Skip to content

BSF questions and answers

Here are selected emails I’ve received and my best shot at the answers.

  1. BSF in a tumble composter, separating BSF from soil
  2. How to initially attract BSF (in Kentucky)
  3. BSF grubs disappearing from homemade unit
  4. How to maintain colony while harvesting BSF grubs
  5. Processing pet waste
  6. Concerned about BSF grubs in compost and possible “infestation” from adult BSF
  7. Difficulty establishing BSF in Michigan
  8. What to feed to a BSF colony
  9. Limitations of feeding manure-raised BSF grubs to animals
  10. Trouble shifting BSF from compost pile to BioPod
  11. Protecting BSF grubs while establishing a colony
  12. What to do with harvested grubs if you don’t have animals to feed
  13. Containing BSF that are migrating out of a worm bin
  14. Starting in an non-native area, concerned about BSF pestering neighbors
  15. Can I automatically harvest BSF larvae from a worm tower?
  16. Not seeing the reported repellent effect toward pest fly species

1) BSF in a tumble composter, separating BSF from soil

I bought my first composter in June. It is a tumble
composter that I added a bacterial accelerant to
and mixed greens and browns into. I think I used a little too many
wet greens as I now happen have a well established BSF colony! I
have three questions – first is should I continue tumbling, or do I
leave new food scraps on the surface? Second, do BSF eat corn husks?
And lastly, how might I separate the newly processed soil from the
BSF so I can use it in a garden? Thanks!

I don’t think that continued tumbling will hurt the BSF grubs, but if the scraps get buried more than 6 or 8 inches the larvae might not eat them.

BSF can’t process cellulose so I doubt they’ll target the corn husks right away, but It’s possible that they might work on the husks once they decompose some.

If you’re worried about the BSF larvae causing problems in the garden I can’t imagine what harm they would do. They aren’t designed to eat living plants or fresh vegetables so I don’t see any problem with adding them along with the compost. Having said that, if you want to separate the larvae you could put fresh food scraps in one corner of your unit and that should concentrate them for manual removal. They are especially fond of coffee grounds. You could also try this method: Collecting the immature larvae The dark brown larvae are the final larval stage and they don’t eat so you can’t attract them with food. If the walls of the container are damp or at less than a 45° angle the mature larvae will migrate out on their own. The mature larvae could also be added to the garden without a problem.

2) How to initially attract BSF in Kentucky

How, specifically, do I get started with black soldier
flies? I don’t recall seeing them in my area (W. KY) but that doesn’t
mean they’re not here. How do I target attracting them in order to
get a colony started? Thank you!

Probably the simplest way to start a BSF colony is to start a traditional compost pile and make sure that you always have some amount of fruit and/or vegetables present in it. Most of the people who accidentally discover BSF do so in their compost piles. I would also ask anyone I know who might have a compost pile if I could check it occasionally. If you know someone at a feed store that might be a good source. The store might not want to admit it but BSF often get into open or damp grain stores. Alternatively you can maintain some kitchen scraps in a bucket until they show up. That’s how I started. Here are a few links to my early experiences:

http://blacksoldierflyblog.com/2008/05/24/my-first-black-soldier-fly-colony/

http://blacksoldierflyblog.com/2008/05/24/first-attempt-to-attract-bsf/

My neighbor inadvertently started a colony in a bucket of dried seed corn that had partially filled with rainwater. Basically if they’re in your area they will eventually find rotting food. The more consistently you make food scraps available, the more likely you are to get BSF. I’m almost sure there are BSF in KY, especially if it tends to be humid during the summer.

3) BSF grubs disappearing from homemade unit

Hello…We have a homemade “Biopod”(with curving ramps)&
twice have had lots of grubs in it, but then they mysteriously
disappeared. We aren’t positive they were BSF, but we did find an
adult a few feet away. We live in Hawaii, but it wasn’t hot & the Pod
is in the shade. There are lots of little ants in it–will they eat
the grubs? Or would chameleons enter through the small air holes to
eat every last one? Or could it be that they were housefly grubs that
flew out the air holes when mature? They were large, cream-colored, &
looked exactly like BSF grubs. I would really appreciate your help to
solve this mystery–our chickens are waiting for grubs on the menu.
Thanks for the awesome website! Aloha, Wandalea

I expect that the grubs you have are BSF. If you’ve looked at photos of BSF grubs I think you’ll be able to tell them apart from the smaller housefly larvae. Also, if it were houseflies you would have a noticeable number of adult houseflies around your unit. If they are a BSF colony then they will have a repellent effect on houseflies and you won’t see many of them near the unit.

Do you ever notice them on the outside of your BSF bin?

When they disappeared was it all of them or just most of them?

Did your collection bucket catch a lot of grubs at the time your colony was reduced? Where those grubs dark or light colored?

Is the humidity consistently high in your part of Hawaii?

Are you in a cooler high elevation?

When the humidity is very high, such as when it’s rained, you will often have condensation on the walls of your BSF unit. In that case it’s likely that the grubs could crawl straight up the walls and exit through any holes in the unit. The way a BioPod is shaped makes this much less likely because it has a lip molded into it that only the smallest grubs could get past, and the small ones tend to stay with the colony more.

If your colony was reduced because of grubs escaping it’s not too bad in the long run. Some of the escaped grubs will survive and mate, and the resulting females will probably come right back to your BSF unit to lay their eggs. Of course many of the escaped grubs will be eaten, and unfortunately not by your chickens. Since my old unit was on the sawhorses I placed some containers on the ground beneath it to confirm that many grubs were exiting the unit and dropping to the ground. Have you considered moving your BSF unit to where you keep your chickens? The adult BSF could still fly in to lay their eggs and any grubs that escaped would be caught by your chickens.

It’s possible that the ants are at least part of the problem. The BSF grubs are very tiny when they hatch and even a small ant could carry one off. The ants might also be competing for the food scraps. I started with a homemade unit and I kept it on a pair of sawhorses, off of the ground. Occasionally I would spray the legs of the sawhorses with insecticide which kept the ants out of my unit. An alternative to chemicals would be to set the legs in containers of water. The BioPod manufacturer recommends treating the legs of the BioPod stand with Tac-Gel which I believe is some type of sticky insect repellent. At least with that type of product you would only need a small amount and you would have good control over it. Using insecticide on the ground near the unit would work against the ants but it would also hurt any BSF grubs in the same area.

The lizards could also be part of the problem, although I would expect them to have a constant effect instead of causing a large scale reduction in a day or two. I had tree frogs living in my homemade unit and they were obviously well fed. I took them out regularly, but they always returned. If your vent holes are large you might have some other type of predators entering the unit, eating your grubs, and then leaving. There is a long list of animals that eat BSF grubs. I haven’t seen any frogs inside of my BioPod but I do sometimes see one on the lid. I always move those frogs far away from the BioPod because they’re probably eating BSF females which have been attracted to lay eggs. If the frog eats several BSF adults that represents the loss of thousands of BSF eggs/grubs in the BioPod. I doubt that a few frogs would have a great impact on the colony in a BioPod, but I would move them anyway to maximize my colony.

Thanks for the kind words about my blog. Please keep me posted on your progress.

Aloha,
Jerry

4) How to maintain colony while harvesting BSF grubs

Hello-
I know that somwhere on your website you probably explain how to keep
the colony thriving even though it looks like all the larvae get
harvested. Can you clue me in? Also, is there anyone in Massachusetts
who has a successful colony?
Thanks for your help!

