The natural history of the black soldier fly, Hermetia illucens: insights from complete mitochondrial genome sequences.. Natural history of the Black Soldier Fly Hermetia illucens

The Black Soldier Fly (BSF) Hermetia illucens is a cosmopolitan fly, heavily used by industrial companies to reduce biowaste and produce protein and fat for poultry and aquaculture feed. However, the natural history and the genetic diversity of the BSF is poorly known. In this study, we analysed nearly 700 CO1 sequences distributed on the whole planet leading us to the discovery of 52 haplotypes that segregate into 10 major haplotypes. We also sequenced and assembled about 60 mitochondrial genomes allowing us to date the separation events of the different haplotypes: more than two million years for the oldest branches. This worldwide cryptic genetic and genomic diversity is even mirrored at local scale in France in which we found 8 major haplotypes found sometimes in sympatry. Our data resolve the phylogenetic relationships between the major lineages and give insights into natural history and the numbers of BSF neo-introduction at global and local scales. Our results indicate that the genetic and genomic diversity of commercial BSF stock is very low and these brood stock participated in the dissemination of the BSF in the wild. Taken together these results call for a better understanding of the genomic diversity of the BSF to unravel possible specific adaptations of the different lineages for industrial needs and to initiate the selection process.