Courtesy: Ken Reese

Muskoka Beech are under attack by the Beech Bark Disease, an insect-fungus complex. This disease has now pretty much spread through the entire range of the beech species. In the insect stage of the disease, the crawler nymphs, less than a millimetre, hatch in late summer, soon cover themselves in a white, woolly wax filament and feed by inserting their stylet into the inner bark of the tree. 

The scale insect looks like a white tuft and the colonies can be numerous enough to lend a whitish cast to the bark. By spring the adult stage of the scale continues to feed and lays its eggs in the summer. The insects do not kill the tree but do weaken it over time.

In the fungus stage of the disease, the fungal spores are carried by wind and rain and over a period of 2-10 years, enter the feeding wounds left by the scale insect,. The fungus feeds on the inner bark and cambial layer causing small cankers to appear on the surface of the smooth bark.

These cankers continue to grow and often within 3-6 years girdle the stem. The conspicuous clusters of fruiting bodies of the sexual stage appear in the fall as red coloured bulbs some 2-3 mm in height and can be numerous enough to give a reddish cast to the bark.

For the cottager, damage can occur from dead branches or the collapse of the tree. Careful inspection of your beech treecan identify the insect and the fungal stages of the disease and precautionary measures can be taken.