Effect of Dietary Meat Content on Weight Gain, Mortality, and Pre-Pupal Rate in Black Soldier Fly (Hermetia illucens) Larvae

Abstract

This study aimed to determine the protein content and the ratio of meat that can be added to the diet of black soldier fly (BSF) larvae for the sustainable recycling of food waste using insects. We conducted experiments feeding refined diets to BSF larvae with adjusted protein content and diets with minced pork, and analyzed the correlations between dietary nutrients and larval weight gain, mortality, and pre-pupal rate. The nutrient that was positively correlated with increased larval body weight and pre-pupal rate in both experiments was nitrogen-free extract (NFE). Diets with high concentrations of minced pork showed higher mortality of BSF larvae and were negatively correlated with dietary NFE content. It has been suggested that BSF larvae have reduced body weight and survival due to excessive protein and fat in their diet. Depending on the raw material and ratio of food waste, it may be necessary to adjust dietary protein and fat contents before treatment. The results of this study suggest that the NFE content of a larval diet influences the larval weight gain, mortality, and pre-pupal rate of BSF larvae in a great extent, a finding that has not been reported by previous studies.

Evaluating the Efficiency of Black Soldier Fly (Hermetia illucens) Larvae in Converting Mackerel Head Waste into Valuable Resources

“…Higher MH proportion in BSF larvae feed increases protein and fat content while decreasing carbon sources. Since digestible carbohydrate content is the main source of energy for most insect species including BSF larvae [47], it is essential for optimal growth [48]. The BSF larvae reared on high carbohydrate-content feed (55%) showed higher yields than low carbohydrate content (35-45%), although they contained varying amounts of protein (10-24%) [49].…”

Immune Responses of the Black Soldier Fly Hermetia illucens (L.) (Diptera: Stratiomyidae) Reared on Catering Waste

“…Indeed, as previously observed [ 40 , 41 ], a higher growth rate was recorded in insects fed a protein-rich diet that, being more balanced, provided the macro- and micronutrients necessary for insect development [ 42 , 43 , 44 ]. A higher meat inclusion rate in the diet (80%), compared to the one used in our trials (10%), led to an extreme larval weight and survival reduction due to excessive protein and fat intake [ 45 ]. The lowest larval final weight and ADG observed in the FV diet are probably due to the lower protein content of the diet itself [ 46 ].…”

“…A lower survival rate has been recorded in insects fed a NatOvo and an FVBM diet, while the FV diet allowed the highest survival rate. As previously discussed, a fruit and vegetable-based diet, with the lowest protein content, negatively affects the growth rate, ADG and final production of larval biomass, but at the same time ensures higher larval survival [ 45 , 46 ]. A higher final production of larval biomass was observed when feeding the insects a NatOvo, FVBM, and FVBD diet, respectively.…”