Microbiota and their functional profiling across the life cycle of the blow fly Hemipyrellia ligurriens.

The blow fly, Hemipyrellia ligurriens (Diptera: Calliphoridae), is an ecologically and medically important species, particularly in forensic entomology, where its developmental stages aid in minimum postmortem interval estimation. Microbial diversity in insects is known to fluctuate dynamically across developmental stages. However, the mechanisms governing microbial community assembly, symbiont transmission, and functional roles in H. ligurriens remain largely unexplored. This study utilized 16 S ribosomal RNA gene amplicon sequencing to characterize the microbiota structure and functional metabolic potential across all life stages of H. ligurriens. Microbial composition varied significantly across developmental stages, with distinct assemblages characterizing each stage. Proteobacteria (synonym Pseudomonadota), Firmicutes (synonym Bacillota), and Bacteroidota consistently dominated across all life stages and rearing media, suggesting their essential role in host development. Notably, natural strain flies exhibited significantly greater microbial diversity than laboratory-derived counterparts. While microbial diversity was comparable between male and female flies from both strains, sex-specific microbiota appeared exclusively in the natural strain. Functional metabolic profiling suggests that microbiota co-evolve with their host, playing vital roles in immune regulation and pathogen defense. This study provides the first comprehensive microbiota profile of H. ligurriens, offering novel insights into its potential applications in forensic entomology, maggot debridement therapy, and insect health management.