Biological and productive aspects of the black soldier fly Hermetia illucens (Diptera: Stratiomyidae) in meal moth rearing residues Ephestia kuehniella (Lepidoptera: Pyralidae)

The inadequate disposal of organic waste generated in insect biofactories breeding biological agents may become a potential environmental problem. The use of Hermetia illucens (Diptera: Stratiomyidae) may play an important role in the circular economy of this process, transforming waste into high-quality biomass. Therefore, this work aims to analyse the degradation of organic residues of Ephestia kuehniella (Lepidoptera: Pyralidae) production using the black soldier fly. Four types of waste from the moth breeding process were evaluated: residues of the meal diet when moth larvae were in the last instar; residues of the meal diet when completing the cycle; residues formed by webs in the pupation process mixed with residual exoskeleton, and residues of dead adults. These residues were tested in isolation and in mixtures of 50%, using as control a standard diet composed of chicken feed. Survival rate, development time, emerged adults, weight, size, residue reduction, and bioconversion were evaluated. The residue used in diets affected the total development time of H. illucens. The mean number of survivors differed from 87% to 74% for larvae that reached the pre-pupal stage. The viability of pre-pupae to adult stage ranged from 54% to 6% for residue treatments and 97% for the control. Differences in the growth and weight gain of larvae were significantly different. The rate of residue reduction from 54% to 80% and bioconversion into larval biomass were satisfactory. However, regarding adult emergence, the numbers show variations, indicating that certain residues are not suitable for the maintenance of fly breeding.