Scappe is part-owner of Coraopolis-based RBS Consultants. He was first elected to Moon's school board in 1999.
Mustio, R-North Fayette, in January that he will vie for departing state seat in the November race. Pippy, R-Moon, said last month that he will not seek re-election.
Mustio, who was elected to the state legislature in a 2003 special election, is also seeking re-election for the state house.
He may face Republican competition for Pippy's seat as well as his own. Mt. Lebanon business owner D. Raja, who in November to become Allegheny County Executive, has been circulating petitions for the race, according to the Pittsburgh Post-Gazette.
The newspaper also reports that Republican Ron Steele, who serves on the Moon Area School Board, has filed a petition to run for Mustio's seat in the 44th district. Steele was to a two-year term on the school board in November. He is managing director of the Pittsburgh-based Regency Consulting Services.
The deadline for candidates to file for November's election is Thursday.
Check back with Patch for more.