Steinernema taiwanensis n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from Taiwan

Zootaxa ◽  
2018 ◽  
Vol 4434 (3) ◽  
pp. 466 ◽  
Author(s):  
CHING-TZU TSENG ◽  
ROGER F. HOU ◽  
LI-CHENG TANG

A new isolate of the entomopathogenic nematode, Steinernema taiwanensis n. sp., was isolated from soil in Pingtung County, Taiwan. This new species could be characterized and distinguished from other related species by its morphological characters, morphometrics, and phylogenetic analysis. The body length and distance from anterior end to nerve ring of infective juveniles is 1012 (983–1045) µm and 124 (120–127) µm, lateral field formula 2, 6, 7, 8, 2, and the tail length 90 (79–96) µm without dorsal constriction in tail region. The first generation males of S. taiwanensis n. sp. are characterized by spicule shape, smooth blade tip, 23 genital papillae (11 pairs and 1 single papilla), spicule length of 94 (89–99) µm and gubernaculum length of 68 (65–70) µm. Females from the first generation of S. taiwanensis n. sp. have no epiptygmata and a slightly developed post-anal swelling. Phylogenetic analysis of ITS and D2D3 regions of rDNA showed that S. taiwanensis n. sp. belongs to the Longicaudum-clade and comprises a monophyletic group with S. guangdongense and S. longicaudum. The new isolate is described as a novel species according to morphological and phylogenetic analyses. 

Nematology ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 653-669 ◽  
Author(s):  
Oleg Gorgadze ◽  
Elena Fanelli ◽  
Manana Lortkhipanidze ◽  
Alberto Troccoli ◽  
Medea Burjanadze ◽  
...  

Summary A new species of entomopathogenic nematode, Steinernema borjomiense n. sp., was isolated from the body of the host insect, Oryctes nasicornis (Coleoptera: Scarabaeidae), in Georgia, in the territory of Borjomi-Kharagauli. Morphological characters indicate that the new species is closely related to species of the feltiae-group. The infective juveniles are characterised by the following morphological characters: body length of 879 (777-989) μm, distance between the head and excretory pore = 72 (62-80) μm, pharynx length = 132 (122-142) μm, tail length = 70 (60-80) μm, ratio a = 26.3 (23.0-29.3), H% = 45 (40-51), D% = 54 (47-59), E% = 102 (95-115), and lateral fields consisting of seven ridges (eight incisures) at mid-body. Steinernema borjomiense n. sp. was molecularly characterised by sequencing three ribosomal regions (the ITS, the D2-D3 expansion domains and the 18S rRNA gene) and the mitochondrial COI gene. Phylogenetic analyses revealed that S. borjomiense n. sp. differs from all other known species of Steinernema and is a member of the monticolum-group.


Nematology ◽  
2012 ◽  
Vol 14 (6) ◽  
pp. 723-739 ◽  
Author(s):  
Juan Ma ◽  
Juan Ma ◽  
Shulong Chen ◽  
Juan Ma ◽  
Shulong Chen ◽  
...  

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 n. sp. 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-kraussei-oregonense’ group.


Nematology ◽  
2004 ◽  
Vol 6 (6) ◽  
pp. 819-838 ◽  
Author(s):  
Mutsuhiro Yoshida

AbstractA new entomopathogenic nematode, Steinernema litorale n. sp., was isolated from sandy soils in Cape Irago, Atsumi Peninsula, Aichi, Honshu Island, Japan. The new species is characterised by the following morphological characters: infective third-stage juvenile with a body length of 909 ± 42.1 (834–988) μm, distance from head to excretory pore of 61 ± 3.3 (54–69) μm, tail length of 83 ± 4.5 (72–91) μm, ratio E value of 0.73 (0.68–0.83) and lateral field with nine distinct lines; male tail with a mucron in both generations, spicule shape (moderately arcuate, heavy, spicule with elongated manubrium), spicule length of 75 ± 4.8 (67–89) μm and gubernaculum length of 53 ± 4.0 (44–64) μm in the first generation male; female vulva with a double-flapped epiptygma and a tail with a pointed tip in both generations, and ratio D value of 45.2 (33.3–56.8) in the first generation female. The new species was distinguished from the morphologically similar species, S. feltiae, S. thanhi, S. karii, S. scarabaei, S. kraussei, S. oregonense, S. loci and S. diaprepesi by RFLP profiles. Morphological and molecular studies indicated that S. litorale n. sp. was phenotypically most similar to S. feltiae. However, cross hybridisation tests demonstrated that the two species were reproductively isolated.


