Beech Bark Disease - Signs and Symptoms

Signs and Symptoms

The first sign that is visible is a woolly, white, waxy covering that the beech scale insect secretes. This sign can be observed covering small areas or most of the tree. The amount of waxy material observed depends on the population of the beech scale insect on that tree. The Neonectria fungi also show signs of its presence. An early sign is what looks like a bleeding spot on the tree. A reddish-brown fluid will ooze from the wound site, giving it this appearance. Later, perithecia will form around the dead spot, which is another sign of the disease.

Symptoms of beech bark disease can be observed in the foliage and on the bole of the tree. Symptoms affecting the foliage are yellowing, becoming small and sparse, and remaining on the tree during the summer time. Trees that display a thin, weak crown may persist for several years but may also die without displaying any symptoms. Symptoms that are noticeable on the bole are the cracking of the bark, the formation of cankers, and beech snap. Beech snap is a result of the fungi and insect weakening the wood, which makes it susceptible to being blown over by wind.