Black soldier fly larvae + Earthworms = bio-composting²

[GW]

I recently learned that combining Vermicomposting and Black soldier fly larvae composting may represent the most potent technique for organic waste processing available. I have no experience with vermiculture but it's my intention to begin working with earthworms in the near future.

If you are experienced in vermicomposting and would consider testing a combination of the two techniques please reply in this thread. I've started a post concerning this at my blog and I'll update it when I get started culturing worms. If you have experience with both worms and BSFL your input will be especially appreciated.  

EDIT: The original idea of this thread was about using worms and BSF grubs to very efficiently process waste in two steps with each species in separate containers. BSF and worms have different requirements and tolerances which makes combining the two difficult. BSF grubs often show up in worm bins and I've never heard of them hurting the worms directly. BSF do generate a lot of heat which is problematic for most types of worms. The real issue isn't whether the two species can survive together, they can. The real issue is getting high levels of performance from both of them in a combined system. BSF perform best when the internal temperature of the colony is around 95ºF/35ºC and of course this is too hot for worms.

The appeal of working with both species has to do with 1) the speed at which BSF can consume relatively fresh waste 2) the fact that worms thrive in BSF castings. For this reason combining the two is a worthy goal. Ironically, if you try to keep worms and BSF separate on the same property you will probably find it challenging. To accomplish that you need to keep the worms somewhere that the egg laying adult BSF can't access. Perhaps you could discourage BSF from targeting a worm bin by limiting it to only those items which BSF don't consume, like paper and leaves. The question then becomes will the BSF castings alone attract female BSF and my guess is that it would. The difficulty in keeping worms/grubs separate is just more motivation for a combined system.

BSF and worms are each attractive for processing waste because they can do it with very low-tech systems. Therefore, for a combined system to be attractive it must also be low-tech. Honestly I'm very doubtful that there is a simple and effective solution to this puzzle, but at the least we can probably learn more about both of these fascinating creatures by trying.

[vermontworms]

Howdy Jerry, I've been doing vermicomposting for almost 5 years, and am just getting into BSF larvae (with the larvae you sent me!).  Looking forward to sharing info here.  You can read about my vermicomposting efforts at http://www.vermontworms.com/.

[GW]

Hi Jase.

I've been so busy with work and my blog/bsf colony that I haven't been thinking about vermiculture lately. Can you recommend a commercial worm bin for someone with little time for more projects?

[vermontworms]

Hey Jerry, missed your post.  I generally keep my worms in wooden bins I make from rough-cut hemlock (pine/spruce would be fine, but hemlock is more rot-resistant).  The wooden bins seem to control moister and breath better than plastic.  I've never tried a commercial bin.

[rolivier79]

The only concern I have had with using vermiculture AND black soldier fly is that the Black soldier fly give very little residue for Earth Worms to proliferate in. Black Soldier fly tend to be habitat or nich dominant. It would require a fairly complicated apparatus to host both species. Remember the Black soldier fly will dig down and try to establish themselves in a nearby wormbin.

Karl and I talked about this for some time and we thing we have come up with an interesting alternative.

In colder climates BSF Colonies will go dormant as winter approaches and it will become impossible to keep a BSF colony outdoors.

Instead of bringing the BSF colony indoors and coming up with an apparatus for the solier fly to mate under artificial conditions, simply start a worm colony in your garage in Fall. Since worms take a few weeks to establish themselves, the BioPod in your yard can keep handling most of your food waste for the time being. Eventually you let the colony go dormant and this is the ideal time to bring the biopod indoors and let the worm colony take over de decomposition process

When Spring comes around you empty the biopod 100%, there should be no more larvae in there and this is the perfect time for you to harvest the worm castings and apply them in your garden.

In this way Earth Worms compliment Black Soldier fly because they can operate indoors in colder winter conditions, and they provide valuable Earth Worm castings for your garden. However, I don't think there is a need to have both system running at the same time... transitioning from one system to the other in the same device should be more then enough. In worst case scenario you might have to get an extra worm bin, but i would try utilizing the biopod first.

