The first reports of the disease were made in Paris and other regions of France, Spain, Luxembourg and the Netherlands in 1907.

Its anamorph was easily distinguished from Phyllactinia guttata which had previously been reported to cause powdery mildew on oaks in Europe at low intensity.

Powdery mildew had already been reported from North America so it was thought that the new disease could have been imported on American oaks into Europe.

[1] Recently, molecular biology has provided new tools for identifying species and elucidating their relatedness.

A study of ribosomal DNA from 33 samples of oak powdery mildew from Europe showed that E. alphitoides contains identical sequences to Oïdium mangiferae, a major disease of mango in several tropical regions and Oïdium heveae, an economically important pathogen of the para rubber tree.

Despite it affecting the ability of leaves to photosynthesise, the effect is low and this is thought to explain why the disease has only moderate consequences for tree health despite heavy infections.