A new entomopathogenic nematode, Steinernema tielingense n. sp (Rhabditida: Steinernematidae), from north China

A new species of Steinernema was isolated from shrub soils in Liaoning province during a survey for entomopathogenic nematodes in north China. This nematode was obtained by the insect-baiting technique using last instar larvae of Galleria mellonella (Lepidoptera: Pyralidae). This new species is described herein as S. tielingense n. sp. It belongs to the 'feltiae-kraussei-oregonense' group and is characterised by infective third-stage juvenile (IJ) with a body length of 915 (824-979) mu m, distance from head to excretory pore of 69 (64-73) mu m, tail length of 81 (74-85) mu m, ratio E = 88 (85-94)%, lateral field with eight ridges at mid-body, first generation male spicule 88 (79-98) mu m and gubernaculum 61 (49-70) mu m long, and first generation female with a vulval protrusion and ratio D = 41 (32-49)%. The new species distinctly differs from the related species S. kraussei, S. silvaticum, S. oregonense and S. cholashanense in the different number of ridges in the lateral fields and hyaline tail length as % of total tail length of 11 and male body length and distance from head to excretory pore. Cross hybridisation tests showed that these species were reproductively isolated. The sequences analyses of the internal transcribed spacers (ITS) and D2-D3 regions of the ribosomal DNA confirm this to be a new species.