Steinernema goweni n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Zulia State, Venezuela

Abstract

A nematode from the genus Steinernema was isolated in Zulia state (North-western, Venezuela). Morphological, morphometric and molecular studies indicated that this nematode belongs to the "bicornutum" group and is described herein as Steinernema goweni n. sp. Steinernema goweni n. sp. is characterised by morphometrics of its infective juveniles, with body length 640 (531-719) µm, pharynx length of 119 (109-126) µm, tail of 67 (59-89) µm, c ratio = 9 (6-11) and E% = 77 (48-94). First generation male specimens can be recognised by the shape and size of spicules (55 (50-57) µm long) and gubernaculum (35 (30-40) µm long), and %D value 42 (28-59), which is at the lower limit within the "bicornutum" group. The number of genital papillae in males is also distinctive for S. goweni n. sp. presenting up to 27 (13 pairs + 1) papillae in 15% of specimens. The phasmids can be seen in scanning electron microscopy in all stages, characters not previously reported within the "bicornutum" group. Phylogenetic analyses of the "bicornutum" group based on both ITS and D2D3 regions showed a clear separation of S. goweni n. sp. from the other species. In both analyses S. goweni n. sp. formed a strongly supported group of American species.

First Report and Comparative Study of Steinernema surkhetense (Rhabditida: Steinernematidae) and its Symbiont Bacteria from Subcontinental India

“…The DNA extraction and amplification of the ITS and D2-D3 regions of the rRNA were performed according to San-Blas et al (2016). For the COI mtDNA region, the PCR protocol included denaturation at 948C for 3 min, followed by 37 cycles of 948C for 30 sec, 508C for 30 sec, and 728C for 45 sec, followed by a final extension at 728C for 7 min.…”

“…Genomic DNA extraction, amplification, and sequencing: For phylogenetic analysis, three molecular markers were used: internal transcribed spacer (ITS) regions of rDNA; partial sequence of 28S, D2-D3 domain; and mitochondrial gene encoding cytochrome C oxidase subunit I (COI). The DNA extraction and amplification of the ITS and D2-D3 regions of the rRNA were performed according to San-Blas et al (2016). For the COI mtDNA region, the PCR protocol included denaturation at 948C for 3 min, followed by 37 cycles of 948C for 30 sec, 508C for 30 sec, and 728C for 45 sec, followed by a final extension at 728C for 7 min.…”

Entomopathogenic nematology in Latin America: A brief history, current research and future prospects

“…In Brazil, the species currently known as Steinernema glaseri was isolated and characterized (Travassos, 1927). To date, 16 out of 117 currently described species (12 Steinernema and 4 Heterorhabditis) (Shapiro-Ilan et al, 2018) were first discovered in Latin America, including Steinernema colombiense (López- Nuñez et al, 2008), S. goweni (San-Blas et al, 2016), S. papillatum (San-Blas et al, 2015a), S. puntauvense (Uribe-Lorío et al, 2007), Heterorhabditis atacamensis (Edgington et al, 2011) and H. sonorensis (Stock et al, 2009) being considered endemic (table 1). Additional isolates and species remain undescribed.…”

Oscheius microvilli n. sp. (Nematoda: Rhabditidae): A Facultatively Pathogenic Nematode from Chongming Island, China

“…Entomopathogenic nematodes (EPNs) and other parasitic nematodes are lethal parasites against insects and slugs, and they have been applied as biological approaches to pest management (Poinar, 1979;Wilson et al, 1993;Hazir et al, 2003;Nguyen et al, 2008;Stock et al, 2009;Tamura et al, 2011;Kanzaki et al, 2013;Phan et al, 2014;San-Blas et al, 2016). EPNs in particular have been utilized to control a range of pests for more than half a century in U.S. and European countries, where they have been found to be particularly effective against soil-dwelling insects, plant-boring insects, and unknown pests (Poinar, 1979;Ehlers, 1996;Berry et al, 1997;Hazir, 2003).…”