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Black Soldier Fly - Reproduction Then and Now

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As a short reminder, our project aims to raise Black Soldier Fly larva on food waste for tilapia feed. We want to breed a large colony in order to have a continuous supply of larva. Currently we are still trying to expand the colony size, so all mature larva are put into slightly damp soil to develop into flies. In the future when the colony is large enough, we plan to save only a small portion of mature larva for breeding and use the majority of larva for fish feed. In order to breed flies need to mate in flight, natural sunlight, 82F-100F, 30-90% humidity, and moisture on a plant for flies to drink off of. We initially built a 38”x 40”x 38”screened-in cage that contained a live plant, soil for larva to metamorphosis in, rolled corrugated cardboard for flies to lay eggs in, and a small food source to under cardboard to entice egg laying. The basement space was kept at 90F, ~80% humidity, and had a small window for light. This system did not allow for consistent metamorphosis and absolutely no egg laying. We suspect there was not enough natural light. We later learned that cardboard could potentially harbor bacteria that cause the eggs to be not viable. So we moved the whole breeding cage to our heated greenhouse to give the developed flies more natural light. However, after moving the cage outside the larva stopped developing into flies. This is probably because it became too cold at night. A table covered in plastic made a small room , giving the effect of a small greenhouse inside the larger existing greenhouse. This stayed warm enough for larva to develop into flies (although this was unintentional, read on to Wintering Over wiki-edit). We could potentially cover and heat the separate breeding cage in the greenhouse, but as of now we don’t have space for it. Larva undergoing metamorphoses inside the food bins were unintentional, but did allow for the colony to survive and flourish. It occurred more frequently during warmer weather than during cooler weather. The flies stayed mostly in the eaves of the greenhouse, mated, and laid eggs directly back into the larva bins. This has sustained our larva population since last May. It might be useful for a famer who is looking for very low maintenance BSF system and has a warm space to raise the larva, such as a chicken coop. I have heard that it could be detrimental to the population to have flies lay directly back into larva containers by causing colony collapse, but so far it’s unclear if that’s accurate and it has not been a problem in our system. We want to be able to collect all larva that mature so we can hand select how many larva go to fish food, and how many are saved to be breed, so larva developing directly in food bins is not ideal. We welcome new ideas and suggestions on the best ways to breed BSF!