Steinernema citrae n. sp. (Rhabditida: Steinernematidae), a new entomopathogenic nematode from South Africa

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 (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 ◽  
2008 ◽  
Vol 10 (3) ◽  
pp. 381-396 ◽  
Author(s):  
Louwrence Tiedt ◽  
Khuong Nguyen ◽  
Jeanne de Waal ◽  
Antoinette Malan

AbstractDuring a survey for entomopathogenic nematodes in the Western Cape Province of South Africa, a new species in the genus Heterorhabditis was collected from a peach orchard. The nematode was trapped by the insect-baiting technique using last instar larvae of Galleria mellonella. The infective juvenile of the new species differs from the morphologically closest species, H. marelatus, in shorter body length 600 (550-676) vs 685 (588-700) μm and the shorter tail of 93 (86-108) vs 107 (99-117) μm. It differs from all other species in the vulva pattern of hermaphroditic female. The genital papillae of the male H. safricana n. sp. are typical for species in the megidis-group (three papillae in terminal group). The average length of the gubernaculum is longer than that of all other species (24 vs 19-23 μm) and the gubernaculum length as a percentage of spicule length (53.9) is less than that of H. mexicana (56), similar to that of H. floridensis (53.8), but larger than that of all others (51 or less). For molecular characterisation, the species closest to H. safricana n. sp. is H. marelatus. The length of the ITS rDNA sequence of the new species is characterised by 995 base pairs, identical to that of H. marelatus, but differs from this species by 25 aligned positions, seven of which are unambiguous autapomorphies. Phylogenetic trees show further evidence of a separate species status for H. safricana n. sp.


Zootaxa ◽  
2020 ◽  
Vol 4823 (1) ◽  
pp. 1-64
Author(s):  
HOLGER E. DOMBROW ◽  
JONATHAN F. COLVILLE

Fifteen years after establishing the genus Beckhoplia Dombrow, 2005 a large amount of new material collected has warranted a critical review of the established species and a revision of the genus. From this process, we describe fifteen new species from the Northern Cape Province and Western Cape Province of the Republic of South Africa: Beckhoplia bicolor Dombrow, new species, B. caliginosa Dombrow, new species, B. castanea Dombrow, new species, B. dolichiocnemis Dombrow, new species, B. elkeae Dombrow, new species, B. fusca Dombrow, new species, B. gifbergensis Dombrow, new species, B. nigra Dombrow, new species, B. nigrofasciata Dombrow, new species, B. nigrosetosa Dombrow, new species, B. pallidibrunnea Dombrow, new species, B. pulchra Dombrow, new species, B. pumilla Dombrow, new species, B. setosa Dombrow, new species and B. suturalis Dombrow, new species. Two cryptic species complexes within the species B. colvillei Dombrow, 2005 and B. occidentalis Dombrow, 2005 were detected. A revised key of the genus and observations about its biogeography are given. Important details of the morphological characters of the body and the parameres of the species are illustrated and their distributions are mapped. We also provide habitat and host plant information. 


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.


Nematology ◽  
2014 ◽  
Vol 16 (7) ◽  
pp. 821-836 ◽  
Author(s):  
Shahina Fayyaz ◽  
Xun Yan ◽  
Lihong Qiu ◽  
Richou Han ◽  
Mehreen Gulsher ◽  
...  

