Caused by the fungal pathogen Diplodia, this deadly fungal evergreen tree disease spreads rapidly by wind and rain. Pine tip blight normally targets fir trees that are over thirty years old and that have suffered wounding and damages. The infected tree will first exhibit stunted needles and thinning growth. The needles will then turn brown and die. The brown needles begin on the lower branches first and gradually progress upward. Excessive cankers and black specks on needles and pine cones manifest as the disease progresses. Although it is choice host tree is Austrian pine, pine tip blight will infect any mature, weakened evergreen tree. Left untreated, this fir tree nemesis will destroy the tree; therefore, contact an arborist that treats sick trees promptly if your evergreen tree has brown needles.