Report of the first finding of Bursaphelenchus poligraphi and B. paraleoni in Italy

Bark beetles play an important ecological role in forest ecosystems, but under certain conditions, they can become a serious phytosanitary threat to host plants. This risk increases in the presence of environmental stress factors linked to climate change, such as heavy snowfall, strong winds, and prolonged drought periods. This study focused on weakened or declining stands of Norway spruce (Picea abies) in the Apennines, specifically in the areas of Abetone (Tuscany) and Montedimezzo (Molise), affected by infestations of the beetle Polygraphus poligraphus L. (Coleoptera: Curculionidae, Scolytinae). During monitoring activities carried out in 2024, samples of wood, bark, and adult beetles were collected from infested trees. To investigate the possible presence of associated nematodes, the wood and bark samples were processed using the Oostenbrink dish method, while the adult insects were examined through direct observation under a stereomicroscope. The analyses led to the identification of two nematode species never before reported in Italy: Bursaphelenchus poligraphi, isolated from both wood and adult beetles — previously known only in France, Germany, Romania, and Slovakia — and Bursaphelenchus paraleoni, found in wood samples from Molise, until now, only been reported in China, where it was intercepted in wood imported from the United States.