Bridging the Gap: Scaling Up the Sustainable Production of the Yellow Mealworm with Agricultural By-Products—Insights into Larval Growth and Body Composition

Amidst the escalating global demand for protein-rich livestock feed, there’s an urgent call to explore innovative alternatives. Insects, renowned for their rich protein, lipid, and nutrient profiles, offer a sustainable solution. Integrating agricultural waste into insect diets emerges as a promising strategy to alleviate rearing costs. However, large-scale investigations into by-product valorization remain limited. Thus, our study aims to evaluate Greek agricultural by-products—brewer’s spent grains, rice bran, oat and maize by-products, and animal feed mill leftovers—as potential feedstock for Tenebrio molitor larvae, an insect species that is authorized by the European Union for both livestock feed and human consumption. In this study, the larval growth and body composition were assessed in commercial trays, unveiling optimal performance with rice bran and brewer’s spent grains. Conversely, larvae fed with animal feed mill leftovers and maize by-products displayed suboptimal outcomes. These findings underscore the potential efficacy of integrating locally produced agricultural by-products into T. molitor commercial production. Such an approach not only addresses the growing demand for protein-rich livestock feed but also offers a sustainable solution to agricultural waste management. In conclusion, our research contributes valuable insights towards developing economically viable insect farming.