I got 1,000 small bsfl....and I thought they will develop to"large" then my container started to Develop small flies, a bunch before the larvae grew to 'large'
I bought small three weeks ago and have kept mine at room temp (68) in damp coconut coir in large Tupperware with fruits and veggies on top for gutload. They eat a ton and have grown a lot bigger. No flies or pupae yet...