Steinernema xinbinense Ma et al. 2012
Summary
– During a survey for entomopathogenic nematodes in northern China, a new species of Steinernema was
isolated from soil samples collected from Xinbin county, Liaoning province. This nematode was
obtained by the insect-baiting technique using last instar larvae of Galleria
mellonella. It is described herein as S. xinbinense. The nematode
can be separated from other described species of the group by morphological and
morphometric characteristics of the different stages and by characterisation
and phylogeny of DNA sequences of the D2D3 domain of the LSU or ITS regions of
rDNA. This new species is characterised by the following morphological characters:
infective third-stage juvenile with a body length of 694 (635-744) μm, distance from head to excretory
pore of 51 (46-53) μm, tail
length of 73 (61-81) μm, E = 71 (65-78)%, presence of eight
unevenly spaced and developed ridges in middle lateral field (i.e., nine
lines). First generation male with well curved, yellowish spicules 56 (49-62) μm long and gubernaculum 35 (30-41) μm long, small mucron mostly present,
first generation female with protruding vulva, tail conical with one or two
small mucrons and D = 45
(41- 50)%.
Cross hybridisation tests with S. tielingense, S. kraussei, S.
feltiae and S. hebeiense showed that this species was reproductively
isolated. The analyses of ITS-rDNA and D2D3 sequence confirm that the studied
nematode isolate is a valid new species belonging to the feltiae group.