Description of Deladenus uljinensis n. sp., and additional DNA barcode data for Deladenus posteroporus (Nematoda: Neotylenchidae) from Korea

A new species of the genus Deladenus isolated from a dead red pine tree was characterized using morphometric and molecular DNA data. Deladenus uljinensis n. sp. is characterized by its lateral fields with six to seven lines, pharyngeal corpus without a distinct median bulb and lacking a chamber, esophageal-intestinal junction located immediately behind the nerve ring, hemizonid located posterior to nerve ring, excretory pore opening within the contour of hemizonid or just at the base of hemizonid, vulva with no lateral vulval flaps, post-uterine sac rudimentary or absent, vulva-anus distance ca. equal to tail length, tail conoid, gradually tapering to a broadly rounded terminus, and slender spicules, 18.5–21.5 μm long. The new species was compared with morphologically close species including D. gilanica, D. brevis, D. pakistanensis, D. oryzae, D. uteropinusus, D. aridus, and D. durus. Additionally, D. posteroporus was also characterized and the population represents the first record of the species outside its type locality. The phylogenetic relationships among species were reconstructed using 18S-rRNA, 28S-rRNA and COI gene sequences. Inferences from the more informative 28S-rRNA gene suggest that D. uljinensis n. sp. is a sister species to the morphologically close D. gilanica.