Insect production for feed and food is rapidly expanding, driven by the efficiency by which some insect species can convert waste-products into valuable and sustainably produced protein sources. This study proposes a novel way to enhance production of insect cultures by using male-killing (MK) endosymbionts to manipulate sex ratios in insect populations which may lead to increased productivity. Our hypothesis is that female-biased populations, induced by MK endosymbionts, can have higher biomass output. First, we show that female larvae of the black soldier (Hermetia illucens) (BSF), are generally larger, grow faster, and have higher feed conversion efficiency than males, supporting the potential of female-biased BSF populations within this species. As a proof of concept, we next provide data from experiments with Drosophila melanogaster and Drosophila pseudotakahashii-model insect populations harboring the MK endosymbionts Spiroplasma and Wolbachia, respectively-demonstrating that MK-infected lines can have extreme female-biased sex ratios. Depending on the species, these populations exhibit higher prepupal mass, faster development, and improved feed efficiency, indicating a potential for greater biomass yield in infected lines. Combined, our results suggest that sex ratio manipulation via endosymbionts may offer a biological tool that can boost insect production for food and feed, thus serving as a basis for further investigation. We suggest that this technology may contribute significantly to insect farming by increasing efficiency and sustainability.
Laursen et al. (Sun,) studied this question.