Whole genome sequencing reads data of 288 individuals of black soldier fly (Hermetia illucens) for artificial selection study
Artificial selection is the most common method of genetic improvement for agricultural species to maximise economic viability and production yields. However, the insect livestock industry remains in its infancy and the potential impact of artificial selection remains poorly characterised. Genetic improvement of the black soldier fly, Hermetia illucens, has only recently been explored. However, previous experiments did not investigate trade-offs among life history traits or explore the genetic architecture behind the trait of interest. Here, we performed experimental evolution to investigate the response to selection on body size, a key commercially relevant trait. Three replicate size selection experiments were performed for seven generations with a mean population size of 1,703 individuals per replicate. Control lines were maintained in parallel without selection. We obtained phenotypes for 110,707 individuals and found selection for increased pupal body size generated a strong and repeatable response. An overall 15% improvement in body size was produced over the seven generations, which lasted nine-months. Narrow-sense heritability estimates showed pupal body size to be a highly heritable trait (0.36). Selected lines also showed significant improvements in larval growth rate (+19%) larval- (+16%), prepupal- (+18%), pupal-weights (+19%), larval development time (+7%) and increased average protein content (+14%). However, there was a significant trade-off with female pupal development being significantly slower in large lines (-6%).  A rapid and polygenic genomic response was found in the selected line, with multiple genes involved in increased body size with convergent regions showing signatures of selection on chromosomes 6. This study demonstrates that artificial selection can introduce substantial genetic improvement to the insect livestock industry on a rapid timescale, whilst highlighting the importance of genetic bottlenecking. This information can be used to inform future breeding programs for enhanced insect farming productivity and sustainability.