Pest categorisation of Nacobbus aberrans

European Union, pest risk, plant health, plant pest, quarantine, false root-knot nematode
First published in the EFSA Journal
11 aprile 2018
21 marzo 2018
Scientific Opinion


The Panel on Plant Health performed a pest categorisation of Nacobbus aberrans (Nematoda: Pratylenchidae), the false root-knot nematode, for the EU. The nematode was originally described from the American continent. Due to differences in host range as well as molecular variability among populations, N. aberrans should be regarded as a species complex (N. aberrans sensu lato). All populations belonging to this species complex are pests of important host plants in the EU. N. aberrans had been detected indoors in the EU in the 1950s and 1960s but is no longer reported to be present in the EU. It is regulated by Council Directive 2000/29/EC, listed in Annex IAI as N. aberrans (Thorne) Thorne and Allen. Species within the N. aberrans complex are endoparasitic with migratory and sedentary stages. They are highly polyphagous attacking many plant species. They are also found in soil where they can survive dry conditions and freezing temperatures. Plants for planting and soil are potential pathways for this nematode. Climatic conditions in the EU are similar to those found in the countries where the pest is present. Hosts of the nematode from which high-yield losses have been reported include potato, sugar beet, tomato and beans. The nematode only moves short distances (around 1m) but may be spread with plants and soil moving activities. Measures are available to inhibit EU entry via potatoes and soil as such but not all host plants are covered by current legislation. Entry of the nematode with plants and soil attached to plants for planting that are not regulated is therefore possible. N. aberrans does satisfy all the criteria that are within the remit of EFSA to assess to be regarded as a Union quarantine pest.

Panel members at the time of adoption

Claude Bragard, David Caffier, Thierry Candresse, Elisavet Chatzivassiliou, Katharina Dehnen-Schmutz, Gianni Gilioli, Jean-Claude Grégoire, Josep Anton Jaques Miret, Michael Jeger, Alan MacLeod, Maria Navajas Navarro, Björn Niere, Stephen Parnell, Roel Potting, Trond Rafoss, Vittorio Rossi, Gregor Urek, Ariena Van Bruggen, Wopke Van der Werf, Jonathan West and Stephan Winter.
Panel on Plant Health
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EFSA Journal 2018;16(4):5249
Question Number
On request from
European Commission