EPPO Platform
on PRAs

Rapid assessment of the need for a detailed Pest Risk Analysis for Helicotylenchus dihystera


The key factor to determine is whether the organism is present in Europe. Definitive proof is awaited for the reasons set out in this PRA. If present, it will probably be restricted to protected crops and areas of Europe with hot summers, but although many reports have been documented no definitive molecular evidence currently exists.

This rapid assessment shows: 

Risk of entry: Likely based on frequency of interceptions and fact that most of these will be in association with ornamentals and therefore the pest will arrive already associated with a host and growing media.

Risk of establishment: Unlikely to establish outside based on known distribution, however there is high uncertainty regarding its ability to survive cold conditions, so establishment could be moderately likely. Likely to establish under protection. 

Economic impact: Low impact based on likelihood of confinement of pest to growing media of potted host ornamentals and protected cultivation. 

Endangered area: Glasshouse crops, in soil or pots, are at risk, but the risk to outdoor crops is not known 

Risk management: Most treatments may reduce population levels and reduce spread but not eradicate. Difficult to prevent establishment by treatments other than destruction.


  • Helicotylenchus dihystera


  • Begonia
  • Beta vulgaris
  • Cucumis sativus
  • Rosa


Type File Size
Pest Risk Analysis Download 103,49kB

PRA Area

  • United Kingdom