Matt Saager wrote:No kidding??? I've never heard that.
I have had some BSF's in the worm bin before, a few larvae, not too many though.
The bin is a converted horse water trough, with a plywood lid that sits pretty tight.
I wonder if it would still get over-run with BSF's ??
Here are some points to keep in mind and/or consider -
Black soldier flies begin as an egg, which takes 102-105 hours to hatch. They emerge as a larvae that is already voraciously hungry and rapidly consumes any and all food available. BSF are not picky about what kind it is. After about 2 weeks the larvae reach maturity. If the temperature is not ideal or there is not enough food, they could take several months to mature. At that time, their mouth is replaced by an appendage that helps them crawl out of the container, and they stop eating. Now, the mature adult BSF will fly away to mate and die.
Worms process about three times their weight in food scraps per week. If you assume five pounds of worms would be a substantial quantity and that they would consume 15 pounds of food per week. Compare this to a BSFL colony in a 2 foot diameter container that can process 11 pounds of food EVERY DAY! Even with 10 pounds of worms you would still be limited to just 30 pounds of scraps per week.
Worms require a fairly specific environment with regards to moisture, ph, and temperature. Different sources recommend keeping worms at a minimum of 54 and up to 70-84 degrees, depending on the source of the information. BSFL are much more hardy and tolerant. In addition, the BSF willing to eat anything. They can survive temperatures as low as just above freezing up to about 100 degrees. Once some BSFL were tested by being submerged in isopropyl alcohol for two hours, and they survived.
You see, if enough BSF can enter or reproduce enough in your worm bin, they can outnumber by the faster reproduction and with a greater appetite, they can starve your worms very quickly.
BSF are GREAT at breaking down food waste and converting it into living protein. They are not real good soil builders, their digestive track is short. They can eat things in a very short amount of time like meats and diary, that otherwise would compromise a worm bin. They shred the waste first and release moisture. This requires adequate drainage while the earth works at a slower pace preventing the quick release of cellular moisture. BSF are niche dominant and will raise the temperature in your worm bin to a level not comfortable for the worms and eat all the available food.
Worms are GREAT at building soil. They have a long digestive track, their castings are valuable and they are able to break down some of the harder to digest plant matter that has little nutrient content for the BSF. They do not tolerate high-temperatures as the grubs and take a longer time to reproduce. Worms do not reproduce as quickly as grubs do and are, therefore more valuable as a recycling organism. Harvesting worms to feed to chickens only makes sense when you have a lot of worms relative to the number of chickens.
My conclusion: Do like nature does... When something dies in the forest, maggots are the first line of decomposition... Earthworms finish this process and create fertile soil. We, too, can simulate this in different stages and locations. Recognize their merits and values and try not to improperly combine or short-cut the process.