Heterorhabditis pakistanensen. sp. (Nematoda: Heterorhabditidae) a new entomopathogenic nematode from Pakistan

2016 ◽  
Vol 91 (2) ◽  
pp. 222-235 ◽  
Author(s):  
F. Shahina ◽  
K.A. Tabassum ◽  
J. Salma ◽  
G. Mehreen ◽  
R. Knoetze

AbstractA new entomopathogenic nematode species ofHeterorhabditis, described asH. pakistanensen. sp., was isolated from soil samples around the roots of grass at Malir, Karachi, Sindh, Pakistan. The new species is characterized morphologically by features of males: body size 819 μm (720–1013 μm), D% ((distance from anterior end to excretory pore divided by pharynx length) × 100) 119 (110–126), SW% ((spicule length divided by anal body diameter) × 100) 156 (144–191), GS% ((gubernaculum length divided by spicule length) × 100) 58 (48–65) and variations in the number of bursal papillae of the terminal group: 8th and 9th papillae sometimes absent on both sides, sometimes eight papillae present on the right side whereas six papillae present on the left side. On the right side the arrangement of papillae is 1 + 2 + 3 + 2 whereas on the left side it is 1 + 2 + 3. The hermaphrodite has a prominent post-anal swelling and a conoid tail 82 μm (64–95 μm) long with a pointed terminus. Hermaphrodites ofH. pakistanensen. sp. can be distinguished from all species ofHeterorhabditisexceptH. downesiby having a mucronate tail. Infective juveniles have a medium-sized body (581 μm (558–624 μm)), long pharynx (117 μm (113–125 μm)), ensheathed tail (99 μm (95–110 μm)) and E% ((distance from anterior end to excretory pore divided by tail length) × 100) 100 (95–107). The new species can be distinguished from all species ofHeterorhabditisby the absence of the 7th, 8th and 9th bursal papillae.Heterorhabditis pakistanenseis further characterized by the internal transcribed spacer (ITS) and the D2D3 region of the 28S rDNA gene. The closest speciesH. indica, H. gerrardi, H. amazonensisandH. noenieputensisbeing separated by 9, 7, 66 and 15 bp, respectively, in the ITS region. Molecular phylogenetic trees based on sequences of ITS rDNA, D2D3 regions and the mitochondrial 12S rRNA gene support the description ofH. pakistanenseas a new species.

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 (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. 741-757 ◽  
Author(s):  
Tewodros Tamiru ◽  
Tewodros Tamiru ◽  
Lieven Waeyenberge ◽  
Tewodros Tamiru ◽  
Lieven Waeyenberge ◽  
...  

Three isolates (Dero-1, Dero-8 and Mosisa-1) of a new entomopathogenic nematode, S. ethiopiense sp. n., were isolated by baiting soil samples from the Mendi area, Western Wollega, Ethiopia, with last instar wax moth larvae Galleria mellonella. Infective juveniles of S. ethiopiense sp. n. have a body length of 898 (768-1010) μm, a maximum of eight identical ridges (i.e., nine lines) in the lateral field, excretory pore located at mid-pharynx, hyaline layer occupying approximately half of the tail and c′ = 3.2. First generation males lack a caudal mucron, whereas second generation males possess a short spine-like mucron. The spicules are slightly arcuate, golden-brown in colour and have an ellipsoid or oblong manubrium. First generation females lack a postanal swelling and have a minute protuberance on the tail tip whereas second generation females have a postanal swelling and protruding vulva. Based on the morphology, morphometrics and DNA analysis, the new species belongs to the glaseri group. The closest relative species is the afro-tropical S. karii recorded from Kenya. The BLAST analysis of the ITS region of the rDNA revealed a similarity of 93% with S. karii, supporting the validity of S. ethiopiense sp. n. as a new species. In the phylogenetic trees the new species groups together only with S. karii (bootstrap value of 100%), but is also separated from S. karii by a bootstrap value of 100% or 70%.


2009 ◽  
Vol 83 (4) ◽  
pp. 309-320 ◽  
Author(s):  
K.L. Plichta ◽  
S.A. Joyce ◽  
D. Clarke ◽  
N. Waterfield ◽  
S.P. Stock

AbstractA new entomopathogenic nematode species from Australia, Heterorhabditis gerrardi n. sp. (Nematoda: Heterorhabditidae) is described. Morphological and molecular studies together with cross-hybridization tests indicated that this nematode represents a new undescribed species, closely related to members in the ‘indica-group’. However, the new species can be distinguished from other species in this genus by a combination of several qualitative and quantitative morphological traits. Key diagnostic features include: body size and excretory pore position of the third-stage infective juveniles; male bursa with a reduction of bursal rays, usually affecting the terminal set of papillae, with symmetrical or asymmetrical loss of one or two pairs; vulva of hermaphrodites more anteriorly located than in other species in the indica-group (V% average: 43), with non-protruding or slightly protruding lips, and longer tail length (average: 106 μm). The new species can be further characterized by molecular traits of sequence data from the internal transcribed spacer (ITS) region of ribosomal DNA. Additionally, the bacterial symbiont of this new species, Photorhabdus asymbiotica Kingscliff strain, was phenotypically characterized and compared with other P. asymbiotica strains. The Kingscliff strain revealed many characters not present in other strains of this species. We hypothesize that the newly found traits may contribute to the maintenance of this mutualistic association of the bacterium with its nematode host.


