Is attaching themselves to the body of a whale yucca moths can feed while moving through nutrient-rich water true?

No, that statement is not true. Yucca moths do not attach themselves to the bodies of whales or any other large animals to feed. Instead, yucca moths have a symbiotic relationship with yucca plants, where they pollinate the plants and lay their eggs in their flowers, and the larvae feed on some of the developing seeds.