Pest categorisation of the non-EU phytoplasmas of tuber-forming Solanum spp.

Following a request from the European Commission, the EFSA Panel on Plant Health performed a pestcategorisation of four phytoplasmas of tuber-forming Solanum spp. known to occur only outside theEU or having a limited presence in the EU. The only tuber-forming species of Solanum reported to bephytoplasma infected is S. tuberosum. This opinion covers 'Candidatus Phytoplasma americanum','Ca. P. aurantifolia'-related strains (GD32; St_JO_10, 14, 17; PPT-SA; Rus-343F; PPT-GTO29, -GTO30,-SINTV; Potato Huayao Survey 2; Potato hair sprouts), 'Ca. P. fragariae'-related strains (YN-169, YN10G)and 'Ca. P. pruni'-related strains (Clover yellow edge; Potato purple top AKpot7, MT117, AKpot6;PPT-COAHP, -GTOP). Phytoplasmas can be detected by molecular methods and are efficientlytransmitted by vegetative propagation. Phytoplasmas are also transmitted in a persistent andpropagative manner by some insects belonging to families within Cicadomorpha, Fulgoromorpha andSternorrhyncha (order Hemiptera). No transovarial, pollen or seed transmission has been reported. Thereported natural host range of the phytoplasmas categorised here varies from restricted ('Ca. P.americanum', and 'Ca. P. fragariae'-related strains) to wide ('Ca. P. aurantifolia'-related strains and 'Ca.P. pruni'-related strains), thus increasing the possible entry pathways in the latter case. S. tuberosumis widely cultivated in the EU. All the categorised phytoplasmas can enter and spread through thetrade of host plants for planting, and by vectors. Establishment of these phytoplasmas is not expectedto be limited by EU environmental conditions. The introduction of these phytoplasmas in the EU wouldhave an economic impact. There are measures to reduce the risk of entry, establishment, spread andimpact. Uncertainties result from limited information on distribution, biology and epidemiology. All thephytoplasmas categorised here meet the criteria evaluated by EFSA to qualify as potential Unionquarantine pests, and they do not meet all the criteria to qualify as potential regulated non-quarantinepests, because they do not occur or are not known to be widespread in the EU.