Description of Ruehmaphelenchus quercophilus n. sp. (Nematoda: Aphelenchoididae) from dying oak, Quercus robur, in Poland

Ruehmaphelenchus quercophilus n. sp., isolated from a dying oak, Quercus robur , in the State Forests, Łopuchowko District, Poland, is described and figured. It is characterised by three lateral lines, relatively stout body, excretory pore posterior to nerve ring, five caudal papillae, spicules relatively small (12-14  μ m) with weakly developed condylus and rostrum, bursa absent, vulva positioned at ca 78% of body length, vulval flap absent, post-uterine branch extending for slightly over half of vulva to anus distance, and conoid tail with a bend at the distal end forming a terminal projection 10-14  μ m long. The new species is very similar to four other described species, namely R. formosanus , R. juliae , R. thailandae , and R. sirisus . Detailed phylogenetic analysis based on 18S, 28S D2-D3 and ITS sequences has confirmed the status of this nematode as a new species.