Pine wilt disease (PWD) is perhaps the most serious threat to pine forests worldwide. The causative agent of PWD, the pinewood nematode (PWN), engages in a symbiotic partnership with its insect vector, the Monochamus beetle, as well as associated bacteria and ophiostomatoid fungi, in order to successfully infect and kill its host pine tree. This review focuses on the interspecific communication between PWN and its associated partners, and the potential role of this communication in promoting pathogenicity and invasiveness of PWN. We describe the chemical and molecular signals positively influencing the survival, reproduction, and spread of PWN. Knowledge of these signals could potentially be used to interfere with the proliferation and dispersal of PWN.