Hermetia illucens L. (the black soldier fly) has received increased attention because of its great potential in converting organic waste into a renewable resource. The prepupae have high proportions of proteins and fats and can serve as feedstuff for livestock and as feedstock for biodiesel production. With the goal to upgrade the conversion of low-value organic wastes into high-value proteins and fat on a large scale, the effects of the feedstuffs food waste, pig manure, chicken manure, and cow dung on the reproductive potential and nutrient composition of H. illucens were evaluated. The intrinsic rate of increase of H. illucens fed food waste (0.1249 d^–1) was significantly greater than the rate of those fed pig manure (0.1167 d^–1), chicken manure (0.1154 d^–1), and cow dung (0.1049 d^–1). The ash content of H. illucens fed food waste (30.8 g·kg^–1 lyophilized prepupa matter (LPM)) was significantly lower than that of those fed chicken manure (37.6 g·kg^–1 LPM) and cow dung (49.5 g·kg^–1 LPM). The contents of crude fat, 372.4 g·kg^–1 LPM, and protein, 436.9 g·kg^–1 LPM, in prepupae fed food waste were the highest among the four treatments. The reproductive performance and prepupal nutrient composition indicated that food waste was the most suitable feed for H. illucens. The results from this study further demonstrate that the prepupae of H. illucens have great potential for use as a protein and fat source in animal feeds and as biodiesel material.