Authors familiar with green and blue moulds of citrus had mistaken the fungus for P. italicum and dismissed its unique features as variations due to particular environmental conditions. To date, P. ulaiense has been reported in Argentina, Arizona, Australia, California, Florida, Italy, New Zealand, South Africa, Taiwan, and Texas. In recent times, P. ulaiense has been reported in Egypt as a postharvest pathogen of orange fruit.
Experts knowledgeable about green and blue moulds of citrus mistakenly identified the fungus as P. italicum, attributing its unique features to environmental conditions rather than recognizing it as a distinct species. As of now, P. ulaiense has been documented in various regions worldwide, including Argentina, Arizona, Australia, California, Florida, Italy, New Zealand, South Africa, Taiwan, and Texas. In recent years, P. ulaiense has been found in Egypt to be a postharvest pathogen affecting orange fruit.