If this is the correct manifest, it does mention that
Pasquale's father is Leonardo.
First Name: Pasqualino (born about 1895) Last Name: Di Lallo
Ethnicity: Italy Last Place of Residence: Petrello Inf., Italy
Date of Arrival: June 10, 1913 Age at Arrival:  18y    Gender:  M    Marital Status:  S  Ship of Travel: Sant Anna Port of Departure: Naples
Manifest Line Number: 0002
This manifest mentions that he would be joining his cousin Michele on Victor Street, in Allegheny PA. It also mentions that his father Leonardo is the closest relative (and his mother - though no name mentioned) in Italy.
page 1
http://ellisisland.org/search/shipManif ... 0106%2ETIF
page 2
http://ellisisland.org/search/shipManif ... 0106%2ETIF
There is this manifest of a Nicola (possibly a brother) - born 1891 that also mentions that the father is a Leondardo...
First Name: Nicola (born about 1891) Last Name: Di Lallo Ethnicity: Italy, So. Italian Last Place of Residence: Petrella, Italy Date of Arrival: May 09, 1910 Age at Arrival:  19y    Gender:  M    Marital Status:  S  Ship of Travel: Venezia Port of Departure: Naples Manifest Line Number: 0020
http://ellisisland.org/search/shipManif ... 0243%2ETIF
and
http://ellisisland.org/search/shipManif ... 0243%2ETIF
If census info / and sibling manifests could be found it would help more... I'm sure there is something out there... but for now...