Waxy cup fungus

Waxy cup fungus, scientifically known as Neodasyscypha cerina, is a type of Ascomycete fungus that primarily acts as a saprophyte on decaying wood, though it is frequently identified in cases of bark necrosis on weakened woody plants. It belongs to the order Helotiales and is distinct due to its specialized fruiting bodies.

The pathogen thrives by colonizing the bark of deciduous and sometimes coniferous trees. The fungus produces small, wax-like, yellow-to-orange apothecia that are highly characteristic and visible to the naked eye, appearing in clusters on the surface of infected branches or trunks, particularly in cool, moist environments.

Host susceptibility varies depending on the tree's health status. Broad-leaved species like oak, birch, and beech are common targets. The fungus typically exploits existing wounds, pruning cuts, or dead tissue resulting from frost, insect damage, or drought, using these sites as entry points to colonize the inner bark layers.

Symptoms are identified by the presence of localized necrotic lesions on the bark, which may become discolored and sunken over time. As the fungal infection progresses, it disrupts the flow of nutrients in the outer bark, leading to cracked surfaces where the conspicuous, cup-shaped fruiting bodies emerge in large numbers.

Control and prevention center on rigorous forest sanitation and tree health management. Minimizing physical damage to the bark is essential to deny the fungus entry. In managed stands, infected material must be removed and destroyed to prevent spore dispersal. Maintaining optimal stand density and vigor is the most effective long-term strategy against colonization.

• Remove and destroy infected branches and debris.
• Minimize bark wounding during forestry operations.
• Maintain tree vigor through proper site management.
• Monitor stands for early signs of fungal apothecia.