Beech bark disease is a disease that causes mortality and defects in beech trees in the eastern United States, Canada and Europe. In North America, the disease occurs after extensive bark invasion by Xylococculus betulae and the beech scale insect, Cryptococcus fagisuga. Through a presently unknown mechanism, excessive feeding by this insect causes two different fungi (Neonectria faginata (previously Nectria coccinea var.
Beech bark disease is a condition that leads to mortality and defects in beech trees in eastern North America, Canada, and Europe. In North America, the disease develops after extensive bark invasion by Xylococculus betulae and the beech scale insect, Cryptococcus fagisuga. Through an as-yet-unknown process, excessive feeding by this insect triggers two different fungi (Neonectria faginata, formerly Nectria coccinea var.