Sychnotylenchus kulinichi sp. n. (Nematoda: Anguinoidea) from the Primorsky Krai of Russia with a tabular key to the genus Sychnotylenchus Rühm, 1956

What is it about?

A new species of the genus Sychnotylenchus Ruhm, 1956, S. kulinchi sp. n. inhabiting the bark beetle galleries of Pityogenes chalcographus in Pinus koraiensis was found in the Primorsky Krai of Russia. The new species differs morphologically from the closely related species S. yasinskii and S. mayor in having shorter body length and from S. sparnugus in having a greater value of the ratio between spicule length and tail length. Phylogenetic analysis of the partial 18S rRNA, D2-D3 expansion segments of the 28S rRNA, the ITS rRNA and COI gene sequences showed that Russian S. kulinichi sp. n. population grouped with population from Israel which is conspecific of S. kulinichi sp. n. Phylogenetic analyses aiming to clarify the controversial taxonomic status of Neoditylenchus and Sychnotylenchus species, indicated that testing of alternative topologies for the 18S rRNA, D2-D3 of 28S rRNA and ITS rRNA gene trees and datasets using ML method did not justify the validity of the genus Neoditylenchus, which should be considered a junior synonym of Sychnotylenchus as proposed by Fortuner and Maggenti (1987). Molecular phylogeny showed close relationships of Sychnotylenchus with plant parasitic nematodes from the genera Ficotylus, Orrina and Pterotylenchus, and the insect-associated Neomisticius. A polytomous key listing 24 morphological characters for the identification of 33 species of the Sychnotylenchus along with a table listing associated bark beetle species are provided.

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