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

Abstract

A new species, Oscheius microvilli n. sp., was found on Chongming Island (Shanghai, China). The new species is morphologically similar to the type strain of Oscheius myriophilus, but can be distinguished from it and other species of Oscheius on the basis of unique morphological characteristics of the bursa as well as male papillae. In this new species, the male bursal papillar formula is 2, 1, 3, 3 with everted tips in the first, fifth, and seventh pairs. The bursal rim is jagged, joins together anterior to the spicules, and is partially extended and decorated with microvilli. The spicules are incompletely separated, and the tail does not extend beyond the bursa. Phylogenetic trees of 18S rDNA and internal transcribed spacer indicate that the new species belongs to the insectivora group of the genus Oscheius; it is most closely related to O. myriophilus, and the two species can be distinguished on the basis of their different body length, morphological features of the bursa, and molecular data. The new species is facultatively associated with a bacterial strain of Serratia. The LC 50 of this novel nematode against Galleria mellonella was 69.1 dauer juveniles per milliliter after 48 hr of infection.

Description of Oscheius indicus n. sp. (Rhabditidae: Nematoda) from India

“…With the recent descriptions of O. microvilli (Zhou et al, 2017) and O. safricana (Serepa-Dlamini and Gray, 2018), at present, the number of valid species under the insectivora group of genus Oscheius is 30, whereas the dolichura group comprises of 14 species. Six species of the insectivora group, namely, O. carolinensis (Ye et al, 2010), O. niazii (Tabassum and Shahina, 2010), O. siddiqii (Tabassum and Shahina, 2010), O. amsactae , O. microvilli (Zhou et al, 2017) and O. safricana (Serepa-Dlamini and Gray, 2018) and one species in the dolichura group O. onirici (Torrini et al, 2015) are considered as entomopathogenic. The genus Heterorhabditidoides was proposed as a separate genus (Zhang et al, 2008) but it was later considered a junior synonym of Oscheius (Ye et al, 2010).…”

Morphological and Molecular Characterization of Oscheius saproxylicus sp. n. (Rhabditida, Rhabditidae) From Decaying Wood in Spain, With New Insights into the Phylogeny of the Genus and a Revision of its Taxonomy

“…Molecular data of Oscheius sensu lato species, many of them described during the last years, have been matter of analyses by several authors (Félix et al, 2001;Darby et al, 2011;Darsouei et al, 2014;Campos-Herrera et al, 2015;Torrini et al, 2015;Tabassum et al, 2016;Lima de Brida et al, 2017;Valizadeh et al, 2017;Zhou et al, 2017), resulting in the confirmation of the monophyly of the Insectivorus-and the Dolichura-group. Nonetheless, their nature as sister groups was not always corroborated (van Megen et al, 2009;Darsouei et al, 2014;Zhou et al, 2017).…”

The symbiotic bacteria Alcaligenes faecalis of the entomopathogenic nematodes Oscheius spp. exhibit potential biocontrol of plant‐ and entomopathogenic fungi

“…Besides the classically studied EPN species in the genera Steinernema and Heterorhabditis, several nematode species from genus Oscheius have been confirmed as EPNs (Ye et al, 2010;Pervez et al, 2013;Zhou et al, 2017). Similar to Steinernema and Heterorhabditis, Oscheius species are in association with several bacteria strains that belong to three classes; namely the betaproteobacteria (Alcaligenes), the gamma-proteobacteria (Enterobacter, Proteus, Providencia, Pseudomonas, Stenotrophomonas) and the Bacilli (Bacillus, Enterococcus, Lysinibacillus; Sangeetha et al, 2016).…”