
A disease native to Asia, white pine blister rust was introduced separately into both eastern and western North America early in the 20th century. In both cases, the pathway was seedlings of native eastern white pine imported from European nurseries where they had become infected.
All native white pine are susceptible. Economic impact has been most acute on the two large commercial species, western white pine and sugar pine, and studies in the Pacific Southwest Research Station have identified some resistance genes in these species.
But ecological damage has also been severe on high elevation species such as whitebark and limber pines in many places. Research on managing high elevation species is ongoing in the Rocky Mountain Research.