Butterfly Dust

Moths only live in the Underground Jungle and they are not common, so this is a hunt rather than a farm. The workable approach is to clear and light a wide stretch of jungle and keep passing through it while you do other business down there. A dedicated moth setup is more effort than the single item it feeds.

On current versions nothing drops at all until you have taken down a mechanical boss, so an early jungle trip is wasted time if wings were the goal.

Butterfly Wings are the only thing it builds. If you end up with extra dust and no interest in flying with it, craft the wings anyway before you sell, because the finished pair is worth far more than the parts that made it.