Welfare approach on Hermetia illucens rearing: preliminary results and perspective.

The black soldier fly, Hermetia illucens, has become well-recognized as part of a circular economy for agriculture (Lalander et al., 2019; Lu et al., 2021). Many parameters affect its rearing: substrate composition, environmental conditions, technological, and regulatory limitations (Cortes Ortiz et al., 2016; Vantomme et al., 2012). Moreover, welfare evaluation through the application of the “Five Freedom of Brambell’s Report” (5F) has been proposed by the International Platform of Insects for Food and Feed as fundamental for improving the performance (IPIFF, 2021), but data on this aspect are scarce. A set of trials (T1, T2, and T3) has been organized at BEF Biosystems (Italy) to determine how best the 5F can be integrated into the rearing process of the black soldier fly. The best dietary regime for larval growth (T1) among vegetarian, carnivorous, and omnivorous diets was determined, and then different feeding rates (T2; 50, 100, 200 mg/gg/larvae) were evaluated, defining the best conditions for growing performance, substrate, and mortality reduction. Finally, density parameters (T3) were assessed, evaluating 5, 10, and 15 larvae/cm 2. All three experiments had three replicates for each treatment; moreover, the trials were conducted with both groups of 100 and 2000 larvae (T1, T2), from 320 to 960 and from 3045 to 9135 larvae (T3). Preliminary results highlighted the importance of an omnivorous dietary regime, with a feeding rate of 100 mg/gg/larvae and a density of 10 larvae/cm 2. Chemical analysis and data evaluation with statistical software are ongoing to obtain clear and strong evidence of the results.