Risk to plant health of Ditylenchus destructor for the EU territory

The EFSA Panel on Plant Health performed a pest risk assessment onDitylenchus destructor, the potatorot nematode, for the EU. It focused the assessment of entry, establishment, spread and impact on twocrops: potato (Solanum tuberosum) and tulip (Tulipaspp.). The main pathways for entry ofD. destructorinto the EU and for spread of this nematode within the EU are plants for planting, including seed potatoesandflower bulbs. These commodities are also the main targets for the assessment of the impact.A modelling approach was used to quantitatively estimate entry, spread and impact. Literature andexpert judgement were used to estimate model parameters, taking into account uncertainty. A baselinescenario with current pest-specific phytosanitary regulations was compared with alternative scenarioswithout those specific regulations or with additional risk reduction options. Further information isprovided on the host range ofD. destructorand on survival of the nematode in soil in the absence ofhosts. The Panel concludes that the entry ofD. destructorwith planting material from third countries issmall compared to the yearly intra-EU spread of this nematode with planting material. Changes inpest-specific regulations have little influence on entry of the pest as other non-specific regulation alreadylead to a good level of protection against the introduction of the nematode into the pest risk assessment(PRA) area. It is also concluded that the whole PRA area is suitable for establishment ofD. destructor,but there is insufficient information to make a statement on the persistence of newly introducedpopulations in the entire PRA area. Impacts of this nematode on the quantity and quality of potato areconsidered negligible. The impact onflower bulb production in the EU is considered as very low.