Long-term storage of Hermetia illucens (Diptera: Stratiomyidae) larvae

Abstract

The production of black soldier fly larvae (BSFL), Hermetia illucens (L. 1758) (Diptera: Stratiomyidae), for organic waste conversion and sustainable biomass production is gaining increasing interest. Maintaining sufficient larval stocks is essential for continuous production, yet practical methods for long-term storage remain limited. This study evaluated the effects of temperature (15{degrees}C and 27{degrees}C), larval density, and substrate coverage on BSFL survival and growth over a 12-week storage period. Storage conditions significantly affected substrate moisture, larval survival, and development. Covering the substrate with hydrated straw pellets and aluminium foil reduced water loss and minimised maintenance requirements. The highest survival rate, approximately 70% after two months of storage, was obtained at 15{degrees}C using this combination of hydrated straw pellets and aluminium foil. Following storage, larvae showed high survival and pupal hatching rates under standard rearing conditions, indicating that prolonged storage did not compromise larval fitness. These results demonstrate that storage at 15{degrees}C with hydrated straw pellets and an aluminium cover provides a practical, low-maintenance strategy for maintaining reserve BSFL stocks and ensuring a stable supply of larvae for production and research purposes.