A new species of Steinernema is described herein as S. bifurcatum n. sp. It is characterised by the presence of a male gubernaculum that is bifurcate at both proximal and distal ends, a key diagnostic feature. Steinernema bifurcatum n. sp. belongs to the bicornutum group by having two horn-like structures on the labial region of the infective juvenile (IJ). It can be recognised by IJ body diam. = 22 (20-24) μm, pharynx = 114 (102-134) μm, ratio a = 24 (22-25) and D% = 39.7 (33-47). The new species can be further recognised by the male characters of D% = 48 (42-58), and genital papillae = 23 (22 + 1) in number and, for the first generation female, excretory pore = 75.7 (60-108) μm, pharynx = 174 (158-200) μm and tail length = 43.2 (38-60) μm. Steinernema bifurcatum n. sp. is distinguished from all other members of the bicornutum group by the presence of a gubernaculum which is bifurcated at both proximal and distal ends in first generation males. On the basis of genital papillae number (22 + 1) it is close to S. abbasi, S. ceratophorum and S. pakistanense, but can be distinguished by morphometrics of IJ and adults. IJ of S. bifurcatum n. sp. can be differentiated from those of S. ceratophorum and S. pakistanense by the smaller body length of 460-590 μm. Steinernema bifurcatum n. sp. differs from S. abbasi by morphological characters of IJ, male and female stages. The IJ can be distinguished by D% (33-47), body diam. (20-24) μm, b value (3.8-5.6) and pharynx length (102-134) μm. The second generation male differs by GS ratio (0.29-0.45) and the mucronate tail. The first generation female is distinguished by a protruding vulva and no postanal swelling. Analysis of ITS rDNA (824 bp), D2-D3 (880 bp) and mt DNA region (507 bp) sequences confirm that the studied nematode isolate represents a valid new species, the combination of molecular and morphological features indicating that it belongs to Clade IV, the bicornutum group.


Nematology ◽  
2016 ◽  
Vol 18 (2) ◽  
pp. 235-255 ◽  
Author(s):  
Birhan A. Abate ◽  
Antoinette P. Malan ◽  
Louwrens R. Tiedt ◽  
Michael J. Wingfield ◽  
Bernard Slippers ◽  
...  

A new species of entomopathogenic nematode, Steinernema fabii n. sp., was isolated by trapping with wax moth (Galleria mellonella) larvae from soil in an Acacia mearnsii plantation in the Mpumalanga province of South Africa. The new species is morphologically characterised by the length of the infective juvenile (IJ) of 641 (590-697) μm, by a tail length of 58 (52-64) μm, ratio a = 24 (21-41), H% = 53 (37-61) and E% = 93 (83-105). The pattern of the lateral field of the IJ of the new species is 2, 5, 2 ridges (3, 6, 3 incisures). The male of the first generation can be recognised by the long spicule of 90 (79-106) μm and gubernaculum of 66 (56-77) μm; D% = 64 (52-75) and GS% = 73 (63-86). The first generation female can be recognised by a protruding vulva with a short, double-flapped epiptygmata, and the lack of a postanal swelling, while the second generation differs in having a postanal swelling and a conical, sharply pointed tail. Analysis of DNA sequences for the ITS and D2-D3 gene regions showed S. fabii 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, S. sacchari and S. fabii n. sp., all from the African continent. This group is closely related to species in the feltiae-kraussei-oregonense Clade III.


2012 ◽  
Vol 88 (2) ◽  
pp. 139-151 ◽  
Author(s):  
A.P. Malan ◽  
R. Knoetze ◽  
L. Tiedt

AbstractA new entomopathogenic nematode in the genus Heterorhabditis is described from South Africa, from two singular isolates found 1000 km from each other, from beneath a fig tree and in a citrus orchard, respectively. Morphological and molecular studies indicate both isolates to be the same and a new undescribed Heterorhabditis species. Comparison of sequences of the internal transcribed spacer (ITS) rDNA and the D2D3 region of the 28S rDNA gene with available sequences of other described species within the genus, indicate the two isolates as a new species. Phylogenetic analysis of the sequence data concerned placed the new species, H. noenieputensis n. sp., closest to H. indica and H. gerrardi in the indica-group. The new species, H. noenieputensis n. sp., is distinguished from other species in the genus by a combination of several morphological traits of the males and the infective juveniles (IJs). The new species differs from all other species previously described, as regards the body length of the IJs, except for H. indica and H. taysearae, in which the IJ is smaller. The IJ also differs from that of H. indica in the length of the oesophagus, the body diameter, the length of the tail and the E%. In addition, males of H. noenieputensis n. sp. differ from their closest relative, H. indica, in the position of the excretory pore, SW% and D%; and from H. gerrardi in the length of the oesophagus and SW%. The seventh pair of genital papillae of H. noenieputensis n. sp. are normally developed, while for H. indica they are often branched or swollen at the base, while 8 and 9 are usually absent in both species.


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.


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. 


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