This work was partially supported by the Portuguese national project ‘O nema´ode-da-madeira-do-pinheiro (NMP), Bursaphelenchus xylophilus’ (Fundo Florestal Permanente) and by research grants to FP (SFRH/BPD/44637/2008) and BA (SFRH/BPD/73108/2010) from the Portuguese Foundation for Science and Technology (FCT). MM was partially supported by the EC 7th Framework project REPHRAME (KBBE.2010.1.4-09, ‘Analysis of the potential of the pine wood nematode (Bursaphelenchus xylophilus) to spread, survive and cause pine wilt in European coniferous forests in support of EU plant health policy’). The Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP) is an Associate Laboratory of the Portuguese Ministry of Science, Technology and Higher Education and is partially supported by FCT