If you’ve decided to run an outdoor BSFL setup and use wild BSFL to manage your waste or feed your chickens . Your only real controls of environment are shelter, moisture and shade. If you’ve decided to attempt this indoors in a climate controlled space. You can have full control over the above as well as temperature, humidity and lighting.
If you’re using climate control you want to maximize either composting, or grub production. You’ve made a large investment and an ongoing investment in utility bills.
Let’s first look at greatest grub production. The largest conversion to grub mass occurs at a temperature around 27C (80F). Lower temperatures result in slower grub production but larger individual grubs. Higher temperatures mean more grubs but smaller average size. Often it’s said the 27C (80F) is “ideal”, well that may depend on your usage and need. A bait seller might profit more from a larger number of smaller grubs. If huge larvae aren’t needed and selling by the count higher temperatures are better.
Relative humidity around 60% provides excellent results for egg production. 60% is acceptable for larvae growth as well. Bin moisture should wet but not watery. Adding water too quickly to a dry bin can cause larvae to climb out of a bin. It’s easier to control moisture through food type. Too dry? Add wetter food, too wet? Add something with a lower water content. This is something you’ll get better at with practice.
Adult black soldier flies need a broad spectrum light source to reproduce. Grow lights can provide the spectrum needed. Mercury halide lights being cheaper to buy and producing heat. LED lights produce little heat, excellent light and lower energy bills. Whatever lights you choose the heat, safety and cost are factors to considered. Most breeders suggest leaving artificial lights on 24 hours a day. Adult flies only survive a few days. So maximize the possibility that females get fertilized. Adult black soldier flies also love to bask on plant leaves when seeking a mate. So some artificial or potted plants with larger leaves are beneficial as well.
Observation suggests the adult flies seem to reproduce with some temperature fluctuations. Do your adults seem hesitant to breed or oviposit? Simulating cooler overnight temperatures is something worth trying. Getting conditions right for soldier fly reproduction can be a bit of a guessing game. Keep records of what works and what does not. This way you’ll learn what works best for you.