Adult BSF seek out dark, moist places close to decaying organic matter, depositing upwards of 400 or more eggs per egg clutche. It is not uncommon to observe mating females depositing their egg clutches on top of and adjacent to other egg clutches left behind by other females. Whereas adult BSF mate in midflight, females prefer to deposit their egg clutches in dark, tight nooks and crannies protected from direct sunlight.
Humidity markedly affects egg viability. As the relative humdity in the vicinity of the egg clutches falls below approximately 50%, egg viability rapidly declines due to dessication of the eggs. Newborn larvae emerge from the egg clutches in approximately four days, and immediately begin crawling toward the decaying waste where they begin feeding and growing off the waste at a rapid rate.
A single egg has an average mass of approximately 25 micrograms. Newborn larvae feeding off food scrap waste tyipically grow over a period of three weeks under optimal conditions into the preupa stage of their life cycle reaching a mass of approximately 200 mg, an 8000-fold increase in their mass over that of the egg from which they first emerged.
Commonly available plastic bins and totes can be easily converted into BSF Propagation Bioreactors (PBR's) as illustrated in the accompanying pictures. Adult females attracted to food waste added to the PBRs enter through holes drilled into the walls and lids of the PBRs and deposit egg clutches inside the PBRs which subsequently hatch in a matter of a few days. New larvae hatching from the egg clutches proliferate in the waste. Upon reaching the prepupae stage in their life-cycle they self-harvest from the waste through vent holes drilled through the walls of the units, pupate, re-emerge as adults, mate and return to the PBRs in sustaining their colony. PBRs can be used as a simple means of propagating and growing BSF on food scrap wastes.