Catillariaceae

The family Catillariaceae consists of crustose lichens that are frequently found on the bark of woody plants. It is essential to clarify that these organisms are not plant pathogens. They are epiphytes that derive their nutrients from the atmosphere and moisture, rather than extracting resources directly from the host plant's tissues.

While Catillariaceae are not a disease in the botanical sense, their presence on fruit trees often serves as a bioindicator. An abundance of lichen growth usually suggests that the tree is in a state of reduced vigor, lacks adequate sunlight, or is situated in an environment with high air humidity and poor circulation, which prevents the bark from drying quickly.

Common hosts for these lichens include mature fruit trees such as apple, pear, and plum varieties. They thrive on the stable, aging bark of trees that have not been maintained through regular pruning or trunk cleaning, finding a perfect microhabitat for their slow development.

The impact of Catillariaceae on horticultural crops is largely indirect. Excessive coverage of the bark can trap moisture, create a refuge for pests like scale insects or mites, and potentially interfere with the tree's natural respiratory processes through the lenticels, although they do not cause tissue necrosis themselves.

Management and preventative strategies are primarily focused on maintaining tree vigor and bark hygiene. Recommended practices include:

• Implementing systematic pruning to optimize airflow and sunlight penetration within the canopy.
• Periodic mechanical cleaning of trunks and main branches to remove dead bark and epiphytic growth.
• Applying horticultural oils or copper-based treatments in early spring, which help inhibit the establishment of lichens and protect the bark integrity.