Life Cycle
Two types of spores of this fungus germinate when moisture is present: conidia and ascospores. Conidia can quickly be carried from diseased plants to healthy ones by splashing rainwater, sprinklers or watering. In addition, the ascospores are discharged into the air and can travel between plants on a breeze or current. If they land on a moist leaf, ascospores germinate, infect the orchid host, and begin the cycle anew.
Although Phyllosticta does not kill an orchid, it may weaken the plant to the point where it easily falls prey to other pests or diseases.