Effect of poultry litter-based diet and sexual ratios on the fecundity and viability of Tenebrio molitor: insights for sustainable rearing and circular bioeconomy

The growing demand for sustainable alternative protein has driven interest in the farming of edible insects, such as Tenebrio molitor. This study evaluated the effects of diets with different proportions of poultry litter (PL) and sex ratios on the fecundity and larval viability of T. molitor, aiming at the reutilization of organic waste. Diets containing 0%, 50%, and 100% PL were tested, combined with male-to-female ratios (1:1, 1:3, 1:6, and 1:9). The results indicated that the inclusion of 50% PL balanced productivity and sustainability, increasing fecundity and larval viability. In contrast, 100% PL compromised development and reduced fecundity, possibly due to toxicity and nutritional imbalance. The 1:3 sex ratio maximized fecundity and average larval weight, regardless of diet. In PL-based substrates, the 1:1 ratio resulted in heavier larvae, suggesting that lower female densities reduce resource competition. These findings highlight the potential of T. molitor for organic waste valorization and sustainable protein production. Future studies should investigate strategies to mitigate the negative impacts of higher PL proportions and explore the interaction between microbiota, population density, and reproductive performance.