The Xylonomycetes are a class of fungi,[2] which holds 2 orders of Symbiotaphrinales Baral & E. Weber,[3] and Xylonales Gazis & P.

[4][5] During a culture-based survey of living sapwood and leaves of rubber trees (Hevea spp.)

Multilocus phylogenetic analyses reveal that this new lineage came from the radiation of the Leotiomyceta class which generated several other classes including Arthoniomycetes, Dothideomycetes, Eurotiomycetes, Geoglossomycetes, Lecanoromycetes, Leotiomycetes, Lichinomycetes and Sordariomycetes.

[1] Within the superclass of Pezizomycotina, the 6 classes (including Pezizomycetes and Orbiliomycetes) were monophyletic apart from Xylonomycetes.

As the yeasts are transferred vertically via the ovipositor of the female inset to the egg surface.