I don’t have first hand knowledge of a BSF colony in Massachusetts. BSF have been found in the wild in Canada so I think it’s possible they’re there.

BioPods aren’t fully contained systems in that the pupation and mating take place outside of the unit. Female BSF will seek out rotting food to lay their eggs near, even more so if there is an active colony of BSF grubs already in the pile. If you harvested every grub produced in the BioPod you could still have wild BSF coming to lay eggs in the unit. Of course letting some grubs go free will strengthen the wild population and increase egg laying in the BioPod.

Please let me know if you have more questions.

Jerry

5) Processing pet waste

My new Bio-Pod seems to be functioning, there are a zillion little grubs in there munching away on the food scraps. I was planning, however, to use it also for dog and cat poop, and was disappointed to see in the Bio-Pod Guide that the home unit was not suitable for this because of dangers of disease, etc. We have always composted our dog poop (but not the cat) with no problems. So I’m wondering how hard it would be to build some sort of container that I could use to digest the dog and cat poop (we use wheat litter for the cats) separately and just dump in some of the grubs from the Bio-Pod to get it going. Are there any plans anywhere for homemade units? I guess I would just use the mature grubs from that one to feed to wild birds, not our chickens. The point is mostly to get rid of the cat litter and doggie doo without sending it to the landfill. I could let it drain onto the ground, I guess under the trees away from our garden. Maybe I could make it so it just let the mature grubs crawl out onto the ground for the birds too. It’s a bummer not to be able to feed them to the chickens tho, that was my main reason for buying the Bio-pod.

The reason the BioPod manufacturer says not to process fecal matter of any kind is because of liability issues. Anytime you handle poop there is a risk of infection. Processing pet waste with BSF is probably similar to cleaning a toilet, you keep your fingers out of your mouth while doing it and you sanitize yourself afterward.

You certainly could add pet waste to the colony and they would process it easily. As with any type of waste you would want to make sure you didn’t overload the colony with a large amount at one time. Of course if you added any type of manure you would have to expect a certain amount of odor which isn’t usually an issue when you process kitchen scraps.

BSF that have been raised on animal waste have been tested as animal feed in several studies. Often in these studies the grubs were sanitized by cooking or drying before being fed to animals, but not always. I’ve read that if you raise BSF grubs with manure, that you should not feed those grubs back to the same genus of animals. For example, if you raise the grubs on mammal waste you could feed them to birds, reptiles, and fish. If you raise them on chicken manure you could feed them to mammals, reptiles, fish, and so on. My knowledge about this is limited, so you should do some research before taking any action.

Thanks for your business Harmon, I’m glad to hear that your BSF eggs hatched and are thriving. Let me know if you have any more questions.

6) Concerned about BSF grubs in compost and possible “infestation” from adult BSF

Hi, Thanks for the blog, lots of useful information and I’m now a bit more reassured about the hundreds of grubs wriggling away in my balcony compost.
However, despite all the good they are probably doing to my compost and the fact that we now have no flies buzzing around it, I’m a bit concerned about what will happen next. the compost is on my balcony so I’m worried that we are soon going to be infested my the adult flys or that my compost will always be full of the grubs – there isn’t actually any of my compost that doesn’t have grubs, so I can’t use it to fertilise or repot plants.
Any advice on how to remove them or reduce their proliferation would be helpful otherwise I fear I’m going to have to throw out all of my compost.

First let’s address your being infested with black soldier flies. I’ve raised and released tens of thousands of BSF grubs on my property over the past few years and I’ve never seen more than about a dozen of the adult BSF at any one time. In addition please consider that I’m always involved in trying to attract them. The reason they’re relatively rarely seen compared to other fly species is that their life cycle is different. Adult houseflies live for up to 30 days and during that time they need to eat of course. BSF adults only live for 5 – 8 days and they don’t eat during that period. They’re sole purpose as adults is to mate and lay eggs. When a BSF adult is attracted to any type of waste it’s almost certainly a female looking for a place to lay her eggs. For that reason the male half of the BSF population is almost never seen at all. Then, after laying her eggs the adult female BSF has no interest in the food source so she simply leaves and shortly dies. That’s the long version of “you won’t get an infestation of adult BSF”.

I’m glad that you’ve observed how BSF repel houseflies and other pest flies. That’s something I’ve addressed many times, but it’s nice to have confirmation of that from a third party.

You certainly can use the compose for repotting plants. If you separate a portion of the compost from the main pile the BSF will soon cycle out of it assuming you don’t add more food scraps to it. The BSF grubs are there for one reason, food. If the compost is in an open container the grubs will simply leave after any remaining food is consumed. If you want to have more control in removing the grubs from the compost you can use food scraps as bait and capture them using the method I describe here.

You also have the option of repotting any outdoor plants without removing the BSF. As I stated above they will simply leave when there is a shortage of food scraps. You might damage some of the grubs by handling them that way, but that’s the only downside I see.

The following post might be helpful if you haven’t already read it: http://blacksoldierflyblog.com/2008/09/15/mythbusting-black-soldier-flies/

Whatever you do please don’t throw out your compost, the BSF are harmless and the compost will have only been improved by their work.

Please let me know if you need further advice.

7) Difficulty establishing BSF in Michigan

I wonder if I should give up hope on this lot.  The larvae hatched last week into flies.  I’m hopeful that they left me some eggs.  But we’ve come into cold-for-July weather (again) and that might be the end.  The only action I see in the food pit area are fruit flies.  Not even regular house flies are around.  If the new BSF did lay eggs, how long will it take for them to hatch?  They had 2-3 days in the 90′s and now for the past 4 days it’s barely hit 70.

When you say the larvae hatched into flies are you referring to the mature larvae that were included in the kit? It’s good that you had adult BSF emerging, but what happened with the eggs from the kit? Did you ever observe the newly hatched larvae either in the ziplock bag or in your BioPod?

Can you describe the contents of your BioPod currently? (how much material, what type, species present)

Have you removed any food waste at all from the unit?

Given your cool temps it might be best for you to relocate the BioPod to a spot that gets some sunshine. The standard advice is to keep the unit in total shade, but the real goal is to have the internal temperature in the 80º-95º range. Actually your climate is great for operating a large BSF colony once you get it established. BSF generate quite a bit of heat when they metabolize food and in hotter climates it’s common that the colony will overheat. A good plan might be to keep the BioPod in at least partial sun for now and then to move it back to full shade when the colony starts growing.

8.) What to feed to a BSF colony

Hello Bonnie & Jerry

While I am waiting for the arrival of my BioPod, I am saving food waste and freezing it. My question to you is what food waste should be avoided if any? I could not find this info on your website. I have been processing food waste with the use of vermicomposting. This method as you may know restricts the use of meats, dairy and oils. If this info is on your website please direct me there, I may have
just overlooked it.

Thanks for your help!

It’s funny to think that we haven’t stressed what BSF (Hermetia illucens) can eat and it’s probably because the list is so long. BSF grubs can eat practically anything except high cellulose items like grasses, leaves, paper, etc. They can eat literally anything that people eat. In addition they do very well on manure from just about any animal. Fish bones and possibly chicken bones may be eaten eventually, but mammal bones will not. I’m pretty sure they can’t break down eggshells. This versatility of BSF is usually most appreciated by those who are used to the limitations of vermiculture and traditional composting. BSF happily eat meats, dairy, oils, onions, and citrus. They also seem to love old coffee grounds and teabags for some reason. I’ve also given them jellybeans and chocolate candy. :)

BSF can eat food that is quite spoiled, but it’s best to avoid anything that you think might contain toxins or high concentrations of pathogens, especially if you’re feeding the mature grubs to animals. The toxins/pathogens won’t hurt the grubs, but there is a risk of passing some to pets or livestock that eat the grubs. BSF have been proven to reduce bacteria like e. coli and salmonella, but it’s always best to err on the side of safety. If you have any doubts just limit yourself to “fresher” waste.