Nematology ◽  
2007 ◽  
Vol 9 (3) ◽  
pp. 379-396 ◽  
Author(s):  
Robin Stuart ◽  
Ugur Gozel ◽  
Khuong Nguyen ◽  
Michael Rogers ◽  
Vanessa Andalo

AbstractSteinernema texanum n. sp. is characterised by morphometrics of the infective juvenile with body length = 756 μm, distance from anterior end to the excretory pore = 59 μm, tail = 73 μm, ratio a = 25, H% = 59 and E% = 81. The lateral field pattern of the new species is 2, 7, 2, and is typical for the species. The male of the first generation can be recognised by the spicule and the gubernaculum lengths and shapes, position of the excretory pore, D% = 67 and GS% = 75. The female can be recognised by the vulva with very low epiptygma and two wart-like structures anterior to the tail tip that are always present on the ventral side. Steinernema texanum n. sp. is characterised genetically by the sequence of the ITS region (sequence length = 956 bp, the length of ITS1 = 263 bp, ITS2 = 286 bp, composition of its sequence and by 18 autapomorphies) and by sequence of D2D3 regions (sequence length = 860 bp, its composition and 15 autapomorphies). Steinernema texanum n. sp. is closely related to species in the feltiae-group, which include S. akhursti, S. feltiae, S. hebeiense, S. jollieti, S. kraussei, S. kushidai, S. litorale, S. monticolum, S. oregonense, S. sangi, S. silvaticum and S. weiseri. Isolates of the new species were obtained using the Galleria-baiting technique from soil samples taken near Kingsville, Texas, USA.


Nematology ◽  
2006 ◽  
Vol 8 (2) ◽  
pp. 157-175 ◽  
Author(s):  
Antoinette Malan ◽  
Ugur Gozel ◽  
Khuong Nguyen

AbstractA new species of entomopathogenic nematode, Steinernema khoisanae n. sp. is described from South Africa. The new species is characterised by morphometrics of the infective juvenile with body length 1076 μm, narrow body diameter of 33 μm, excretory pore 94 μm from anterior end, tail 85 μm long, a = 33, D% = 68, H% = 57, and E% = 111. The lateral field pattern of the new species is 2, 7, 8, 6, 4 and 2. The male of the first generation can be recognised by the spicule and the gubernaculum shape, excretory pore located posteriorly near the end of the pharynx, D% = 88, and SW% = 199. The first generation female can be recognised by the non-protruding vulva and tail bearing a prominent mucron. Steinernema khoisanae n. sp. is characterised genetically by sequences of the internal transcribed spacers and D2/D3 regions of 28S ribosomal DNA, by composition of their sequences and by numerous unique, derived, nucleotide character states. Phylogenetic trees show that S. khoisanae n. sp. and other members of the S. glaseri-group form a monophyletic assemblage.


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.


2021 ◽  
Vol 8 (4) ◽  
pp. 55
Author(s):  
Feng Yu ◽  
Bo Liu ◽  
Shulei Chen ◽  
Ziwen Yi ◽  
Xianyong Liu ◽  
...  

A 5-year-old Mongolian mare (Equus caballus Linnaeus, 1758) was observed to have corneal opacity and excessive ocular discharge. An ophthalmic examination revealed a moving thread-like cylindrical worm in the anterior chamber of the right eye. The parasite was successfully removed surgically. The worm was observed under light microscopy and confirmed as Setaria digitata by 12S rRNA gene amplification and sequencing. Phylogenetic analysis demonstrated similarity with Setaria digitata in the National Center for Biotechnology Information (NCBI) GenBank database isolated from other Asian countries. This report is the first confirmed case of equine ocular setariasis by molecular diagnosis in China, which may indicate its presence in livestock and promote research on its epidemiology.


Author(s):  
Carlos Castaneda-Alvarez ◽  
Simona Prodan ◽  
Alan Zamorano ◽  
Ernesto San-Blas ◽  
Erwin Aballay

Xenorhabdus is a symbiotic group of bacteria associated with entomopathogenic nematodes of the family Steinernematidae. Although the described Steirnernema species list is extensive, not all their symbiotic bacteria have been identified. One single motile, Gram-negative and non-spore-forming rod-shaped symbiotic bacterium, strain VLST, was isolated from the entomopathogenic nematode Steinernema unicornum. Analyses of the 16S rRNA gene determined that the VLST isolate belongs to the genus Xenorhabdus , and its closest related species is Xenorhabdus szentirmaii DSM 16338T (98.2 %). Deeper analyses using the whole genome for phylogenetic reconstruction indicate that VLST exhibits a unique clade in the genus. Genomic comparisons considering digital DNA–DNA hybridization (dDDH) values confirms this result, showing that the VLST values are distant enough from the 70 % threshold suggested for new species, sharing 30.7, 30.5 and 30.3 % dDDH with Xenorhabdus khoisanae MCB, Xenorhabdus koppenhoeferi DSM 18168T and Xenorhabdus miraniensis DSM 18168T, respectively, as the closest species. Detailed physiological, biochemical and chemotaxonomic tests of the VLST isolate reveal consistent differences from previously described Xenorhabdus species. Phylogenetic, physiological, biochemical and chemotaxonomic approaches show that VLST represents a new species of the genus Xenorhabdus , for which the name Xenorhabdus lircayensis sp. nov. (type strain VLST=CCCT 20.04T=DSM 111583T) is proposed.


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.


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