It makes sense that if the adults live for up to 8 days they must at least need to drink. If I learn anything about BSF mouth parts I'll let you know. Hopefully I'll speak with Dr. Olivier again soon, and if so I'll ask him about it.
It's not just orange peels that the BSF larvae avoid, the same is true of most fruit and vegetable skins. I've seen them eat entire cucumbers, potatoes and squash except for the skins. Once I added some pecans and they even left the super thin outer "skin" of the shelled nut. Like humans, BSF larvae can't digest cellulose, so they simply pass on anything with a high cellulose content. That's why they won't eat grasses.
