Vector required: the case of the quarantine pine wilt nematode Bursaphelenchus xylophilus and the Monochamus longhorn beetles in Belgium

It is unclear if the destructive pine wilt disease (PWD) threatens Belgian conifer forests. From 2000 until today, FASFC (the Federal Agency for the Safety of the Food Chain) has monitored both entry and presence of the pathogen causing PWD, i.e. the quarantine nematode Bursaphelenchus xylophilus (PWN). This North American nematode has never been found throughout the whole of Belgium. However, the establishment and spread of the PWN, and its potential damage, are directly associated with the presence of its vectors, i.e. longhorn beetles of the genus Monochamus. Unfortunately, knowledge about the presence of these vectors in Belgium is lacking. For risk assessment of PWD for Belgium, it is essential to identify the various Monochamus species occurring in Belgium and map the geographic distribution and densities of their local populations. LUBIES and ILVO are gathering this information, by stimulating public participation and by establishing a network of attractant traps in pine forests and around import sites of timber throughout Belgium, in collaboration with FASFC. In the first year of our 3-year project we detected M. sartor and M. galloprovincialis adults, spread sparsely throughout Flanders. Further experiments and field monitoring in the next two years should indicate if these individuals are endemic or imported. Monitoring and action programs can then be established in the regions where Monochamus populations occur to allow for immediate action if PWN is introduced in the future.