Ruehmaphelenchus taedae n. sp., isolated from Loblolly pine logs (Pinus taedae L.) from the USA, is described and figured. It is characterised by a relatively slim body (a = 42 and 43 for males and females, respectively), three lines in the lateral field, male spicules relatively small (12-18 mu m) with high and dorsally bent condylus and weakly developed rostrum, bursal flap absent, short tail possessing a long terminal spike ending in a bluntly rounded tip and 8.7-13.3 mu m long, vulva positioned at ca 83% of body length, vulval flap absent, vulval lips slightly protruding, post-vulval uterine branch extending for less than half of vulva to anus distance, and female tail conoid, ca 3-4 anal body diam. long, with 13.7-18.5 mu m terminal projection. The new species can be separated from all other species of the genus by the male tail possessing a long terminal spike and the more anterior excretory pore. Detailed phylogenetic analysis based on 28S D2-D3 region sequences confirmed the status of this nematode as a new species.