Shortening the Black Soldier Fly Life Cycle by Temperature‐Driven Genetic Selection to Enhance Alternative Protein Production

ABSTRACT In response to the growing demand for sustainable protein sources, insect mass rearing has emerged as a promising solution. The black soldier fly ( Hermetia illucens , Diptera: Stratiomyidae) is particularly valued for its ability to convert organic waste into high‐value feed ingredients. To improve the economic and environmental sustainability of BSF farming, we explored selective breeding as a tool to enhance thermal adaptation. We selected a BSF colony (Sel35) over 24 generations for fast growth at 35°C and compared it to a non‐selected laboratory strain (Ento2). Sel35 showed a consistently shorter life cycle than Ento2—by approximately 5 days at 28°C and 3 days at 35°C—alongside higher hatching rates and increased prepupal weight at 35°C, without compromising other fitness traits. Biochemical analysis revealed trehalose accumulation in Sel35, suggesting a metabolic adaptation to heat stress, while Ento2 showed a decrease at 35°C. Microbiota composition varied slightly across conditions but played a minor role, with a stable core community observed in both strains. These findings demonstrate that selective breeding can optimize BSF performance under high‐temperature conditions, highlighting its potential to support scalable, resilient, and sustainable insect protein production for future food, feed, and waste management systems.