Jews are attested in Sicily since the oldest times.
Jews were an high percentage of the population in Sicily before the expulsion of the year 1492.
After the persecution some Sicilian Jews ran away, some converted and some secretly practiced Judaism for generations (Anusim).
As you know the surname means dove and it is the equivalent to the Hebrew Jonah.
Some Palumbo who were surely Jews are attested in Sicily in the 16th century and were persecuted by the Inquisition because Judaizing after the expulsion .
They are attested in the towns of Nicosia Palermo, Piazza Armerina
Nardo Bonomi Braverman
Firenze – Italy(Author of http://www.jewishgen.org/infofiles/Italy/italian.htm)