Steinernema sandneri n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Poland.

Waldemar Kazimierczak,Magdalena Lis,Marcin Skowronek,Adrian Wiater,Ewa Sajnaga,Kamila Rachwał

doi:10.21307/jofnem-2021-051

Abstract

A new species of entomopathogenic nematodes, Steinernema sandneri n. sp., was recovered by baiting from Poland. Its morphological traits indicate that the new species is a member of the feltiae-kraussei group. A body length of 843 (708–965) μm, a more anterior position of excretory pore (56 μm), and the lower D% value (40 vs > 46) discriminate this species from most of the other group members. The first-generation males of S. sandneri n. sp. can be distinguished from the other clade members by a 60 μm long spicule, a relatively long gubernaculum (GS% = 79), and the position of the excretory pore (80 μm). Phylogenetic analysis of the ITS rDNA, D2D3 of 28 S rDNA, and cox1 sequences confirmed that S. sandneri n. sp. is a new species of the feltiae-kraussei group, closely related to S. kraussei and S. silvaticum.

Highlights

Entomopathogenic nematodes of the families Stei nernematidae Travassos, 1927 and Heterorhabditidae Poinar, 1976 are obligate lethal pathogens of insects with a worldwide distribution (Adams et al, 2007; Hominicki, 2002; Spiridonov and Subbotin, 2016)
15 of the ~100 recognized species of Steinernema have been recorded in Europe so far, including 5 feltiae-kraussei represen tatives: S. kraussei, S. feltiae, S. weiseri, S. silvaticum, and S. ichnusae
Sequence analysis of internal transcribed spacer (ITS) rDNA and D2D3 expansion segment of 28 S rDNA have been proved useful for estimation of EPN species, by supporting mor phological data (Nadler et al, 2006; Nguyen, 2007a, b; Stock et al, 2001)

Summary

Introduction

Entomopathogenic nematodes of the families Stei nernematidae Travassos, 1927 and Heterorhabditidae Poinar, 1976 are obligate lethal pathogens of insects with a worldwide distribution (Adams et al, 2007; Hominicki, 2002; Spiridonov and Subbotin, 2016). Nematodes of the last group can be characterized by a body length of ≤ 1,000 μ m, an elliptical bacterial pouch, and 6-8 lateral fields in infective juveniles (IJs) At present, this group includes Steinernema kraussei Steiner, 1923; S. feltiae Filipjev, 1934; S. kushidai Mamiya, 1988; S. oregonense Liu and Berry, 1996; S. sangi Phan et al, 2001; S. weiseri Mráček et al, 2003; S. jollieti Spiridonov et al, 2004a, b; S. litorale Yoshida, 2004; S. akhursti Qiu et al, 2005; S. silvaticum Sturhan et al, 2005; S. hebeiense Chen et al, 2006; S. cholashanense Nguyen et al, 2008; S. puntauvense Uribe-Lorió et al, 2007; S. texanum Nguyen et al, 2007; S. ichnusae Tarasco et al, 2008; S. xueshanense Mráček et al, 2009; S. citrae Stokwe et al, 2011; S. tielingense Ma et al, 2012a, b; S. xinbinense Ma et al, 2012a, b, and S. nguyeni. Etymology: The species is named after Henryk Sandner, zoologist, a pioneer of entomonematology in Poland, Righteous Among the Nations

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