screen enclosures measuring 10 X 10 feet. They haven’t been successfully bred indoors to my knowledge.
Each winged adult BSF female will lay from 500-900 eggs in her short life of only a few days. I did have some egg laying in south Georgia during the month of October, but it was much less than during the summer.
I don’t know about BSF larvae being organic feed, but I would imagine it would depend on what they’re raised on if they’re in a controlled environment. Organic in/organic out?
Posted 11 Nov 2008 at 12:45 pm ¶Post a Comment