Rapid Evolutionary Adaptation to Diet Composition in the Black Soldier Fly (Hermetia illucens)

Abstract

Genetic adaptation of Hermetia illucens (BSF) to suboptimal single sourced waste streams can open new perspectives for insect production. Here, four BSF lines were maintained on a single sourced, low-quality wheat bran diet (WB) or on a high-quality chicken feed diet (CF) for 13 generations. We continuously evaluated presumed evolutionary responses in several performance traits to rearing on the two diets. Subsequently, we tested responses to interchanged diets, i.e., of larvae that had been reared on low-quality feed and tested on high-quality feed and vice versa to evaluate costs associated with adaptation to different diets. BSF were found to experience rapid adaptation to the diet composition. While performances on the WB diet were always inferior to the CF diet, the adaptive responses were stronger to the former diet. This stronger response was likely due to stronger selection pressure experienced by BSF fed on the low-quality single sourced diet. The interchanged diet experiment found no costs associated with diet adaptation, but revealed cross generational gain associated with the parental CF diet treatment. Our results revealed that BSF can rapidly respond adaptively to diet, although the mechanisms are yet to be determined. This has potential to be utilized in commercial insect breeding to produce lines tailored to specific diets.

Applying nutritional ecology to optimize diets of crickets raised for food and feed

“…Similarly, black soldier fly larva (Hermetia illucens) reared for 13 generations adapted to a lowquality diet and grew heavier larva and pupa [82]. To perform multigenerational diet experiments requires time, space, and resources, factors that are species-dependent; the time, space, and resources to rear thousands of D. melanogaster for 100 generations is much less compared to rearing thousands of G. sigillatus for 100 generations.…”