I am aware of these words that mean "butterfly":
- 蝶々 (Is the alternate form of チョウチョ more common than 蝶々? Because 蝶々 would be チョウチョウ instead and it seems ウ is removed because of shortening)
- バタフライ (I think this is mainly used in the context of swimming; バタフライで泳ぐ, and in the context of chaos theory; バタフライ効果. Can it be used for the insect?)
Which is most commonly used to generally refer to the insect? And when are the less common (if any) forms used? What are their nuances if any?