9) Limitations of feeding manure-raised BSF grubs to animals

I am confused about feeding animals waste to the BSF grubs . THe biopod site says NOT to use pet waste and then feed the grubs to other animals. But everysite I see , including the research done by NCSTATE uses them for just that purpose. Using BSF to process poulty waste and then feed the grubs back to the chickens. I raise rabbits and want to process the pellets( poop) with the BSFgrubs and then feed the prepupea to my chickens? Are they concerned about cats and dogs only? I hope some one can help my confucion.
THanks

The reason ProtaCulture says not to process pet waste is because of liability issues. Handling feces is more risky than handling kitchen scraps and in our society lawsuits are very common.

When feeding manure-raised BSF grubs to animals there is a basic rule that Robert from ProtaCulture (BioPod company) has given. BSF raised on manure from one type of animal (mammal, reptile, fowl, fish, etc) should not be feed back to that same type of animal. Accordingly you should be fine feeding BSF raised on rabbit manure to your chickens.

The information above is based on feeding live or unprocessed BSF to animals. I believe that if you process the BSF sufficiently, as was probably done in the studies you cited, it’s acceptable to feed them back to the same animals that produced the manure that fed the BSF. The issue is most likely about pathogens like parasites, bacteria and viruses, so by sterilizing the BSF the risk is eliminated and they may be feed to the same animals that helped produce them.

I’m not a biologist so please don’t take my comments as fact. (Yes, that was a disclaimer ;) )

10) Trouble shifting BSF from compost pile to BioPod

I’d really like to order a multistage starter kit, but didnt see where I could from your webpage. Please contact me with the information you’d need if one’s available, or to let me know when one would be available. I’m having lots of trouble getting the BSF population to shift over from ovipositing in my compost and the local Blow Fly population is all that’s taking advantage of my Biopod.
Help!

We don’t have an automated way to buy kits because the availability isn’t consistent. Bonnie will send you a bill if you decide you want one, and then I’ll begin the collection process.

In my opinion you really don’t need a starter kit because you have BSF on your property already and redirecting them won’t be difficult. To seed your BioPod you can cut 1/2 to 1 inch strips of corrugated cardboard against the “grain” so that the voids are exposed on the long side. Add some new food scraps to your compost pile and place the cardboard close to the scraps. A few inches above the waste would be an ideal location for the cardboard. When you see clusters of pale colored eggs in the cardboard simply move the cardboard to your BioPod. If the strips of cardboard are 8 inches or longer you can weave them into the large vent holes on the BioPod lid. This is simple if you invert the lid to access it from the underside. BSF eggs take about 4 days to hatch and they will then drop onto the food scraps.

Actively feeding juvenile BSF grubs are a strong attractant to ovipositing BSF so it would also be good to move some to your BioPod manually. Below is a link that describes how I collect juvenile grubs from my BioPod. This isn’t usually as effective in a compost pile, but you should have some success.

http://blacksoldierflyblog.com/2008/07/25/collecting-immature-larvae/

Since the BSF in a compost pile are less concentrated than in a BioPod you will have better success if you use a container with a larger diameter. The bottom of a 5 gallon bucket comes to mind, or even larger. Coffee grounds and a paste made from cheap dry dog or cat food are good bait. Almost any table scraps will work so you can just experiment.

Not much of a salesman am I? I think the kit is a neat project and you might want one just for the fun of it. The eggs come in a small container that allows you to see the tiny grubs concentrated in one area, something that you probably won’t see otherwise. I don’t have too many kits waiting now so if you want one I should be able to ship it in a few days. That is if the BSF and weather cooperate. :)

Thanks for your interest,
Jerry

11) Protecting BSF grubs while establishing a colony

Spectacular crawl-off last night!  Almost 300 mature larvae! I painstakingly cleaned and counted them so my kids could re-enact your “fist full of maggots” video.  Half of them I sprinkled strategically in the yard, the other half went in the pupation bucket.

I recommend against placing any grubs in the yard or anywhere outside of a protected environment. There is a long list of critters that love to eat BSF in any form including raccoons, possums, rodents, birds, lizards, frogs and other insects like ants. For many of these predators it doesn’t matter that the grubs can bury themselves because they can be located by scent. Each pair of BSF that are eaten represents a lost potential of 500-900 eggs that might have been deposited in your BioPod. This isn’t an issue with an established breeding colony, but it’s a significant issue when you’re trying to establish one. Of course if your property is treated with any type of insecticide that’s another reason not to release the larvae.

It’s best to keep the mature grubs in a container such as a bucket with a lid to protect them. The container needs to have several holes with a diameter of at least 1/2 inch to allow the emerging adults a way to escape. The holes will also provide necessary air for the pupating BSF and also aid in keeping the temperature regulated. Like the BioPod, the prepupae container must be completely shaded and protected from rain. Adding an inch of bedding material such as sawdust (not pressure treated), peat, etc to the container will encourage the grubs to pupate, but it must stay dry and loose so the emerging adults can crawl to the surface.

12) What to do with harvested grubs if you don’t have animals to feed

Hi- I am very intrigued by the idea of composting with
black soldier flies, but am not sure what to do with the harvested
larvae? I am a home gardener, so the compost & tea would go right
into my garden, but I don’t have chickens, or fish, or anything I can
think of that would dispose of the larvae. Any ideas? thanks!!

When I first began culturing BSF I didn’t have fish or anything else to feed the grubs to either. I simply released them. It’s true that you’ll be reinforcing the population by protecting the larvae though their most vulnerable stage, but I don’t see that as a problem. I believe that the BSF population is self regulating based on the available food, so I highly doubt that releasing mature grubs (larvae) would lead to an overabundance of BSF. I’ve probably released as many as 100,000 mature BSF grubs on my property over the past few years and it’s still unusual to see an adult. A wide variety of animals prey on BSF larvae including ants, rodents and other small mammals, lizards, amphibians, and many birds. By releasing mature BSF around your property you’re essentially feeding the many types of wild creatures around you. Of course if you have any friends with chickens, fish, lizards, etc., you’ll become even more popular if you have free high quality feed to offer them. :)

13) Containing BSF that are migrating out of a worm bin

We have plenty of BSF’s in our worm bin. I don’t mind them,
of course, except… they wander. They find ways to get out and I
find them wandering all over my garage where we keep the bin. Any
ideas about how to contain them?

The easiest way is to set the bin in a larger container or tray to catch the BSF as they migrate out of it. The grubs can’t scale a vertical surface if it’s dry so even something with a two or three inch wall will probably do the trick. Adding a thin layer of sawdust will ensure the grubs that fall into the catch-tray will be too dry to climb out.

14) Starting in a non-native area, concerned about BSF pestering neighbors

Hi Jerry!
I saw your link and subsdequent posts on Backyardchickens.com.  I have a few questions regarding composting with BSF larva.  How often do I need to buy/replace the larva (they are not native to the area) or will the flies stick around long enough to breed?  Also, the flies…they worry me.  I live on a half acre in a subdivision.  Our properties are big enough to not be in each other’s hair, but will the flies be a nuisance?  My biggest worry is that a neighbor will complain and attribute it to my chickens.  How do I control the fly population and nuisance while being able to compost with the larva?  Thanks so much for your time!

