The pine wood nematode and its local vectors in the mediterranean basin

Abstract

The pine wood nematode Bursaphelenchus xylophilus is the causal agent of pine wilt disease, being one of the most important threats to conifer forests in the EU. This exotic nematode was detected in Southern Portugal in 1999, and has since been introduced into neighbouring Spain. In Iberia, the nematode affects mainly maritime pine, Pinus pinaster, but also black pine Pinus nigra, being its single vector the pine sawyer Monochamus galloprovincialis. In general, the entire Mediterranean basin presents a high risk to pine wilt disease, due to favourable climatic environments with prolonged periods of hot and dry conditions, the existence of forests with susceptible pine species such as maritime, black and scots pine, and the presence of multiple potential vectors of native species of the Monochamus genus, sharing similar biologies and life-histories. Besides M. galloprovincialis, special attention should be given to Monochamus sutor, a similar species with widespread distribution in Europe, and already found to be a key-vector of the related native nematode, Bursaphelenchus mucronatus. This chapter summarises the latest research on the ecology of European Monochamus and their interaction with Bursaphelenchus nematodes, with a natural emphasis on the PWN’s vector, M. galloprovincialis. Also discussed are the options available to manage and control this tree health problem, which is currently responsible for significant pine mortality in Iberia’s affected regions, and constitutes an immediate threat to pine ecosystems all over Europe, but particularly in the Mediterranean basin.