Hi Jill, 54,66% of all the Italian Cantalupo's actually live in the Campanian region, so it was very probable your ancestor came from there. This is made more probable as he boarded from Naples, which is in that region.

Also, you can find the percentages here: <http://elenco.libero.it/elencotel/public/RicercaPerProvince.jsp?nome=&regione=campania&cognome=cantalupo> and it looks like the 2 province in which there are more Cantalupo's are Salerno and Naples. Fabio