Beech Bark Disease
Beech bark disease causes defects and mortality in beech trees. The disease occurs after bark invasion by the scale insects, Xylococculus betulae and Cryptococcus fagisuga. Feeding by these insects causes the fungus (Neonectria faginata (previously Nectria coccinea var. faginata)) to produce cankers on the bark of the tree, which leads to the formation of lesions around the tree, eventually resulting in canopy death.