At the Allegheny SAF winter meeting in 2009, foresters learned of a naturally-occurring fungus that was killing Ailanthus in southern Pennsylvania. Recently, results from a Penn State study were published discussing the application of that fungus as a means of biocontrol. The disease is called Verticillium wilt of Ailanthus (V. nonalfalfae), and since that time it has now spread to three states. In two regions in Pennsylvania and Virginia, this disease is considered epidemic.
By injecting a cluster of five Ailanthus trees along a transect every 1,000 feet in a stand, researchers killed all Ailanthus trees within three years (slightly longer for very large stands). While resprouting did occur, all sprouts were similarly infected and died within several years. Much of this research was conducted on Pennsylvania public lands, including a public forestry demonstration site in Canoe Creek State Park, Tuscarora State Forest, State Game Lands, and also on lands administered by the Army Corps of Engineers.
A copy of the study can be found by clicking here.