Stage-Specific Microbiota Transitions Throughout Black Soldier Fly Ontogeny

Area of Science:

• Insect microbiology
• Sustainable protein production
• Waste management

Background:

• Growing global protein demand and waste management challenges necessitate alternative solutions.
• The black soldier fly (BSF; Hermetia illucens) offers a dual solution by converting organic waste into valuable protein.
• Microbial communities significantly influence BSF development, behavior, and reproductive success, particularly oviposition.

Purpose of the Study:

• To investigate the microbial communities throughout the BSF life cycle.
• To specifically characterize the egg surface microbiota and trace its origin.
• To understand how microbial composition changes during BSF maturation and before oviposition.

Main Methods:

• Analysis of bacterial communities in various BSF life stages: larval haemolymph and gut, pupal pulp, ovipositor wash, eggs (ovarian, post-oviposition, surface-sterilized), and adult abdomen.
• Comparison of microbiota in larvae raised on sterilized versus non-sterilized feed.
• 16S rRNA gene sequencing to profile bacterial communities.

Main Results:

• Distinct bacterial profiles were observed across different BSF life stages.
• Larval stages showed dominance of Enterobacteriaceae (e.g., Morganella, Escherichia, Proteus).
• Egg surfaces were predominantly colonized by Burkholderiaceae (Burkholderia-Caballeronia-Paraburkholderia), indicating a microbial transition before oviposition.

Conclusions:

• Microbial communities undergo significant transformation during BSF maturation, especially preceding oviposition.
• While some dominant bacteria persist, the overall community composition shifts, influencing egg development.
• Understanding these microbial dynamics, particularly egg surface microbiota, can optimize BSF rearing for enhanced protein production and waste management.