Hi,

Are you sure BSF are not native? I live in south Georgia where BSF are plentiful and most people here are completely unaware that they exist. Many people like farmers/gardeners are familiar with the larvae, but they don’t know what the adult even looks like. This is because the adult BSF is shy and only lives a few days. BSF are found in northern Viriginia, into central Illinois, throughout the south and up the west coast into Canada.

If there are no BSF in your area you’ll need some larvae and/or eggs to get started in late spring/early summer. During the summer you should be able to establish your own micro population which will replenish you colony until it gets too cool in the fall. The following page from my blog might be helpful: http://blacksoldierflyblog.com/the_biopod/bsf-multi-stage-starter-kit/

Concerning the flies; as you can see from my comment about BSF in my area most of your neighbors would never even see one of them. If they did see one they wouldn’t be pestered by it because BSF don’t behave like houseflies. BSF rarely land on a person or enter a home. During their short (5-8 day) lifespan the adults are entirely concerned with finding a mate and reproducing. The adult BSF don’t even eat in that stage and survive on stored fat. The good news is that the BSF population would probably lower the number of houseflies and other pest fly species on your property. If you culture BSF in a BioPod or DIY unit they will also show up in any available (open) chicken manure. When BSF inhabit a food source they tend to dominate it and as a result they limit or in some cases eliminate other fly species from breeding in that waste. Besides simply dominating the waste with numbers of individuals, BSF are also thought to emit an info-chemical that repels other fly species. I’ve raised and released hundreds of thousands of BSF adults on my property over the past few years and I still only see the occasional fly.

15) Can I automatically harvest BSF larvae from a worm tower?

Hello, I am new to composting and decided to try a worm tower. I follow the redwormcomposting.com blog and ordered 5 lbs of red worms from Mr. Christie. A couple of weeks after getting started, I found these larvae in my bin. Now, 4 weeks later, I have lots of  larvae but very few worms. The worms I have found are babies. Can the BSF and the red worms co-habbitate? I also quit feeding the bin for a while when the larvae were initially discovered because I thought they were bad. LOL, I know better now. Another question, can you give me a recomendation for how to set up a tube to harvest these out of my worm tower? Right now, I have lots of black ones at the bottom of the bin. I have seen one adult fly in the bin as well. Thank you for your help, Tracy

Hi Tracy,

BSF and worms won’t harm each other, but they each thrive in different conditions. For example, BSF generate a lot of heat and do fine at 100º. Worms do thrive in BSF castings and some people are working on culturing the two species in the same container, but I don’t think combining them will benefit both. Ideally I think you would process “fresh” food scraps with BSF and use their castings as a medium for worms. The problem as you know is keeping the BSF out of the worm bin. One way to do that is to avoid adding food scraps to the worm bin, but that kind of defeats the purpose I suppose.

I don’t know much about worms but I wonder if the lack of food might have been an issue. With BSF present any food would have been consumed quickly by them. If you have enough BSF it might have been an issue related to excess heat.

The black larvae are mature and the next stage looks similar but doesn’t move. This next stage is a pupa and after a few weeks an adult BSF emerges as you’ve witnessed. The bin isn’t a good environment for BSF pupation, but if they can’t escape the BSF will pupate there. As for harvesting the mature larvae I can only direct you to the DIY bucket composter on my site for details on the tube/ramp system. I’m not sure if you can adapt your worm tower this way but there is another method you can try. It’s easier to collect the BSF larvae before they mature because you can attract them with food (mature larvae don’t eat). I describe that method on the following page: http://blacksoldierflyblog.com/2008/07/25/collecting-immature-larvae/

If you can keep the worm bin in a shed or garage where BSF females can’t access it the existing BSF will eventually complete their cycle and you won’t get more. You would need to remove any BSF adults that emerge from the bin. The key is to keep BSF females from landing on the outside of the worm bin. BSF will lay eggs on the outside of the bin and the tiny larvae will enter after hatching.

I hope that helps.

16.) Not seeing the reported repellent effect toward pest fly species

I have seen several times your comments that the BSFL actually repel houseflies.  For me that is not true.  I have a lid on my bin and as soon as I open it up, out comes a swarm of houseflies.  It is as bad as food being left out in a garbage can.  Also, I have seen houseflies literally walking on a larvae in the bin.  Do you have any thoughts on why I might be having houseflies and yet still have a large thriving BSFL colony?

The only thing I can think of is that you don’t have sufficient density of BSF larvae to see the repellent effect. I’ve processed substantial amounts of fresh fish with BSF during an entire summer of 90-100º days with hardly a house fly around the unit. Keep in mind that this isn’t just my experience; there are several studies that record this effect. You can, however, nullify the repellent effect if you have an excess of uneaten and spoiling food waste in your unit. In other words; at some point the attractive nature of excess waste trumps the repellent effect of the BSF.

To see the repellent effect I would estimate that you need the equivalent of an inch or two of solid larvae in the container. I often will have more than that. Also, on average the waste should be consumed within about one day with soft items disappearing in hours and hard items like raw potato taking several. If you’re seeing the same waste sitting on the surface for days on end I’m not surprised that you would attract other fly species.

In the first photo below you can see two BSF laying eggs and also two house flies checking out some fish that I had added only two hours before. The house flies landed on the edge of the BioPod but not on the fish. One thing that probably helps the repellent chemicals produced by the BSF is the fact that you couldn’t smell the fish while standing next to the unit.

The second photo is two hours later; a total of four hours after I added the fish and no other species were present. The next morning there was nothing left of the fish except for bones, and still no house flies were seen in the unit.

BioPod colony 7-2-2009 1pm BioPod colony 7-2-2009 3pm

Comments 41

  1. Sam wrote:

    Hi Thanks for the great site!

    I am interested to know about how long the growing season for BSF would be in the UK ( Zone 8 )

    I will be growing them for chicken feed and I am considering building the pod adjacent to the chicken house so as to capture the heat from the chickens at night.

    Will an extra couple of degrees do much to extend the season?

    I also read where you wrote

    “There have been several attempts to breed BSF indoors and to my knowledge no one has succeeded. BSF require natural sunlight to mate, and the length of the day is important. Simply giving them a warm environment with natural light hasn’t led to successful indoor breeding in the winter months. I did hear a rumor that someone had found a type of artificial light that the BSF accept, but so far there’s no documentation of it.”
    http://www.redwormcomposting.com/the-share-board/vermimans-diy-bsfl-bin/

    Have you heard any more about this since January? Do you remember the name of the project?

    Thanks

    Sam

    Posted 19 Sep 2009 at 7:46 am
  2. Jerry wrote:

    Hi Sam,

    Yes, some advances have been made with indoor BSF breeding. My friends at BioSystems Design in Bogata, Columbia have seen BSF eggs hatch which were laid in their greenhouse. I don’t know anything about their BSF facility, but I think it’s safe to say that indoor cultivation is still a highly specialized endeavor.

    http://biosystemsblog.com/2009/03/27/eggs-hatch-complete-reproduction-cycle-of-hermetia-illucens-achieved-in-captivity/

    Keeping your BSF unit warm will effect the juvenile larvae which comprise the actively feeding colony, but mating happens outdoors and cool weather ends that part of the reproduction cycle. With proper insulation you can keep the juvenile larvae active and feeding through several months of cold weather, but the number of individual larvae will not increase. Therefore if you continue to use the larvae as chicken feed you’ll deplete the colony and need to restart it in the summer. That’s fine if you only want the BSF for feed, but if you wish to process waste through the winter you need to preserve the larvae.