Zootaxa ◽  
2004 ◽  
Vol 460 (1) ◽  
pp. 1 ◽  
Author(s):  
ORESTE TRIGGIANI ◽  
ZDENEK MRÁ»EK ◽  
ALEX REID

Steinernema apuliae sp. n. has been found in soil samples collected along a saltpan border habitat in southern Italy characterized by a salted silt soil. This species belongs to the long-IJ nematode group represented by Steinernema glaseri (Steiner, 1929) and Steinernema arenarium (Artyukhovsky, 1967) among others. However, it differs from these taxa in some morphometric values such as V%, H%. Females possess asymmetrical, oblique slit vulva, slant vagina and small flap in the vulval opening. These characteristics are more distinct in second generation females which is different from most other steinernematids; the vulva position is behind the mid-body about 57% to 61% of the body length. First-generation females have a conical-like tip bearing 2 to 3 papilla-like protuberances. Male mucron is absent in both generations. Lightly brown spicules have bluntly pointed tip and elongated manubrium. Third-stage infective juveniles are on average over 1000 m long; the position of the excretory pore is posterior (D% 66) and the hyaline layer is less than half the tail length (H% 41 42). Lateral fields are formed by 8 equally distributed ridges. S. apuliae differs from S. glaseri and S. arenarium and is separated by PCR-RFLP analysis of the ITS region. There were no positive cross-breedings among these species.


Nematology ◽  
2011 ◽  
Vol 13 (5) ◽  
pp. 569-587 ◽  
Author(s):  
Nomakholwa F. Stokwe ◽  
Antoinette P. Malan ◽  
Khuong B. Nguyen ◽  
Rinus Knoetze ◽  
Louwrens Tiedt

Abstract During a survey for entomopathogenic nematodes in citrus orchards throughout South Africa, a new species of Steinernema was isolated from a citrus orchard on Rietkloof farm, near the town of Piketberg in the Western Cape Province, South Africa. The nematode was isolated from soil using the Galleria-baiting technique. Steinernema citrae n. sp. is characterised by the following morphological characters: third-stage infective juvenile with a body length of 754 (623-849) μm, distance from head to excretory pore of 56 (49-64) μm, tail length of 71 (63-81) μm, and ratio E value of 110 (85-132). The lateral pattern for the new species is 2, 7, 8, 6, 4, 2 and is not typical for the genus. Steinernema citrae n. sp. is closely related the feltiae-group. The body length of the IJ is close to that of S. texanum and S. weiseri, though it differs in body diam., the length of the pharynx and E%. The male of S. citrae n. sp. differs from S. feltiae in the length and shape of the spicule and body diam. Steinernema citrae n. sp. differs from all species in the feltiae-group in the morphology of the vulva, as it has a single flapped, low, epiptygma. It also differs from the most closely related species, S. feltiae, as there is no interbreeding between the two species. In addition, the new nematode differs from other species of the feltiae-group by characteristics of the ITS and D2D3 regions of its rDNA.


Nematology ◽  
2006 ◽  
Vol 8 (5) ◽  
pp. 681-690 ◽  
Author(s):  
Long K. Phan ◽  
Shuhei Takemoto ◽  
Kazuyoshi Futai

Abstract Steinernema ashiuense sp. n. was collected by a Galleria baiting method from grassland along the riverbank of the Yura river, near the Ashiu Research Forest Station of Kyoto University. The new species is characterised by an infective juvenile body length of 768 (720-800) μm, lateral field with five equally developed ridges (i.e., six lines or incisures), head smooth lacking horn-like structures, excretory pore located at level of middle of pharynx, hyaline portion short (ca one-third of tail length). Males have 50-65 μm long, broad, slightly yellowish spicules; spicule length / spicule width = 4 (3.5-4.4), and two subventral and one subdorsal pair of genital papillae in the postcloacal region. The analysis of ITS-rDNA sequence placed S. ashiuense sp. n. in the 'feltiae-kraussei-oregonense' group in the clade containing S. robustispiculum and S. monticolum. It can be distinguished from these species by morphological characters of the infective juveniles and males.


Nematology ◽  
2018 ◽  
Vol 20 (8) ◽  
pp. 781-794 ◽  
Author(s):  
Phougeishangbam Rolish Singh ◽  
Alliance Nyiragatare ◽  
Toon Janssen ◽  
Marjolein Couvreur ◽  
Wilfrida Decraemer ◽  
...  

Summary Pratylenchus rwandae n. sp., a root-lesion nematode associated with maize (Zea mays) from Rwanda, is described. This new species is characterised by females of medium to large size (469-600 μm) having an offset lip region with three annuli, stylet of 13-14.6 μm long with prominent rounded or anteriorly concave knobs, short to long pharyngeal gland overlap of 10.9-34.7 μm long, variable number of lateral lines (4-14) in different regions of the body, lateral field consisting of smooth bands, oval to slightly rounded spermatheca, vulva located at 75-80% of the total body length, post-vulval uterine sac (PUS) 20.3-26.5 μm long, tail subcylindrical to conoid with variation in tail tip shape from rounded to truncate or indented with generally smooth tip, and male unknown. The results of the phylogenetic analyses based on sequences of the D2-D3 expansion regions of 28S, partial 18S and ITS of rDNA and COI of mitochondrial DNA indicate that P. rwandae n. sp. is a species within the Penetrans group and appears as a sister species to a group comprising P. convallariae, P. dunensis, P. fallax, P. oleae, P. penetrans, P. pinguicaudatus, and three other unidentified species. A comparison of important morphological characters of the closely related Pratylenchus spp. is provided.


