n. sp. (Tylenchomorpha: Aphelenchoididae) from South Africa, a morphological and molecular phylogenetic study, with an update to the diagnostics of the genus.

A newly recovered population of the genus from a dead maritime pine wood sample in Potchefstroom, South Africa, representing a new species, named n. sp., is herein described and illustrated based on morphological and molecular data. The new species is mainly characterized by the following: 750-987 µm long females; a cephalic region with no disc and six cephalic lobs not divided by ribs; a 10.0-12.5 µm long stylet; four incisures in the lateral field; secretory-excretory pore (SE-pore) at slightly posterior to the nerve ring; vulva with a well-developed anterior flap, vagina with two well-developed sclerotized pieces; post-vulval uterine sac (PUS) 63-125 µm long; tail conical, 30-44 µm long, ventrally curved with a subventral stalk in terminus, lacking tubercles, with six to nine small projections at the tip in scanning electron microscopy (SEM); and rare males with 17 μm long spicules. The new species was morphologically compared to those species of the genus with a stalk in tail terminus, lacking tubercles, a vulval flap and four incisures in the lateral field viz., , , , , , and . Phylogenetically, the new species was placed into the major clade using partial large subunit ribosomal DNA (LSU rDNA D2-D3) sequences. An overall literature review corroborated the presence of the stalk (currently with two main groups) at the tail end is the main characteristic trait delimiting the genus. A compendium based on the characters of the stalk, presence/absence of a vulval flap in females and number of the lateral lines was also established.