Дополнительные данные по российским популяциям Helicotylenchus pseudorobustus (Steiner, 1914) Golden, 1956 и H. microlobus Perry, 1959 (Tylenchida: Hoplolaimidae)

During nematological surveys in 2023 and 2024, the species Helicotylenchus microlobus was found in the Rostov region and the Republic of Dagestan and the morphologically similar species H. pseudorobustus was found in the Pskov region. Information on Russian populations of these two species is very limited. In this work, morphological and morphometrical characterisations and the sequences of the COI gene of Russian populations of these species were obtained for the first time. The most useful morphological character for differentiating these species was the pattern of inner lateral line fusions on tail. Also, the COI gene is considered as a good marker to separate these two species.