Black Soldier Fly Larvae Notes

BSFL trial:
Last year, I started a black soldier fly trial to see if we could produce larvae for the Fish Food Project.

I made a little chamber in an attic area about 7 feet high and about 6×6′ with a 400 watt high pressure sodium lamp to simulate sunlight and provide warmth.

Raising anything requires that you provide good enough to optimal conditions for that organism to grow, mate, and reproduce. We could get them to grow to adulthood, but no mating.

These guys could really be the key to the Fish Food Project. What if we could take chicken offal, feed it to the larvae and then feed those larvae to the fish? Then , take the fish offal and feed it to larvae and take those larvae and feed it to chickens? That should be a pretty healthy loop, right?

We are currently working on a dedicated area for raising BSFL, like a small greenhouse, where proper temperature and humidity can be controlled. Perhaps, we can drum up some romance then.

Here are the notes to the first attempt:

First week: Started with 20 gallon bin with two 3/4″ PVC tubes at a 45ish degree angle with cardboard as a place for laying eggs. Tube number one leads to a bucket for collecting larvae. Tube number two leads to compost. I placed some partially field composted cow manure and a very old piece of tomato in as a food source. There is a 400watt full spectrum hps lamp in the room to provide some UV light. I read somewhere UV light is required for mating. Also in the chamber is some compost and partially composted horse manure outside of the bin to encourage the larvae that crawl up tube number two to pupate and emerge as adults.


Second week:
The tomato dried up. It’s drier in there than I thought. Added the butt of an old burrito for a food source because the larvae did not seem lively enough in the manure. There are pockets of larvae gathering under the old tomato rind and various locations of the manure. No other species of flies in there which is good.

Burrito is gone. Most BSFL under the small part of tortilla that is left. Looking lively. Added some moisture to cow pie. Going to add another food source. Added some discarded rabbit feed along with some rabbit pellets. Mixed them together in a bucket with some water. Poured the pasty mixture into bin near the piece of tortilla.

BSFL evenly dispersed in the rabbit manure/discarded food mixture. It also appears they have spread it out in the bin. Added some water, but forgot it was domestic. Argh. It’s chlorinated.

Pretty steady 70F and 50% humidity. They’ve moved the rabbit manure discarded food evenly around the bin. Added putrefied pansies from a wall garden to see if they’ll like them.

They loved the putrefied pansies. Mmm… Anaerobic treats! Environment is 70F and 50% RH.
They’re getting bigger.

Pretty much the same as last time. You can hear them moving around. They are fairly lethargic though. Getting bigger.

Added some water as the feedstock was somewhat dry. Still pretty slow. You can hear them moving around. Some are pretty big while others have not grown much. 84F

Checked the min/max and it was 55F and 88F with 53% humidity. 71F midday today. Was hot over weekend. Still not much change. They are moving around. Lots of gnats now. Added an old apple and banana peel.

Apple completely gone except for peel. Banana is going quickly. They are getting much bigger. Found a couple black smaller ones. Not sure if they’re dead or are pupating. None have climbed the ramp. It might be too steep.

Apple remnants have the most larvae. Sandwich butt also a big hit. Going to install another way out in case the existing ramps are too steep.

There are a lot of darkened larvae. They aren’t moving. Not sure if dead or pupating. I guess the ramps are too steep or not as accessible as they would like.
There are still some white larvae that move. Some white ones that aren’t moving too.
Finding that the dark larvae in the bin are indeed pupating and just never made it out like they did before. The cool temps 65-70F (they like it 85-90) make them slow to go from larval stage to pupation. The ones that don’t move would decompose if they weren’t alive, so it should still be interesting moving forward. Hopefully, they’ll emerge. Might do a little transplant outside the bin with some.

It’s 53F and they aren’t moving. Too cold.

Most larvae are dark in color. Couple white ones wriggling. They’re either pupating or dead. Starting new bin design.

Finally! One adult soldier fly spotted.


More adults have emerged Sean observed two possibly mating on 5/6.
Added moisture to the compost and manure in the room so the adults have choices outside the bin to oviposit.

They still have not bred. Need to create more appealing environment.

Will do new trial in a hoop house or another area on the ranch.

Edit 9/10/14: We have learned that suppliers often do something to sterilize the grubs so they will not reproduce. This makes a lot of sense in light of our experience with this trial.

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