 These forests have suffered recent declines due to infestations by the balsam woolly adelgid ("Adelges piceae"), a non-native insect that originated in Europe.It first infested Mount Rogers in 1962 and the entire U.S. population of Fraser firs suffered a 67% mortality rate since, although Mount Rogers was not affected as severely as other locations.Some researchers have proposed that air pollution in the form of nitrogen and sulfur compounds originating from power plants has been a source of stress to the Fraser firs, resulting in an increased susceptibility to the balsam woolly adelgid, but this relationship has not been confirmed.