Based on this PRA report, Litylenchus crenatae was added to the EPPO A1 List of pests recommended for regulation as quarantine pests in 2026. Measures for plants for planting of Fagus spp. are recommended.

The aim of this PRA report is to assess the status of Litylenchus crenatae as candidate for listing on the EPPO A1 and A2 Lists of pests recommended for regulation as quarantine pests. EPPO recommendations for regulation are normally made either on the basis of EPPO Pest Risk Analyses (PRAs) prepared by Expert Working Groups (EWGs) or PRAs developed by EPPO member countries for the EPPO region, or PRA reports based on national PRAs or EFSA PRAs. This PRA report is based upon a GB PRA (DEFRA, 2025), an Express PRA for Ireland (McGee, 2024) and additional references used to apply the national PRAs to the wider EPPO region. A Quickscan prepared by the Netherlands is also available (NVWA, 2020).    

Conclusions

Some of the main uncertainties:

 • Whether the pest should be considered a single species or as more than one sub-species 

• The distribution in Asia

• The relative susceptibility of F. sylvatica, F. orientalis and F. grandifolia

 • The means of spread

 • The climatic tolerances of the pest

 • The potential role of microorganisms detected alongside L. crenatae in symptom development

 L. crenatae meets all the criteria to be recommended by EPPO for regulation as a quarantine pest. In particular, this nematode is absent from the EPPO region and could enter, establish, spread and cause impact to Fagus trees. Phytosanitary risk management measures are recommended to reduce the risk.