In 1899,Ignazio Saietta arrived in New York fleeing a murder charge in Corleone. He was Giuseppe Morello's brother-in-law. Ignazio had acquired the nickname "Lupo" meaning wolf; suggesting an animal that preys on the weak.
Lupo was his last name, but sometimes he used his mother's surname Saietta (or was it Saitta, I read somewhere Saietta is a misspelling, but I am not sure). His parents were Rocco Lupo and Onofria Saietta, he used both surnames depending on the situation.
Changing his name would make sense since he was wanted on a murder charge. Thanks for the info.