Impact of the pinewood nematode on naturally-emitted volatiles and scCO2 extracts from Pinus pinaster branches: a comparison with P. pinea

[Display omitted] •Moisture content of PWN-infected P. pinaster is related to the PWN number.•Limonene was naturally-emitted by all P. pinea and some infected P. pinaster branches.•Abietadiene was identified in some scCO2 extracts of PWN-infected branches.•All extracts were able to inhibit the acetylcholinesterase enzyme.•All extracts revealed no effects on PWN-mortality. In Portugal, the pinewood nematode (PWN), Bursaphelenchus xylophilus, has been affecting Pinus pinaster, leading to economic and ecological losses, while P. pinea is a less susceptible species. The main goal of this study was to assess volatile composition of PWN-infected P. pinaster, and both non-infected P. pinaster and P. pinea branches, by using supercritical carbon dioxide extraction compared with solid-phase microextraction (SPME). Volatile profile was associated to nematodes number, which was related to moisture content. Extracts effects on acetylcholinesterase (AChE) inhibitory activity, and in vitro PWN-mortality were analyzed. Limonene was the main volatile naturally-emitted by P. pinea and by some PWN-infected P. pinaster samples. Abietadiene was identified in some PWN-infected P. pinaster extracts, which may be due to a tree defensive response. Supercritical CO2 extracted ∼5–20 heavier compounds than those identified by the SPME-GC/MS technique. Extracts revealed AChE inhibition, corresponding to a possible insecticidal/nematicidal effect. However, no PWN-mortality was found.