[GW]

I like this idea because it avoids the problem of BSF females following the scent of the BSF castings and laying eggs in the worm bedding. Even if you bring some BSF larvae into the house in the BioPod you will be able to collect them as they mature.

[vermiman]

I've been raising worms for about a year and a half.  When I add cantaloupe rines on top of the bedding I find several black soldier fly larvae.  How do you build up the population of BSFL?

[GW]

Hi vermiman,

The main thing to do to increase your larvae numbers is to contain them. In a container that allows them to leave you will have regular migration out of the unit. In a BioPod or similar unit the larvae are contained, which has the added benefit of concentrating their scent. The scent of BSF larvae is a powerful attractant to BSF females searching for a place to lay eggs.

A dedicated BSF unit has other advantages which include ramps that result in the mature larvae self harvesting into a collection bucket. BSF often show up in compost  and worm bins which is great, but those types of containers don't provide the conditions for maximizing BSF culture.

Welcome to the forum!

[vermiman]

OK, so how does one have a home for worms and a home for BSFL all in one unit; maximizing both the BSFL and worm cultures?

[GW]

That's a good question. I've seen the idea mentioned but I haven't heard anyone claiming to have done it. I don't know much about vermiculture so I can't even suggest a direction at this time.

I'm not sure if it's even that important to maximize both cultures. If you could find a convenient way to house both species together while they each performed at 70 or 80% efficiency I think you would have an appealing system. In other words, if you have one container with worms and BSFL each working at 80% of their potentials you would have a powerful system overall.

I've been asked by several people about whether BSFL will eat grass clippings and paper. Of course the answer is no, and it would be great if someone designed a single unit capable of efficiently processing grass, paper and food waste. Do you have some extra time?

[vermiman]

I've just top fed the worm bed that once had BSFL a cut up pumpkin rind to see if the BSFs will come back.  The last time it had BSF visitors is when I fed a massive amount of cantaloupe rinds.

[delawaremike]

I've been vermicomposting for a year. I'm primarily using coffee grounds from a local store that can supply as much as 120 lb/day. I've been looking for other critters that will eat coffee grounds. Does anyone know whether soldier fly larvae will eat coffee grounds. I've seen online that they will eat coffee pulp. I just ordered some soldier fly larvae (200) to start.

Also, I'm getting the distinct impression that it's not a good idea to have red worms and soldier flies in the same area - I use my garage for this. Is that what I'm hearing? Thanks for your help. I'm glad I found this forum.

[GW]

Hey delawaremike. BSFL love coffee grounds. I've always been curious about it because I can't imagine there's much nutrition in it. I wonder if the caffeine helps their digestion or something. I can't imagine that you could maintain a BSF colony on only coffee.

I don't think there's any harm to earthworms when they share a space with BSF larvae. The biggest concern is most likely related to the convenience of managing each species. As I said before, I'm not experienced with worms so I'm only guessing.

I hope you keep us posted about your progress with the larvae.

[Sunnyslopes]

Hello GW,
I'm new to this group as well and have read some of the discussion. I have been raising red wigglers for about a year to use in the garden. Although I have not had a lot of luck getting the reds to reproduce they do a great job at turning cheep manure into a high quality soil amendment. I have not come to the conclusion that BSF is a win for the worms but can see the logic. By using composted cow manure CCM and a light feeding of grounds and corn meal I can keep the BSF from blooming in the worm bin. Or at least keep the population very low. Adding some composted chicken manure or just about any rich waste I will get a burst of BSF activity. Also the BSF do a great deal of good. I have recently added some quail in small cages and have established a nice colony of BSF larvae under the cages. The quail love the larvae as a treat. I just need a convenient way to harvest and will have a nice supplement for the quail. As I side note the BSF are not constent as sometimes I will go weeks without activity; then boom! The surface of the ground under the cages will be boiling with BSF larvae (BSFL).

[Sunnyslopes]

I forgot to mention that I had the same results with coffee grounds. BSF larvae love coffee grounds. It was a surprise to me to see so much activity.