    I’ve started a thread at the BioPod forum about winter operation of a BSF unit which you’ll find here: http://thebiopod.com/forum/index.php?topic=145.0

    Posted 19 Sep 2009 at 9:09 am
  3. Elliott Faure wrote:

    Is it possible to keep this system year round or is it only for the breeding period of the BSF?
    I am interested in the composting side of BSF and how I would restart/begin the cycle over again? Very interesting.

    Posted 27 Sep 2009 at 8:41 am
  4. Jerry wrote:

    Hi Elliott,

    You can certainly keep a BSF colony working year round. I’ve started a topic about winter operation at the BioPod forum: http://thebiopod.com/forum/index.php?topic=145.0

    If you stop using BSF in the winter restarting is usually pretty simple, especially if they are common in your area. After culturing BSF during the summer you will have seeded the property with even more BSF than might be there naturally. Even if you feed all collected BSF to animals some will always escape and become adults. Even so it’s recommended that you allow something like 10% of the larvae to mature, pupate, emerge as adults and then mate. Every pair of BSF that completes mating represents a possible 500-900 eggs to repopulate your colony.

    Posted 27 Sep 2009 at 10:51 am
  5. Brian Travis wrote:

    Hi Jerry, I am cross-posting this here and on the BioPod Forum.

    My “pudding level” in my BioPod stayed consistant until the past few weeks. Basically, the grubs ate everyting I fed them. But I noticed an EXPLOSION in grub density a few weeks ago – coincident with a prounounced fall off in mature grub migration. Along with an explosion in grub density, the level in the BioPod rose appreciably – even though I have only slightly increased the feed rate. I believe the grubs themselves are several inches thick now – thus adding to the level of stuff in the BioPod. I am in a quandry about what to do. Few mature grubs are migrating, yet DOZENS of mature BSF are hatching every day from my “incubator bucket”. Egglaying seems to be continuing and the population is full of HUGE white larvae (no longer self-harvesting), several different mid-sized populations of larvae, and literally MILLIONS of tiny baby larvae less than a millimeter in length! The corrugated discs are still full of eggs!

    The pudding is dry, fluffy and teeming with mixed sized grubs. I know I need to reduce the level in my biopod as it is nearly up to the top of the ramp. But I am afraid of losing an appreciable number of immature grubs if I do so. I’ve considered removing 5 to 7 gallons of pudding/grubs, setting them aside, then digging out the bottom layers of the BioPod pudding, setting it aside, restocking the pod with the grubs and pudding taken off the top, then using your methods of harvesting remaining immature grubs from the bottom half of stuff. I hate to do this with cooler weather here just a month or so away, but I gotta do something to reduce the level. I want a robust population for December thru February when the weather will warm up again here in southwest Florida, so I am open to suggestions for techniques to harvest the pudding, yet maintain my population.

    Anyone here have ideas or suggestions? I could easily populate a second or even third BioPod with my current population!

    Posted 23 Oct 2009 at 3:53 pm
  6. Jerry wrote:

    Tarvus, I’m not sure what I would do in your situation. Your plan for removing the bottom material sounds reasonable to me. I wouldn’t worry about losing a portion of your BSF larvae because you clearly have a healthy wild population that will still have time to lay more eggs before the end of the season. You always have the option of waiting to remove the compost until we’re into winter, that way you wouldn’t have to deal with small grubs.

    It sounds to me like you have a very health, well balanced colony going. :)

    Posted 23 Oct 2009 at 6:47 pm
  7. Brian Travis wrote:

    “It sounds to me like you have a very health, well balanced colony going.”

    I think you are right about that, Jerry! The past week I’ve been feeding the BioPod a minimum of 20 ounces of coffee grounds each day, 2 to 3 pounds of fish/fish offal, dog and cat feces from 3 dogs and 3 cats, plus kitchen scraps! In 12 hours, it’s all gone! MILLIONS of grubs have populated the BioPod! There is no smell – even with the feces and fish added daily! No houseflies dare approach the BioPod anymore either!

    There are only maybe 6 or 8 mature grubs self harvesting each day. I think the big grubs are hanging out waiting for winter because the largest grubs in the bin are half again as big as the mature, self-harvesting ones! Unfortunately, the level in the Biopod is such that half the harvesting bucket is full every morning with immature grubs. I pick out the dark ones to add to the hatchery bucket and put the rest back in the BioPod. It’s just so full they fall through accidentally now! There is no longer any moisture problem in the bin either. In fact, I periodically add water when things start looking too dry.

    Up until the cold snap last week, I was seeing 2-3 dozen adult flies every morning when I checked the hatchery bucket. Now that’s dropped to 6-8 each morning.

    I still see an occasional adult laying eggs, but I think the egglaying rate is slowing too with the change in season.

    I’m off tomorrow and plan to spend several hours reducing the pudding level in the BioPod. When the immature grubs achieve the size of the large grubs, it’s got to add several more inches to the level of the BioPod – just from the volumetric increase in the size of the grubs!

    I am totally blown away by the surge in population in the past few weeks AND with the voracious appetite of those grubs! I truly believe I could double my feeding rate at this point without adverse effect! The problem now is I no longer have the space to do so until I lower the “pudding” level!

    I’m going to order some eisenia foetida worms online to process the surplus pudding this winter. I’m also going to stop populating the hatchery bucket with pre-pupal larvae. I think we have a sufficiency of wild BSF here!

    I’ll try and post photos soon!

    Posted 25 Oct 2009 at 7:26 pm
  8. Jerry wrote:

    Excellent Brian.

    I think you’re seeing juvenile crawl-off because of overheating due to the density of your colony. I use three pieces of 1 X 4 lumber as shims to allow more ventilation:

    Posted 25 Oct 2009 at 8:29 pm
  9. Brian Travis wrote:

    That might well be the case, Jerry. I’ll try adding some shims for additional ventilation.

    I’m including a video I uploaded to photobucket. I shot the video shortly after 9PM tonight. The fish visible in the video was a 1.25 pound ladyfish that I kept – intending to use as redfish bait, but didn’t get a chance to go back out fishing. I added it to the BioPod at about 10:30 this morning. The video was filmed while I was wearing a headlamp and holding my camera in the dark, so please excuse the herky-jerky filming. You can see a range of grub sizes from under pinhead size to a good inch in length. It seems the bigger grubs lurk deeper in the pudding and the small to mid sized ones crawl up to devour the fresh food. The young, mid-sized grubs remind me of what it was like having teenaged boys living at home! I think the larger grubs have slowed their consumption and are just chillin’ and maintaining their weight until spring. There are WAY more large grubs in the BioPod than show up in this video. Seems like the smaller ones wanted to star in this one!

    Posted 25 Oct 2009 at 8:46 pm
  10. Wan Muhammad Afiq wrote:

    how I can attract BSF at Kuala Lumpur,Malaysia??

    How to know BSF larvae and house fly larvae??

    Posted 29 Nov 2009 at 10:42 am
  11. Elliott Faure wrote:

    Odor/Smell. Please explain the odor situation. If it is true that this unit must be outside, how offensive is it? Will my neighbors nose be offended and complain? If I walk by it, will I get a whiff reminding me wants in it? This is extremely important because I am interested in this unit handling and processing human feces. H.F. composting piles aren’t in any shape or form offensive if properly maintain and balanced. And under all the leaves and organic matter no one has a clue as to what is really there. Is this possible in the Biopod with BSF? Can I be guaranteed this compared to what a composting pile can handle and offer. I am impressed at BSF’s speed of composting and the immediate ability to handle “HOT” material which vermicomposting can’t until the heat phase has passed. Thanks.

