Dothistroma needle blight, caused by the fungus Dothistroma septosporum, is present throughout Scotland, with the greatest impact in the north and north east. The disease affects a large range of conifers, but especially pine. The principal species currently infected in Scotland are Corsican pine, lodgepole pine and Scots pine.

The fungus affects the needles of the infected tree, which eventually shed. This can continue year on year and gradually weaken the tree, significantly reducing timber yields. It can also eventually lead to mortality.