Diplodia sapinea is colonizing the native Scots pine (Pinus sylvestris) in the northern Baltics

For the northern Baltic region, Diplodia sapinea (Fr.) Fuckel, a well-known around the world pine pathogen, was first recorded in Estonia on Austrian pine (Pinus nigra Arn.) in 2007. Wider monitoring of the fungus was promptly started. Shortly, in 2012, the native Scots pine (P. sylvestris L.) was found symptomatic: first in Estonia, then in Latvia, and in 2013 in north-west Russia. Several individuals of exotic Mountain pine (P. mugo Turra) and some Bosnian pines (Pinus leucodermis Ant.) were also found to be infected. By the end of 2013, the front of the northward enlargement of the range of D. sapinea had reached to central Estonia. Early detection and continuous monitoring of this pathogen on native and introduced ornamental pine species will support forest and green belt management specialists with timely information, if an epidemic, as it occurred previously with the invasive Dothistroma needle blight, would emerge.