    Posted 20 Jan 2010 at 3:56 pm
  12. Jerry wrote:

    Elliot,

    The short answer is that a properly balanced BSF colony has a very faint and even pleasant odor reminiscent of wet straw and whatever waste you’re processing. For example if you process strawberries or cinnamon bread in a healthy BSF unit it will smell very good. On the other hand if you process feces (caution advised) then it won’t smell so good depending on the type. Even when processing bad smelling waste I doubt that it would be strong enough for neighbors to notice unless they’re fairly close to the unit. I’ve processed a lot of whole fish and trimmings during very hot weather and my dense and balanced BSF colony processed it so efficiently that you could stand nest to the BioPod and not smell anything or even see a housefly.

    I’ve never processed human feces but I have added dog feces to my colony. The effect was a noticeable odor but one that wasn’t much stronger than the fresh feces itself. One thing that I think would effect this is the churning action of the BSF which might serve to keep releasing the odor. Another factor that might lessen the odor is the speed at which the waste would be processed which as you noted is very fast. I hope more people will experiment with this and add to our knowledge.

    Thanks.

    Posted 04 Feb 2010 at 11:26 am
  13. NS wrote:

    Hey, great site!

    I have two questions I’m hoping you could answer:

    1. I’m guessing there are natural BSF populations in northern California. Would you also think so, based on climate?

    2. Assuming you kept the temperatures around, say, 50 degrees year round, could you keep the grub production pretty constant (without a winter slow down)?

    thanks for your time.

    Posted 20 Apr 2010 at 5:17 pm
  14. Jerry wrote:

    NS,

    I’ve communicated with several people that report BSF in northern CA.

    At 50º the larvae will be dormant and there will no reproduction. For mating you would need a heated space about 10 X 10 X 10 feet (3 meters) with a lot of light, preferably natural. and probably at least 70º but ideally more like 85º. I don’t have experience with that type of BSF operation but what I outlined is a quick checklist of what I’ve read. There is always room for exceptions. It is possible to process waste with BSF larvae with ambient temperatures at freezing and even below if you insulate the unit and keep food available at all times. The key point being that the internal temperature of the colony needs to stay in the 80′s and since BSF generate heat when they eat you only need to conserve that heat. In cold weather the larvae that usually mature in a few weeks will remain in the juvenile stage for 5 months or more, eating for the whole period. There will be very few larvae maturing and harvesting the juveniles isn’t recommended because they won’t be replaced until mating resumes in the spring.

    Posted 20 Apr 2010 at 10:18 pm
  15. Brett wrote:

    I’m just looking into BSF vermiculture. We have 6 hens that would love to have some of the grubs once in a while, but I have a question about the liquid drained form the system.

    I saw a comment that it might not be wise to use it on a vegetable garden as a tea. Do you know where I might find more information about the pros/cons of doing that?

    Posted 27 Apr 2010 at 2:35 pm
  16. Jerry wrote:

    Hi Brett,

    I haven’t studied the liquid effluent and I don’t use it. I’ve read mixed reviews about its effectiveness as fertilizer. I’m sorry but I haven’t found any in-depth studies about it.

    Posted 28 Apr 2010 at 6:49 am
  17. (Mr.) Bari Dailey wrote:

    We had our first experience with Black Soldier Flies last year in our compost bin (called an ‘Earthcomposter’ or something like that – we bought it from Costco Wholesalers). Loved every one of those critters when we found out how beneficial they are. Fed the bluebirds some of the larvae before the baby bluebirds fledged. then used the ‘castings’ in our raised vegetable beds at the end of the season.
    My question. We are now at the end of April and I am wondering when our beloved Black Soldier Flies will appear. Any idea. We live in the Atlanta area of Georgia. I keep fresh compost vegetation in the composter but see no activity to date except for some gnats. I have a little dirt and leaves (not much) mixed in with the vegetation – will that discourage the flies? I appreciated this blog. Very helpful. Thank you kindly.

    Posted 30 Apr 2010 at 9:37 pm
  18. Jerry wrote:

    Hi Bari,

    I live in Georgia also, just a few minutes from the Florida line. I saw my first BSF of the season on April 12th so you can expect to see them shortly. I doubt that the leaves and dirt will matter to the BSF as long as you have fruit, vegetables, and grain products available. I’m glad you discovered BSF and I hope you enjoy the coming season. I’m glad you like my blog, thank you.

    Posted 30 Apr 2010 at 10:03 pm
  19. Christian James wrote:

    Hey Jerry,
    Have you had luck collecting the eggs? I’ve got both a biopod and an in-ground compost pile (used for grass clippings, jackfruit & other large items) – and of course I get way more BSF egg clusters in the compost pile. I cover the compost pile w old tin roofing that the adult BSFs love to lay their eggs under. Have you had any luck scraping the egg clusters off? I would love to take them off and add them into the BioPod, but want to make sure I’m not going to kill them in the process. Also once moved is there a specific way that works best to add them into the Pod? – I’m guessing not directly on the food, but maybe on a piece of wood or similar?
    thanks!
    -Chris

    Posted 03 May 2010 at 6:04 pm
  20. Jerry wrote:

    Hi Chris,

    Yes I collect eggs quite a bit, mostly from the black plastic garbage can liners I use. I keep one can until the garbage starts to smell a bit and the BSF come and lay in the folds of the liner. Often a dense cluster will fall away easily and I catch it in a small dish. Otherwise I stretch the bag over my thumb and gently scrape the eggs away with a knife held perpendicular. I’m sure a few eggs do get damaged.

    As far as putting the eggs in you BioPod; I haven’t figured out a good method for that. Mostly what I do is hatch them in a small container and then add the larvae by rinsing them in. You can take any small dish with a very small amount of moist bread or other cereal product and place it in a zip lock bag. The bread should provide enough moisture and there is often condensation on the bag. When they start hatching you can see their trails in the condensate. They will work their way to the food and start to grow. Even when they’re still tiny you can flood the cup and pour them directly into the BioPod.

    You might try putting strips of corrugated cardboard under the tin roofing. Look at the voids in the cardboard for the BSF eggs and when you get some you can simply add the strip to the BioPod. It should just “float” on top of the waste until the eggs hatch and the cardboard will eventually be shredded by the larvae or you can remove it.

    Posted 03 May 2010 at 7:46 pm
  21. Christian James wrote:

    Thanks Jerry!

    I ended up taking a plastic container, cutting the bottom off, and hot gluing some fine screening material to the bottom. I then added some wood chips into it and the eggs on top. I’ll put this on a side of the BioPod and the babies can travel down to the food once they hatch while remaining dry in the process.

    On another note, I’ve also found that placing a solid piece of plastic, wood, or metal right on top of the food and grubs seems to be very beneficial to a starting colony. They congregate under the center of it, and maintain a soup-like consistency – whereas without it my medium was drying out and I’m sure the efficiency was much lower. This probably isn’t necessary once the colony is fully established, but until then it’s something to think about.
    -Chris

    Posted 04 May 2010 at 3:54 pm
  22. Jerry wrote:

    Chris, your hatchery sounds like it will work fine. One thing to consider; once you put it in the BioPod you should assume that BSF have laid eggs on it. That’s my issue with putting devices in a unit; I never want to remove them for fear of wasting eggs. It sounds like you could just leave it in place until your colony gets large and at that point a few eggs won’t make a big difference.

