Morphological and molecular characterization of two species of Neothada Khan, 1973 (Nematoda: Tylenchidae) from Iran, with notes on N. cancellata

Three species of the genus Neothada, including N. cancellata, N. hades and N. major, collected from the rhizosphere of mosses in Khuzestan, southwestern Iran, are redescribed and illustrated. Neothada hades and N. major are new records from Iran. Neothada hades has 14 longitudinal incisures excluding the lateral field, body length of 586 (505–674) µm, stylet 10.5 (10.0–10.8) µm in length bearing distinct basal knobs, and an elongated-conical tail 70.4 (65–74) µm long with a finely to bluntly rounded terminus. N. major possesses 18–20 longitudinal incisures excluding the lateral field, body length of 657 (600–728) µm, stylet 10.9 (10.3–11.7) µm long with basal swellings but not distinct knobs, and an elongated-conical tail 78.2 (70–83) µm long ending to a finely to bluntly rounded terminus. Molecular phylogenetic studies of the two species (N. hades and N. major) with 664 bp of D2-D3 expansion segments of 28 S rDNA revealed that they form a clade with N. cancellata.