Steinernema xueshanense
Mracek, Qi-Zhi
& Nguyen, 2009
During a random EPN survey in the
northern part of the Yunnan province
(southeastern Tibet, Dequen district,
town of Dequen)
in 2005, soil samples containing an unknown EPN species were collected. The new
species is described as Steinernema xueshannense named after the Xue Shan Mts. a mountain range
between Yunnan and Tibet where the nematode was
collected. The isolate is a new species belonging to the Steinernema
feltiae group. S.
xueshanense is characterized
by male, female of both generations and infective juveniles (IJ). IJ lateral
field with eight ridges, submarginal pair less distinct, formula 2, 7, 8, 7, 6,
4, 2, Hyaline portion occupies approximately one half of tail length.
Second-generation males with distinct mucron and moderately curved spicules. Females
wuth a characteristic cone on the tail. Infective juveniles of S.
xueshanense differ
from S. akhursti,
S. cholashanense S. kraussei, S. oregonense
by different number of
ridges in lateral fields. Species which have same number of eight lateral
ridges, such as S. silvaticum, S. thanhi, S. weiseri differs from S. xueshanense
by less prominent sublateral pair whereas those species have all ridges equally
spaced and prominent. Only S. feltiae possess the same pattern of ridges as S. xueshanense,
but this species differ by shape of spicules with oblongate manubrium. The
description of S. sangi gives only a few characters to compare this species with S.
xueshanense. The
exception is the excretory pore position of IJs which is at 40% of pharynx
length whereas in other species of this group, including S. xueshanense,
it is situated approximately at 50%. Cross-breedings, sequences of ITS and
D2/D3 regions of the ribosomal DNA confirmed the new species identity.