The ESENIAS-TOOLS WG4 meeting on alien fungi species was organised on 17-18 November 2015, in Novi Sad, Serbia.

An invited lecturer was Prof. Dr. Giuseppe Venturella, coordinator for fungi species at the OPTIMA (The Organization for the Phyto-Taxonomic Investigation of the Mediterranean Area). In his lecture „Invasive species: what's about fungi?“ he presented important issues on alien fungi species and necessity of creating a regional list. There are several dozens of alien fungi species recorded in the ESENIAS region so far, while the predicted number is cc. 600 species.

The main conclusions of the meeting were:

• The alien fungi species is one of the least studied taxonomic group in the ESENIAS region;
• Most of the alien species are very similar morphologically to native fungi species in the region and their identification is difficult;
• Although there are studies on alien phytopathogenic species of importance in agriculture and forestry, few of them are published;
• Further investigations and involvement of more taxonomy experts on fungi are needed in the next years to compile the list of alien fungi species in the ESENIAS region.