Black soldier fly larvae adapt to different food substrates through morphological and functional responses of the midgut

Modulation of nutrient digestion and absorption is one of the post-ingestion mechanisms that guarantees the best exploitation of food resources, even when they are nutritionally poor or unbalanced, and plays a pivotal role in generalist feeders which experience an extreme variability in diet composition. Among insects, the larvae of black soldier fly (BSF), Hermetia illucens, show an astonishing adaptability to feeding substrates, including a variety of waste organic matter, without any dramatic impact on their development. This strongly suggests that the larvae can set in motion post-ingestion processes to match their nutritional requirements. In the present study we address this issue by investigating how BSF larval midgut adapts to nutritionally poor diets.