    I like the idea of keeping something on top of the waste. BSF need at least 70% humidity and the newly hatched larvae are especially at risk of dehydration.

    Thanks for sharing your ideas.

    Posted 04 May 2010 at 7:08 pm
  23. kwatts wrote:

    Hi Everyone.
    Could someone please tell me how I can add all the bsfl residue to my worm bin without overpopulating my bin with larvae?

    Posted 30 May 2010 at 7:17 pm
  24. Jerry wrote:

    Hi kwatts,

    The population of BSF larvae will only increase if eggs are introduced, usually by a female BSF depositing eggs on the inside or outside of the bin. If laid on the outside the eggs hatch and the tiny larvae find their way inside. Be aware that once you add larvae or their residue to the bin it will most likely attract egg laden female BSF whether you want more larvae or not. Each female will deposit about 500 eggs.

    Posted 30 May 2010 at 7:36 pm
  25. erik wrote:

    question: any research or ideas for developing countries to use black soldier flies for toilets?
    Other question: How long did it take to make the 5 gallon bucket harvester? I am enjoying black soldier flies and all that they do!

    Posted 12 Jun 2010 at 1:16 pm
  26. Jerry wrote:

    Hi erik,

    I believe Dr. Olivier has introduced the idea in Brazil and Vietnam but I can’t direct you to any specific info. BSF larvae were traditional inhabitants of outdoor toilets when they were common. This had the benefit of reducing the volume of waste and also of repelling disease carrying species. An old common name for BSF related to this behavior was “privy fly”.

    The first bucket I made took about an hour to make but I’m getting quicker as I learn the process.

    Posted 12 Jun 2010 at 1:27 pm
  27. Lee wrote:

    I have seen several times your comments that the BSFL actually repel houseflies. For me that is not true. I have a lid on my bin and as soon as I open it up, out comes a swarm of houseflies. It is as bad as food being left out in a garbage can. Also, I have seen houseflies litterlly walking on a larve in the bin. Do you have any thoughts on why I might be having houseflies and yet still have a large thriving BSFL colony?

    Posted 16 Jun 2010 at 6:00 pm
  28. Jerry wrote:

    Hi Lee,

    The only thing I can think of is that you don’t have sufficient density of BSF larvae to see the repellent effect. I’ve processed substantial amounts of fresh fish with BSF during an entire summer of 90-100º days with hardly a house fly around the unit. Keep in mind that this isn’t just my experience; there are several studies that record this effect. You can, however, nullify the repellent effect if you have an excess of uneaten and spoiling food waste in your unit. In other words; at some point the attractive nature of excess waste trumps the repellent effect of the BSF.

    To see the repellent effect I would estimate that you need the equivalent of an inch or two of solid larvae in the container. I often will have more than that. Also, on average the waste should be consumed within about one day with soft items disappearing in hours and hard items like raw potato taking several. If you’re seeing the same waste sitting on the surface for days on end I’m not surprised that you would attract other fly species.

    In the first photo below you can see two BSF laying eggs and also two house flies checking out some fish that I had added only two hours before. The house flies landed on the edge of the BioPod but not on the fish. One thing that probably helps the repellent chemicals produced by the BSF is the fact that you couldn’t smell the fish while standing next to the unit.

    The second photo is two hours later; a total of four hours after I added the fish and no other species were present. The next morning there was nothing left of the fish except for bones, and still no house flies were seen in the unit.

    Posted 16 Jun 2010 at 8:01 pm
  29. Ej wrote:

    I am thinking about selling my surplus to local fisherman (when I have surplus). I have read that there is a special substrate that will keep them from morphing into a fly. Do you know what that substrate would be? I was thinking of putting them in organic soil do you think that would work?

    Posted 22 Jun 2010 at 6:36 am
  30. Jerry wrote:

    Ej,

    The only way I know to keep the larvae from maturing is to keep them refrigerated. If you do that you must be sure to keep them moist (goal=70% humidity), and that you provide them with sufficient fresh air. For fish bait I would use damp sawdust as a bedding. Good luck!

    Posted 22 Jun 2010 at 2:58 pm
  31. Lee wrote:

    I had mentioned before that I don’t seem to have the repellant affect of other flies that is often talked about. Well, I am pretty sure now that I have house fly maggots. My colony seemed to take a population drop and now I think I recognize maggots from the housefly crawling around. Is this a problem for the BSFL or will they all just get along?

    Posted 02 Jul 2010 at 8:12 am
  32. Jerry wrote:

    Lee,

    I’m curious why you’re seeing this happen. It might be helpful if you could post a clear photo of your waste pile, preferably just after you’ve added fresh waste and the BSF larvae are working at the surface. To answer your question; no, the house fly larvae won’t effect the BSF, but this should be a temporary situation.

    Posted 02 Jul 2010 at 8:24 am
  33. Jenn wrote:

    I have a plastic tumble composter that I am constantly “hunting” through to move BSF larvae to the bucket composter I made following your directions. The problem is that no matter what I do, the flies prefer to lay eggs in the composter! I have even tried putting the bucket inside the tumble composter when I see the adults flying around. There are deep grooves on the inside walls of the composter, and this is where most of the eggs are being laid, I have tried cardboard, but they love those grooves. Because they are so deep and narrow, the only way I can find to get them out is with the tip of a sharp pencil. I put it underneath and lift them out the best I can. I just started, so I am not sure how it will go. The first clutch I found (I am guessing) was fresh because I was able to put the eggs on the inside of the bucket lid, and they stuck. Not so much luck with others. What do I do with them. Right now, they are in a plastic container that is leaning sideways on top of the scraps. Any suggestions or ideas?

    Posted 03 Jul 2010 at 3:27 pm
  34. Jerry wrote:

    Hi Jenn,

    The BSF prefer your tumble composter because it smells better to them than your BSF unit smells. All you need to do is reverse that situation. I would stop adding any kitchen scraps to the tumble composter and limit that type of waste to the BSF unit. You can add a few pounds of scraps to the unit immediately. This is more than I usually recommend in the beginning but since you have a good BSF population nearby already you’ll see the colony in your BSF unit grow quickly. Keep adding BSF eggs to your bucket composter. Your set up for the eggs sounds find and you might want to mist it lightly with water a few times a day. Keeping the egg container moist will help the newly hatching larvae crawl out and into the scraps. Without knowing how your tumble composter is built I wonder if you could insert strips of cardboard into the grooves that the BSF are targeting. If they’re too wide for a single strip you could double or triple them until they stay wedged in place. I would still try to encourage the BSF to stop laying in the tumble composter, but they will probably be attracted to it for a while anyway.

    It sounds like you’re doing well and I hope you’ll stay in touch.

    Posted 03 Jul 2010 at 4:05 pm
  35. Jerry wrote:

    Jenn,

    If you ferment some dried corn or fresh cabbage I think you could direct the BSF anywhere you want them. Check out one of my earlier recent posts for details.

    Posted 03 Jul 2010 at 4:49 pm
  36. nopi wrote:

    We have lots of coconut trees here in the Philippines and we love to eat food cooked with coconut milk. I am now at the third month of raising bsf and I am using grated coconut meat (minus the milk) as their food. I have experienced overfeeding them and have a problem with the offensive smell. I was able to lessen the smell by adding lacto baccili.

