We have spotted our first adult black soldier flies in our bin! We setup our bin 2 weeks ago and added a started pack of black soldier fly larvae we bought from NW Red Worms. All of the larvae that crawled out of the bin were put in a bucket of sawdust. The idea was to let the first bunch live to become adults. When they return to the bin, their bucket sits under the bin, they will add their eggs and increase our black soldier fly count.
This morning we spotted our first adult black soldier flies inside the bin. Then later today when we checked on them again we spotted three inside the bin. We were really excited to see them and hope there will be lots more over the next few days. Here is a picture of our first adult black solider fly.
Is it one of ours or wild?
I have to admit, I don’t know if this black soldier fly is one of ours. It’s entirely possible that the smell of the barley in the bin has attracted a wild black soldier fly. Either way, we now have mature black soldier flies visiting our bin. Hopefully they are also laying eggs to help churn out lots of food for the chickens.
Even more now
Three days after we spotted our first adult black soldier flies we are seeing 15 – 20 of them at any given time when we open the lid on the bin. So far we haven’t seen any on the cardboard strips we placed there for laying eggs.
As I understand it, the black soldier fly takes about three days to reach sexual maturity after pupation. If my understanding is correct, they should begin mating soon. After that we should begin to see females laying eggs inside the bin. Over the next couple of days we will check the bin and vicinity for signs of mating black soldier flies.
Recently we decided to take on a new project and build a black soldier fly bin. The black soldier fly larvae is a fantastic composter and will eat about any organic matter. The larvae are terrific food for the chickens. They have a high fat and protein content and chickens absolutely love them. They will be fed scraps and spent barley we can get for free from a nearby brewery. After the initial cost of the materials to build the bin and the BSF larvae starter pack, we will be getting free chicken food.
Why black soldier fly instead of worms?
We looked into other composters like mealworms and just your standard worm. Here in NW Missouri, we can see 100 degree weather and periods of drought during our summers. Those two things are hard on regular worms. The BSF likes the heat.
Ultimately the deciding factor for us was when we learned we didn’t need to dig or sort out larvae to feed to the chickens. When they are ready to pupate from larvae to a fly they “self-harvest”. That is, they will leave the compost area to seek the soil to begin the transformation to a fly. With a correctly designed bin the larvae are going to be in a container after self-harvesting and ready to be fed to the chickens. We won’t have to touch them.
Picking a black soldier bin
We spent a fair bit of time watching different YouTube videos of the different bins available for the black soldier fly. There are commercially available bins made from plastic and home built models from plastic and wood.
Some of the plastic bins had a small hole for the larvae to drop through when self-harvesting. In several of the videos, I noticed the hole became partially blocked. Larvae were finding alternate routes from the bin and didn’t make it into the collection container. The ramp for the mature larvae to crawl was more complex than the simple wooden version we saw.
The wooden bins were larger and would easily accommodate more BSF larvae. I liked the simple collection system on them. Ultimately we elected to go with a wooden bin and to build our own. We bought some black soldier fly bin instructions through a website that also sells larvae. This bin was in one of his many BSF videos and the design was simple and looked easy to build. You can see the one we liked in this video.
Assemble and paint the black soldier fly bin
We pre-cut all the pieces for the bin on the table saw and assembled the bin near the chicken pen where it will ultimately be placed. The assembly was pretty easy and straightforward. The ramp for self-harvest did give me the business, but we got it done. We used a little caulk to seal up any small gaps to keep the larvae in the bin.
In this picture, you can see the bin and the ramp for self-harvest of the mature larvae. They will crawl up the ramp and be directed to the hole.
The BSF larvae will fall through this hole and into the bin below. We used some cheap plastic food storage bins from Walmart. You can see the food storage bin in this photo.
After applying several coats of an exterior white latex paint to the bin we added about three inches of sawdust to the bin. This will keep the larvae off the bottom of the box to prevent them from going through the drain holes.
Some pieces of cucumber were added to provide the larvae that arrived in the mail from NW redworms. Here you can see the prepared bin with food and larvae.
Paint to protect the black soldier fly bin
Because the black soldier fly bin is made with plywood it would not last long if left unprotected from the elements. We want to make this ban last more than a couple of years, therefor we decided to paint it. We went with a cheap can of exterior latex from Walmart and applied several coats. It will seal that plywood and help it last several years before needing replacement. Here is what the completed black soldier fly bin looked like after applying paint.
We have been working outside this week and thought we would provide an update on the greenhouse build progress. This greenhouse is being built over our 95 ton heat sink and is part of our geothermal heat sink greenhouse project. We are still a long ways off from having the the heat sink operational. You can see what we have accomplished in this picture.
Arch supports installed
Near the peak of the arches you can see a horizontal support. They are on all the arches except the two on the end, These supports will provide rigidity for the arches under heavy winds and snow loads. We don’t get lots of snow here in NW Missouri but we do generally see some every year. If we received lots of snow it would have been necessary to go with a different style of arch to support a heavy snow load. They’re held in place with a self tapping screw to keep them from moving.
Installing greenhouse hip boards
Both sides of our greenhouse will get a hip board and baseboard installed. You can see the partially installed hip board on one side of our greenhouse in the picture above.
In this picture you can see how we are securing the hip board to our arches. Notice the Tapcon screw installed through the top bracket. One bracket at each arch will get a Tapcon to prevent the hip board from moving. Each arch, with the exception of the two end arches, will have the hip board secured in this fashion. The two end arches will have a 3/8 inch hole drilled through the board and arch. A carriage bolt will be used to secure the hip board at each end.
After both sets hip boards are up we will install the base boards. Once those are on we will need to do a little back filling with dirt to help keep critters from getting inside.
After the base board work is complete the ends will need to be closed up and the door and door frames built. We will be framing in both ends with treated lumber that was reclaimed from our in the garden greenhouse. We are still sorting out the details of the end walls.
After the end walls are complete the grow boxes will be built and installed. They will be filled with sawdust and sand, mixed at 75 percent sawdust. We likely transplant seedlings into the grow boxes before pulling plastic.
The double layer of greenhouse plastic will be installed this fall once the temperature drops to around 60 degrees.
Our quest to be self reliant and grow a healthy garden