Pines (Pinus), hemlocks (Tsuga), spruces (Picea), larch (Larix) and Douglas-fir (Pseudotsuga menziesii), Red cedar (Juniperus) and Western red cedar (Thuja plicata).
Trees exhibit poor growth, chlorotic leaves and sometimes dieback of the top.
Presence of perennial fruiting bodies (carpophores) on the trunk or branches. Fruiting bodies vary widely in thickness and size and are broadly attached, with a rather sharp to obtuse margin, and are woody hard. The underside is yellowish-brown to greyish-brown with irregularly shaped pores (Photo 1 and. 2).
Infected heartwood is often light red to reddish brown (Photo 3).
Later on, small lens-shaped white pockets appear in the decayed wood.
The decay extends in lines along the annual rings and forms concentric rings (Photo 4).
Timber quality is reduced. The decayed wood is often highly resinous.
Decay columns commonly extend 10 meters or more, rendering the entire trunk useless for lumber.
Infected trees can survive many years, but the decay predisposes the trees to breakage.
The spores (basidiospores) are dispersed by wind, and enter the trunk through wounds all over the year. Dispersal of basidiospores is at its maximum in spring and autumn.
The fungus grows up slowly in the heartwood, (only 5-10 cm /year).
Older trees are more susceptible to damage by this fungus.
Avoidance of wounding during silvicultural operations.
In managed forests, harvest should take place at a relatively young age.
On trees with ornamental value, the wounds must be protected with mastic such as copper-based formulations.
Biological control with Ascocoryne sarcoides is applied successfully in Canada, but this product is not registered in Spain, Portugal or France.