I have been trying to set up a black soldier fly farm at the ECHO Florida office and have been struggling to attract them naturally. We have a fairly large bin that has two inclines on each side that lead into buckets. I started it in August/September but was unable to attract any flies so we purchased the larvae to start. They took surprisingly long to mature and fall into the side buckets, but I did harvest them in small batches every now and then. After some time, I did see one fly near the bin; however, I never saw any eggs on the cardboard I had set up. Around mid December, I seemed to have none left in the bin.
I would really like to attract local flies than to purchase the larvae. Tips and tricks would be much appreciated.
Sounds like you need to include a breeding chamber which is screened in and has the right atmosphere, lighting in particular, for them to mate and produce eggs. Once the eggs are laid in the breeding chamber by the adults then you can move them to your substrate for making larvae. If you send me an email I can put you in touch with several experienced black soldier fly producers that can give you better trouble shooting than myself. janzen200@yahoo.com
I am not a professional soldier fly farmer by any means, but I have been able to successfully attract soldier flies every summer and am only a few hours away from ECHO Florida, so maybe my input will be helpful.
It is worth noting that black soldier flies (BSF) are most active during the summer months. From what you shared, it looks like you started at the end of their most active season.
What are you using as bait? There are two things that have worked for me: whole oats and rabbit manure. For the oats, I have always used whole oats still in the hull the same as you can get at the feed stores for horses. In a bucket, place 2-3 quarts of oats and cover with water and let soak overnight. The goal is to get them to soak up as much water as possible without having water sitting at the bottom. Leave uncovered or partially covered for several days to several weeks in a mostly shaded area. I usually have ours sitting in our pole barn. The BSF just show up. For the rabbit manure, it is pretty much the same. Get it nice and wet but without standing water maybe throw a bit of hay on top and let it sit… Please note that I have not experimented with additional bait types. I am sure there are many other things that work.
Hopefully you will find this helpful. Happy farming!