Development and Biomass Composition of Ephestia kuehniella (Lepidoptera: Pyralidae), Tenebrio molitor (Coleoptera: Tenebrionidae), and Hermetia illucens (Diptera: Stratiomyidae) Reared on Different Byproducts of the Agri-Food Industry

Abstract

The aim of this study was to evaluate five agro-industrial byproducts (apricots, brewer’s spent grains, brewer’s spent yeast, feed mill byproducts including broken cereal grains, and hatchery waste including eggshell debris, fluff, infertile eggs, dead embryos, and egg fluids) or mixtures thereof as food diets of Ephestia kuehniella (Zeller), Tenebrio molitor (L.), and Hermetia illucens (L.). Eleven out of 26 tested combinations allowed the first instar larvae to reach the adult stage. Results showed that bioconversion parameters and biomass composition can vary depending on the diet composition, especially in the case of E. kuehniella and H. illucens, whose nutritional requirements seem more complex than those of T. molitor. Tenebrio molitor was able to develop in almost all byproducts. However, only when T. molitor was fed with suitable mixtures of byproducts the development parameters were similar to those obtained with the standard diet. The best results in terms of bioconversion parameters were obtained by feeding H. illucens with a diet including dried brewer’s spent grain, feed mill byproducts and brewer’s spent yeast. The larvae of these three species can be considered interesting from a nutritional point of view, because of their high protein and fat content. However, the fatty acids profile of H. illucens larvae, with high proportions of saturated fatty acids, seems less healthy for human consumption compared with those of E. kuehniella and T. molitor.

Rearing Tenebrio molitor and Alphitobius diaperinus Larvae on Seed Cleaning Process Byproducts

“…For a relative tenebrionid species, the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), triticale was significantly better for larval growth than hard bread wheat and durum wheat, indicating the high nutritional value of this cereal and its potential as insect feeding substrate [ 32 , 33 ]. In a recent work studying the suitability of various byproducts of the agri-food industry, T. molitor larvae were offered feed mill byproducts (mainly broken cereal grains), which resemble the byproducts tested in our study [ 21 ]. Although the authors of that study do not provide information regarding the type of cereal grains that composed this particular byproduct to allow a direct comparison with the results of our study, feed mill byproducts supported T. molitor larvae development, however, larval mortality was higher and larval growth was lower than when fed with the control diet [ 21 ].…”

“…In a recent work studying the suitability of various byproducts of the agri-food industry, T. molitor larvae were offered feed mill byproducts (mainly broken cereal grains), which resemble the byproducts tested in our study [ 21 ]. Although the authors of that study do not provide information regarding the type of cereal grains that composed this particular byproduct to allow a direct comparison with the results of our study, feed mill byproducts supported T. molitor larvae development, however, larval mortality was higher and larval growth was lower than when fed with the control diet [ 21 ].…”

“…Both species are approved as aquafeed ingredient in EU [ 12 ], whereas T. molitor was the first insect species to acquire an EU-wide approval for human consumption [ 13 ]. The upcycling and bioconversion of several organic side-streams and wastes by T. molitor has been studied by several studies [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. For instance, an olive pomace-enriched substrate up to 25% enrichment sufficiently supported T. molitor larval growth, providing a means for exploitation, as well as management, of the olive processing byproducts [ 22 ].…”

Impact of Diets Including Agro-Industrial By-Products on the Fatty Acid and Sterol Profiles of Larvae Biomass from Ephestia kuehniella, Tenebrio molitor and Hermetia illucens

“…Recently, we investigated the bioconversion of agro-industrial by-products with three different insect species (i.e., Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae), T. molitor, and H. illucens) to develop an efficient waste management strategy [25]. This study included the assessment of 26 diets containing different agro-industrial by-products (non-marketable apricots, brewer's spent grains, brewer's spent yeast, feed mill byproducts including broken cereal grains, and hatchery waste including eggshell debris, fluff, infertile eggs, dead embryos, and egg fluids) or mixtures thereof.…”

‘Insects as Food and Feed: If You Can’t Beat Them, Eat Them!’—To the Magnificent Seven and Beyond

“…Two of the contributions explore the use of novel substrates as insect feed, addressing one of the research priorities as defined by IPIFF (2019) . Specifically, Riudavets et al (2020) investigated the suitability of organic agro-industrial byproducts for the rearing of the Mediterranean flour moth, Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae), T. molitor , and H. illucens , whereas Galassi et al (2021) studied the effect of organic side-streams from agro-food industries on larval biomass production, development time, nutritional composition and microbiota of H. illucens larvae. Another research topic of high interest is the exploitation and reuse of insect rearing residues, which was directly addressed by Gärttling et al (2020) .…”