    Posted 04 Jul 2010 at 10:01 pm
  37. Kathleen wrote:

    Very informative blog you have going here – well done! I found you through doing research into fly larvae in my worm bin. Happily, it seems they are the BSF and not house or blow fly larvae! Thanks for all the info you’ve made available, I appreciate it.

    Posted 11 Jul 2010 at 3:07 pm
  38. Jenn wrote:

    Help!! My BSF population has begun to take off, and I now see constant adult activity around the bucket. Well, obviously, the increase in population caused an increase in feeding and waste. I have been making sure that they are able to eat the scraps within a day assuming this meant that I wasn’t overfeeding, and did realize that the waste had become thicker and more “sludge-like,” which I attributed to more grubs. However, what I did not notice was that, because it is so much thicker (I am guessing), things are not draining like they should-not sure how long this has been going on, but I am thinking several days. Anyhow, today I went to add scraps to the bucket and noticed it was VERY wet and not smelling great. (I also had about 10 adults flying out of the bucket, which thrilled me, until I realized why!) I moved the bucket to a new spot where I could tilt it to try and improve drainage from the tubing and began to try and mix in some shredded paper (cross cut) to absorb the moisture. The minute I disturbed the surface, the smell was overwhelming. I am talking about a stomach turning event! I turned in a large amount of paper (while holding my breath) along with a bit of dry bread. This morning I checked and the only difference is I can smell it from a distance now. I know that this means things are completely out of whack, but I am not sure what to do. Once I saw the population increase, I removed the golf ball that I mentioned in an earlier post. Things are barely draining. I think it is so thick in there that I have gummed everything up. In hindsight, I am guessing that I should have completely cleaned the bucket yesterday and strained the larvae to start fresh. The problem is that now that I added the bits of paper, I don’t think that will work! My daughter also saw some coffee and strawberries out last night, and out of habit tossed them in the bucket (more wet items-lucky me). I have TONS of eggs all over the bucket and velcro (this is the favorite place to lay eggs lately), and don’t want to rinse them away. What can I do? This is a truly horrible smell! If I don’t figure this out, my family may revolt-assuming the neighbors don’t first! I spent much of last night searching online. I saw a recommendation to add flour products, but think I may end up with paper mache at this point! I also clearly need to work out this drainage issue long term. I teach kindergarten and was so hoping to set something small up outside for my class to put some snack scraps in to teach the kids about BSF, but will have MAJOR problems with co-workers and parents if I repeat the issues I am having with my home system. Please tell me what to do-I have created a monster!

    Posted 21 Jul 2010 at 10:38 am
  39. Jerry wrote:

    Hi Jenn,

    Thanks for reporting this issue; this is how we can refine our equipement and techniques. Below I will list some general concepts you may or may not be aware of, as well as some new ideas inspired by your current situation:

    Don’t overfeed – The bucket composter is a relatively small BSF unit which can only process a few ounces of waste per day, maybe up to one pound (.5kg) if carefully managed. Rule of thumb; don’t add more waste than can be consumed in one or two days on average. The shape of a common bucket isn’t ideal for what we’re doing with it. I believe the key factor that determines the volume of waste a unit can handle is surface area and we don’t have much with this design. I should make it clear that this unit is not intended to be a workhorse, it’s more a tool for learning about BSF.

    Drainage drainage drainage – The unit must drain well. :) Just today I found that the system I’ve been using in version 2.1 for about a month is gradually failing. This wasn’t exactly a failure of the filter medium which is still in a condition to filter liquids; the problem is in the support system which, in this version is done with plastic golf balls. Due to the constant churning of the larvae the golf balls are mixing with the filter medium. I suspect this arrangement would still filter adaquately for a while, but at this point I’m going to test some type of disc to support the filter. I will probably continue to use the golf balls or some similar items to create the liquid collection area, but I will insert a porous disc on top of them. I may also use an additional disc on top of the filter medium to help minimize expansion.

    I think that we may not be able to rely solely on a filter material for adequate drainage; it may be necessary to monitor and adjust the content and consistency of the waste material itself. BSF larvae can’t eat wood shavings but I add them to my unit because I believe they work as a moisture buffer and they might also effect the texture of the waste in a way that improves drainage. It just now occurred to me that ground corn cob might be even more effective than wood shavings because of its sponge-like texture. Corn cob might facilitate better drainage and also result in better aeration of the waste. The need for, and quantity of cob or wood shavings will vary with each unit because the waste is different in each.

    Jenn, based on the above information I suggest that you:

    *Remove the waste from the unit and modify the drainage system. If you don’t get a clear picture from my description above for the filter send me an email and I’ll go into more detail. I hope to add a new description and photos for the modified design on the composter page today or tomorrow. I think we’re seeing the developement of version 2.2. :)

    *Mix corn cob bedding into the waste. I know you can buy it at pet stores, and I hope to find it cheaper, maybe through feed stores. I can’t tell you how much to use but you can start out conservatively and add more if needed. I would also add an inch or two (40mm) directly on top of the filter material before to return the waste to the unit.

    *You might consider adding only a portion of the waste back into the unit since it’s clearly anaerobic.

    *Stop or reduce the addition of new waste to the unit until the bad odor (anaerobic bacteria) is under control.

    It might have been nice if everything had gone perfectly with your attempt to use the current design, but I’m glad you took the time to report the problems since we both have an opportunity to learn from them.

    Thanks!

    Posted 22 Jul 2010 at 11:54 am
  40. Jenn wrote:

    Thanks for the tips. Stirring the paper in and tilting the bucket toward the drain side have made a huge improvement in the odor and wetness.

    I also have a vermicoposter, and when I had worms and BSF together, I had a huge increase in worm population. I truly think the BSF waste had much to do with it because the population has decreased quite a bit since I removed the BSF larvae. Since the moisture has decreased dramatically, I may try adding some redworms to the mix to see if that will help bring things under control before I pull everything out to modify the drainage. I am assuming that if I do not add new waste for a few days (the other has been consumed) that this will mean no new liquids. Is this correct? If you can’t tell, I am really trying to fix the smell and moisture as much as possible before digging in! Also, what is the best way to preserve any eggs before washing things out? I know the vast majority that were laid in the velcro (they have also managed to peel the edges up and lay it there) may be lost because I cannot move them without damaging them and they may be washed away. There are also lots under the outside rims of the bucket.

    I have been thinking some about how to improve the base of the filter system. I am toying with the idea of making some kind of legged frame (tripod or four legs) that will fit above the level of the drain and topping it with some kind of wire or plastic mesh (wider holes-similar to the plastic needlepoint mats from the craft store). I am also thinking about trying slide washers up the legs before placing them in the bucket with heavy monofilament or something similar tied to the washers that could run up and outside the top of the bucket. Maybe I could add washers to the outside ends and stick them to the magnets just to keep them attached, but out of the way? In the event that this happened again (or I just needed to change the filter material, I could just place the bucket in a larger container, and lift out the contents without having to “muck around” so much in the mess. If everything is fine, I could replace the filter, lower the leg stand in, place the filter on top, and pour everything back in. I am not sure if I did a great job explaining this, but can you kind of see what I am thinking? Any thoughts or suggestions?

    Posted 22 Jul 2010 at 2:28 pm
  41. Spiro wrote:

    Do you know where can I get this lill buggers in Europe. Because I dont think you package will get to me in Serbia.
    Best regards Spiro

    Posted 29 Jul 2010 at 4:10 pm

Post a Comment

Your email is never published nor shared. Required fields are marked *