Truncated Higiant enhances the bioconversion ability of Hermetia illucens.

The black soldier fly (BSF), Hermetia illucens, has garnered attention for its proficiency in converting organic waste into valuable biomass. In the context of rapid population growth and urbanization, BSF with higher bioconversion efficiency is in urgent need. One promising approach to improve the efficiency is generating new lines by molecular breeding, which has succeeded in plants and various livestock. Here, we developed a BSF strain with an enhanced bioconversion efficiency using CRISPR/Cas9-mediated genome editing. By knocking out the gene giant (gt) in BSF, we obtained individuals with larger size and higher reproductive capacity. Notably, the mutant strain increased the bioconversion efficiency of food waste by 13.10%, and exhibited consistent performance across diverse organic waste substrates. In addition, our study elucidates multifaceted roles of gt in larval growth and developmental plasticity. Moreover, mutants showed reduced reproductive competitiveness against WT in mixed populations. In conclusion, our study provides a superior and safe insect chassis for biomanufacturing and underscores the potential of molecular breeding to enhance efficiency in BSF farming for sustainable organic waste recycling.