A 34-year-old Louisiana man has pleaded not guilty to misdemeanor vehicular manslaughter for a crash that killed a Twin Falls motorcyclist in northern Idaho late last summer.      Taj Patrick LeCompte of Elton, La., entered his plea via telephone Friday in Magistrate Court in Bonner County. He was allowed to appear by telephone because his pregnant wife was very near her due date.  Idaho State Police said LeCompte was southbound on U.S. Highway 95 south of Sandpoint when he turned into the path of a northbound motorcyclist. LeCompte told investigators that he did not see 60-year-old Lawrence “Red” Barber until the “last split second” before the Sept. 8 collision. Barber died 10 days later at a Seattle hospital.  LeCompte has applied for a public defender.