Effects of nutrient medium on various-age larvae of Hermetia illucens (Diptera, Stratiomyidae)

The saprophage Hermetia illucens (Linnaeus, 1758) (Diptera, Stratiomyidae) plays a crucial role in the processing of organic wastes, thus contributing to the achievement of the global goals of sustainable development. However, its introduction in the European Union led to intense discussions about the expended application of this insect in new spheres. The article considers a laboratory culture of the fly H. illucens as an innovative nutritional product. The objective of the presented study was assessing the influence of nutrition medium on the dynamics of gains in the mass and biochemical composition of live larvae of the fly. In particular, we measured the mean gain in mass of the larvae over the period of consuming the diet, vitality of the larvae, and the content of protein, fat, ash, and water. In the studies, we tested seven diets for fly larvae in relation to the dynamics in their mass gain. The studies revealed that wheat bran and soybean meal led to the highest parameters of mass of the larvae at all development stages, with the highest gains measuring 10.15 and 10.76 g, respectively. Based on those results, the diet of larvae was further optimized: the main component, wheat bran, was supplemented with the following additional ingredients: soybean meal, yeasts, glucose, and vitamin В9. Such a composition of diet promoted gain in the mass of the larvae, which on average accounted for 14.06 g. The same changes were observed in the accumulation of proteins and fats – 16.8% and 20.4%, respectively, which may suggest heightened nutritional value of the larvae. Due to the high adaptability and varying abilities of biochemical composition, one can select an artificial medium in cases of different proportions. This study confirmed that larvae of the fly can be a source of protein and fatty acids for the food industry in the future and thus improve the qualitative and nutritional characteristics of end products.