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Simple Summary Due to the high sustainability of insect farming, the possibility to farm insects as a food and feed source seems to be very promising. Reusing and enhancing food waste is possible by using it as a substrate for the growth of insects. In this context, black soldier flies (BSF) can grow on a wide range of substrates, transforming them into valuable biomass. In this trial, four different substrates were used and were evaluated for their suitability for larvae rearing: broiler feed as standard diet, a vegetable diet, a diet with 50% of vegetables and 50% of butchery wastes, and a diet composed by 75% of vegetables and 25% of butchery wastes. Butchery wastes can be suitable, but they must be well combined with other ingredients to balance the high level of lipid and the low content of protein, and vegetable wastes can be an appropriate candidate. Vegetable and butchery wastes are easy to find and collect, and in the present trial, they showed interesting potential for BSF larvae growth producing, at 22 days of age, insects with interesting chemical characteristics. The use of vegetable wastes reduced the level of the reactive oxygen species in insect hemolymph, suggesting a positive effect of larvae welfare. Abstract Hermetia illucens larvae (five days old) were farmed on broiler feed (control diet), a vegetable diet (V100), a 50% of vegetable diet + 50% of butchery wastes (V50 + B50), and a 75% of vegetable diet + 25% of butchery wastes (V75 + B25) to evaluate their suitability. Ten kilograms of substrate and 6000 larvae composed each replicate (nine per group). Larvae were weighed and measured every two days until the 25% developed into prepupae. Larval mortality and growing indexes were calculated. Substrates, larvae, and frass chemical composition were analyzed. Larvae oxidative status and stability were measured in hemolymph and body. The V100 larvae showed the lowest live weight, length, thickness, and growth rate but had low mortality rate and high substrate reduction index and protein conversion ratio. The V100 larvae had similar protein to and lower lipids than the control ones, while the V50 + B50 and V75 + B25 larvae contained higher lipids and lower protein than the others. Despite the vegetable wastes, at different levels, the reactive oxygen species content decreased in hemolymph, and the V100 diet depressed growth performance and should be avoided. The use of butchery wastes combined with vegetable ingredients can be a suitable alternative to balance the high level of lipid and the low content of protein.

Sicilian Naturalistic News: 3 Hermetia illucens; 4 Ancylolomia tripolitella; 5 Gavia immer; 6 Bucanetes githagineus; 7 Clubonia terrestris.

Modulation of nutrient digestion and absorption is one of the post-ingestion mechanisms that guarantees the best exploitation of food resources, even when they are nutritionally poor or unbalanced, and plays a pivotal role in generalist feeders, which experience an extreme variability in diet composition. Among insects, the larvae of black soldier fly (BSF), Hermetia illucens, can grow on a wide range of feeding substrates with different nutrient content, suggesting that they can set in motion post-ingestion processes to match their nutritional requirements. In the present study we address this issue by investigating how the BSF larval midgut adapts to diets with different nutrient content. Two rearing substrates were compared: a nutritionally balanced diet for dipteran larvae and a nutritionally poor diet that mimics fruit and vegetable waste. Our data show that larval growth performance is only moderately affected by the nutritionally poor diet, while differences in the activity of digestive enzymes, midgut cell morphology, and accumulation of long-term storage molecules can be observed, indicating that diet-dependent adaptation processes in the midgut ensure the exploitation of poor substrates. Midgut transcriptome analysis of larvae reared on the two substrates showed that genes with important functions in digestion and absorption are differentially expressed, confirming the adaptability of this organ.