Weeping Beech Diseases With Red Spots

Beech Bark Disease

• Red spots occur on a weeping beech tree as the result of a fungal attack known as beech bark disease. The illness is precipitated by the feeding of an insect called the wooly beech scale, with the fungus entering the tree at the feeding site, killing the bark and, at the same time, the scale insect. The red spots are fungal fruiting bodies called perithecia, and grow in bright, red clusters on both living and dead beech bark.

Nectria Fungi

• Some perithecia spots are a lighter, salmon or pink in color, but all these weeping beech diseases with red spots are the result of infection by three species of Nectria fungi.

  Nectria galligena is native to North America, while Nectria coccinea var. faginata traveled from Europe. In many cases, the native version is the first to attack a beech tree and is then followed by the European disease.

Red Spots

• The red spots on a beech -- the sexual fruiting bodies of the nectria fungi -- are loaded with sacs of spores that are released into the wind each fall and transferred to adjacent specimens. On some beeches, the infestation is so severe that the numerous red spots appear to turn the color of the bark completely red, while in other cases, the red spots are minute and difficult to view. Before the red spots develop, tiny white or pink collections of fruiting bodies may be present on the bark of the beech.

Considerations

• Beech bark disease typically does not develop until the beech scale insects have been present on the tree for between three to six years. The infection is extremely lethal and older or weak beeches are likely to succumb to the attack. Additionally, the disease makes it easier for other insects and pathogens to cascade upon the beech. Only 1 percent of beeches are estimated to be completely resistant to the disease. The best preventive technique is to ensure and encourage the health and vitality of the weeping beech tree.