Specific Features of Organic Waste Bioconversion by Hermetia illucens Fly Larvae (Diptera: Stratiomyidae, Linnaeus, 1758)

Abstract

The data from our work and the literature data are summarized, and some regularities of bioconversion of the studied organic waste by Hermetia illucens larvae are elucidated. Waste is both an environmental and feed substrate for an insect. The following stages of waste bioconversion were identified based on the temperature change of the organic substrate: (1) delay in the temperature change (lag-phase); (2) temperature increase (heating); (3) stationary conversion at elevated temperature; and (4) sharp temperature drop to the level of ambient air temperature (cooling, or final stage). This indicates that two processes occur simultaneously during larval development in the substrate: microbial aerobic compositing of the substrate and larval digestive activity. A limiting factor of larval development is a fiber content in the substrate exceeding 7%. The type of fodder affects the mass fraction of protein and fat in the larvae; furthermore, an elevated starch content in the substrate (above 500 g/kg of substrate) facilitates fat accumulation in the insect body.