in many nations around the world the butterfly symbolizes hope for all inactive persons desiring sex. It is said that if a butterfly is to rest upon you that your sexual deficiences and bad luck (for lack of a better term) will be cured
It could be a symbol of multiple things depending on the context, a writer pointing out a butterfly could show purity or beauty, whereas a butterfly coming out of its cocoon can symbolize either the...
As much meaning as you care to put on them. In certain cultures they may have specific meaning, but, like black cats and walking under ladders, the meaning is cultural rather than scientific.