Charles Leland's 1899 work Aradia, or the Gospel of the Witches, does not say.

Prayer for Aradia was created in 1985.

There is no one by the name of Arcadia in the Night World series by L. J. Smith. However, there is a character named Aradia. She is the witch who made the prophecy about the people with blue fire. She is blind and is the Maiden of the witches.

Edit: Arcadia is the name that the human, Maggie Neely, thought to be Aradia's, because Aradia was sick and somewhat mumbling when she introduced herself. Don't worry. You were actually more accurate than you thought.

Aradia Cruz was born on May 30, 1988, in Seville, Andaluca, Spain.