Zootaxa ◽  
2011 ◽  
Vol 2767 (1) ◽  
pp. 1 ◽  
Author(s):  
LIHONG QIU ◽  
JINGXIU ZHAO ◽  
ZHONGDAO WU ◽  
ZHIYUE LV ◽  
YI PANG

A new species of entomopathogenic nematode, herein described as Steinernema pui sp. n. was recovered from a soil sample collected from Xiao-jie town, Jing-hong city, Xi-shuang-ban-na district in Yunnan province, the People’s Republic of China in December 2002. Both morphological and molecular evidence show congruently that S. pui sp. n. belongs to the S. glaseri group. It can be separated from all described Steinernema species by a combination of morphological and morphometrical characters of adult and juvenile stages, including spicule and gubernaculum shape of the first generation males (spicule bearing an aperture on the tip and an irregular-shaped concave on ventral side of the lamina close to the tip; gubernaculum with a short needle-shaped cuneus); the tail and vulva shape of the first generation females (tail conoid and pointed with a mucron; vulva with a short double flapped epiptygma) and the body and tail length, distance from anterior end to excretory pore and to the base of pharynx of infective juveniles. The new species can also be distinguished from other Steinernema species by DNA sequences of either a partial 28S rDNA or the internal transcribed spacer (ITS) regions of rDNA, and from the closely related species S. longicaudum and S. guangdongense by cross-breeding tests.


Nematology ◽  
2014 ◽  
Vol 16 (7) ◽  
pp. 761-775 ◽  
Author(s):  
Ke Long Phan ◽  
Zdeněk Mráček ◽  
Vladimír Půža ◽  
Jiří Nermut ◽  
Andrea Jarošová

A new entomopathogenic nematode, Steinernema huense sp. n., belonging to the carpocapsae group, was recovered in Bach Ma National Park (Thua Thien Hue province) Vietnam. Steinernema huense sp. n. infective juveniles are characterised by short body length of 527 (444-571) μm, distance from anterior end to excretory pore of 43 (38-46) μm, anterior end to end of pharynx of 116 (103-129) μm; tail length of 50 (43-56) μm, D% = 37 (34-39) and E% = 85 (79-93), H% = 44 (39-52) and in having six ridges (i.e., seven lines) in the lateral field. For first generation males, the diagnostic characters include the spicule length of 67 (60-72) μm; D% = 48 (41-61); SW% = 195 (168-238) and GS% = 76 (68-81). Both generations possess a minute filamentous mucron, which can be rudimentary in the first generation, and 23 genital papillae. Spicules are finely curved, brownish and slender with a prominent rostrum. First generation females have a non-protruding, symmetrical vulva, with double flapped epiptygma. The tail of mature females is obese with a short conical tip (peg) lacking minute protuberances, and post-anal swelling not developed. The new species is further characterised by sequences of ITS and D2-D3 regions of the ribosomal DNA. According to molecular data, the symbiotic bacterium of S. huense sp. n. is closely related to Xenorhabdus stockiae.


Nematology ◽  
2014 ◽  
Vol 16 (4) ◽  
pp. 475-494 ◽  
Author(s):  
Isaiah Nthenga ◽  
Rinus Knoetze ◽  
Shaun Berry ◽  
Louwrens R. Tiedt ◽  
Antoinette P. Malan

A new species of entomopathogenic nematode, Steinernema sacchari n. sp., was isolated by trapping with the sugar cane borer, Eldana saccharina, from soil of a sugar cane field in the KwaZulu-Natal province of South Africa. The new species is morphologically characterised by the length of the infective juvenile (IJ) of 680 (630-722) μm, tail length of 64 (51-74) μm, ratio a = 19 (14-23), H% = 49 (43-57) and E% = 82 (70-109). The pattern of the lateral field of the IJ of the new species is 2, 5, 2 ridges (3, 6, 3 lines or incisures). The male of the first generation can be recognised by the long spicule of 83 (73-89) μm, gubernaculum of 61 (50-68) μm, D% = 67 (54-88) and GS% = 73 (66-81). The first generation male lacks a mucron, while the second generation male always has one. The first generation female can be recognised by the vulval lips not being raised, the possession of long double-flapped epiptygmata and the lack of a postanal swelling. Analysis of the ITS and D2D3 regions showed S. sacchari n. sp. to differ from all other Steinernema species and to belong to a new monophyletic group, the ‘Cameroonian’ clade, consisting of S. cameroonense, S. nyetense and S. sacchari n. sp. This group is closely related to the feltiae-kraussei-oregonense Clade III.


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