Uszaian Tree Grub is a Food Rare Commodity exclusively sold by Guest Installation in the Uszaa system.
This grub was introduced to the system from Lave, in an attempt to create a wildlife reserve for endangered species. Unfortunately the grubs mutated and evolved in their new environment, and the project failed. The evolved grubs were found to have a delicious flavor and surprising texture, and have since become a delicacy.
— In-Game Description