Insects’ superpower: waste bioconversion by Hermetia illucens larvae.

Over the coming decades it will be mandatory to face the problem of feeding the constantly increasing world population, limiting the depletion of food resources, the unsustainable exploitation and exhaustion of agricultural land and water, and environmental pollution. The higher demand for human food will require an increasing production of feeds for livestock, poultry, and aquaculture. Another serious concern is represented by food waste disposal since one third of food produced globally is wasted. These critical challenges require innovative solutions to produce more food with fewer inputs, less environmental impact, and reducing the food waste. Insects must be considered as a high potential source of animal protein for feed production, as well as a primary agent for organic waste reduction and bioconversion into usable protein products. In particular, the dipteran Hermetia illucens is a good candidate for the bioconversion of waste substrates into high quality insect proteins. Despite the great interest toward the optimization of rearing methods of H. illucens, information on the biology of this insect remains scarce, especially on the larval midgut and fat body, two organs of key importance for the bioconversion process. The present research aimed at analyzing the morphofunctional properties of the larval midgut. Moreover, we evaluated how the diet provided to the larvae can affect the microbiota composition and the morphological and functional properties of the midgut, as well as the accumulation of storage molecules in the fat body. Finally, a study about the feeding habits of the fly, an aspect that has been neglected so far, was performed.