Scientific Opinion on comments provided by Portugal on the phytosanitary risk associated with Pinus pinea for the spread of pine wood nematode

Following a request from European Commission, the PLH Panel examined the comments of the Portuguese plant health authorities on a previous EFSA opinion with regard to pine wood nematode (PWN) and Pinus pinea and a report on PWN surveys in Portugal. Regarding the comment, based on behavioural responses of PWN to CO2 and to ß-myrcene, that Monochamus galloprovincialis can feed on P. pinea without implying PWN infestation, the Panel noted the uncertainties on how chemical attraction influences the exit of PWN from the vector. The Panel agreed that P. pinea is not a preferred breeding host of M. galloprovincialis, but it noted the evidence from Italy of breeding of M. galloprovincialis in fallen woods of P. pinea, suggesting P. pinea to be an occasional host. The Panel agreed that, although pathogenicity of PWN has been recorded on P. pinea in inoculation experiments on small plants, this does not necessarily relate to pathogenicity on larger trees in the field. The additional information on Portuguese PWN surveys is not sufficient to conclude that P. pinea is resistant to PWN. The Panel also noted that asymptomatic infestations by PWN are well known in other areas, and pine species considered tolerant to PWN could still maintain it at low levels in restricted parts of a tree. The Panel concluded that there is high uncertainty concerning the classification of the risk of spread of PWN with plants and wood of P. pinea, owing to the scarcity of information on the interaction of M. galloprovincialis, PWN and P. pinea, as well as on the field resistance of P. pinea to PWN. Owing to high uncertainty related to the host potential of P. pinea, more studies on the transmission of PWN at feeding wounds and on its survival in trees and wood of P. pinea are needed.