It was concluded that a daily rate of 100 mg chicken feed per
larva met both the demand for a nutrient-rich prepupal output
and high organic matter degradation within a short time
(Figure 3).
Using the digestible energy as a reference value, the
present results can be projected to different kinds of organic
waste (Table 5). Depending on larval density and waste
source, a daily load of 3–8 kg m–2 can be applied to a black
soldier fly CORS system. Needless to say that the calculated
feeding rates presented in Table 5 are based on rough estimations
and have to be interpreted carefully as they
depend on other factors such as material moisture or fibreAssuming a larval density of 5 larvae cm–2, a prepupal dry
mass of 2.5 kg could be harvested per life cycle and m2
(145 g m–2 day–1) when fed with a waste equivalent of 100 mg
chicken feed larva–1 day–1.
For farmers and small entrepreneurs in low- and middleincome
countries, biomass produced by black soldier flies
can be an additional income derived from this low-tech
based waste treatment. It has been shown that even an irregular
waste input (e.g. due to seasonal or personal fluctuations)
the larva population remains alive albeit with reduced
metabolic activity until the next food/waste input.
This study has taken a major step towards the quantification
of a black soldier fly CORS system. However, our results
were obtained from small-scale laboratory experiments.
Implementation at a larger scale in situ will lead to new challenges,
especially under changing environmental conditions
(e.g. humidity, incident solar radiation, predators/parasitoids),
the design of the treatment system (operability and
usability), and the fate of problematic waste contents (e.g.
heavy metals, pathogens) will be new elements to tackle.