Influence of Rearing Systems on the Genetic, Nutritional and Medicinal Properties of Edible Insects: A Critical Review

Insect farming is gaining momentum for its potential to strengthen food security and the sustainability of food systems. However, how rearing conditions shape the overall quality of edible insects remains poorly understood. Optimization strategies are suggested on the basis of this critical review, which synthesizes 96 studies, selected from 866 database records and supplemented by citation searching, on the effects of rearing systems and genetic, nutritional, and medicinal properties of edible insects. At least 41 species are farmed under conventional, semi-intensive, or intensive systems, and their quality behaves as a plastic rather than intrinsic trait, modulated by nutritional, environmental, husbandry-related, and biological factors acting on both phenotype (plasticity, epigenetic regulation) and genotype (drift, inbreeding, selection). Reported effects are substantial. For instance, in Tenebrio molitor, crude protein falls from 64.3 to 54.4 g/100 g dry matter as temperature rises from 22 to 28 °C, lipid content peaks at 47.4% at 31 °C, and artificial selection has raised larval weight by up to 39% within 16 generations. Conventional and semi-intensive systems show high batch-to-batch and seasonal variability, whereas intensive systems deliver more stable, standardized production at higher cost and lower consumer acceptability. Genetic selection emerges as a promising but underexploited lever, although conclusions remain qualified by study heterogeneity.