[2] Exobasidium vexans is an obligate pathogen of Camellia sinensis, causing a disease commonly known as Tea Blister Blight.

E. vexans prefers to attack the young leaves on the lower half of hosts and presents as small yellow translucent leaf spots which progress to lesions.

Atmospheric spore concentrations are present throughout the year, but are lowest January through May when relative humidity and rainfall is decreased, and direct sunlight duration is increased.

During these months it has been found to produce abnormally thick walled spores, in addition to the usual basidiospores, that resist germination in vitro.

(Ajay et al. 2009) The wet season in tea growing regions runs June through December and creates conditions favorable to endemic infection.

Due to the short life cycle of E. vexans it is critical to apply chemicals weekly when conditions are favorable for disease.