Discovery and description of the "davtiani" morphotype for Teladorsagia boreoarcticus (Trichostrongyloidea: Ostertagiinae) abomasal parasites in muskoxen, Ovibos moschatus, and caribou, Rangifer tarandus, from the North American Arctic: implications for parasite faunal diversity

Collections to explore helminth diversity among free-ranging ungulates in the North American Arctic revealed the occurrence of a third male, or " davtiani ," morphotype for Teladorsagia boreoarcticus . Designated as T. boreoarcticus forma (f.) minor B, the males occurred with T. boreoarcticus f. major and T. borearcticus f. minor A in endemic populations of muskoxen (Ovibos moschatus wardi) and barrenground caribou (Rangifer tarandus groenlandicus) on Victoria Island, Nunavut, Canada, and in muskoxen and Peary caribou ( Rangifer tarandus pearyi ) on Banks Island, Northwest Territories, Canada. These specimens differ from conspecific morphotypes in the structure of the genital cone and Sj?berg's organ. Relative to T. boreoarcticus f. minor A, specimens of T. boreoarcticus f. minor B are consistently smaller, and mean dimensions for the bursa and spicules do not overlap. The robust spicules are similar in form, particularly in the relative length of the dorsal and ventral processes, but mean total length is substantially less in specimens of T. boreoarcticus f. minor B. Differences that distinguish the minor morphotypes of T. boreoarcticus parallel those demonstrated for the T. trifurcata and T. davtiani morphotypes in association with T. circumcincta sensu stricto. New host and geographic records include the 3 morphotypes of T. boreoarcticus in muskoxen and Peary caribou from Banks Island and in barrenground caribou from Victoria Island. Recognition of the ubiquitous nature of cryptic species emphasizes the need to effectively develop and use our collections-based resources and museum archives to build a robust understanding of the biosphere. Field inventory should include provisions for integrative approaches that preserve specimens suitable for comparative morphology, multi-faceted molecular investigations, and population genetics.     

Steinernema aciari sp. n. (Nematoda: Steinernematidae), a new entomopathogenic nematode from Guangdong, China

A new species of entomopathogenic nematode, Steinernema aciari sp. n. was described. It was recovered from a soil sample collected from Haimen town, Shantou district in the eastern coast of Guangdong province, the People's Republic of China during a survey for entomopathogenic nematodes. S. aciari sp. n. belongs to the Steinernema glaseri group. It can be separated from all described Steinernema species by the combined morphological and morphometrical characters of various stages of the nematodes. For male, the new species can be recognized by spicule length (86+/-6.3 microm); spicule tip blunt with a hook-like structure; gubernaculum with a short and Y-shaped cuneus and corpus well-separated posteriorly. For infective juvenile, the combination of the following characters: body length (1113+/-68 microm), distance from anterior end to excretory pore (95+/-3.7 microm), tail length (78+/-5.2 microm), and E % (123+/-7) can be used to differentiate the new species from other nematodes. For female, the tail (conoid with a long mamillate terminus and a distinct postanal swelling) and vulva (slightly protruding from body surface with conspicuous double flapped epiptygma) shapes can be used as diagnostic characters for the new species. 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 regions of rDNA, and from the close related species S. glaseri, Steinernema longicaudum CWL05, and Steinernema guangdongense by cross-breeding test.     

Steinernema ceratophorum n. sp. (Nematoda: Steinernematidae), a new entomopathogenic nematode from north-east China

Steinernema ceratophorum n. sp. was isolated from soil in Liaoning and Jining Provinces of China. Morphological, cross-breeding and DNA studies support the distinctiveness of S. ceratophorum n. sp. in comparison with four morphologically similar Steinernema species: S. affine, S. intermedium, S. riobrave and S. bicornutum. Diagnostic characters include: body length of infective juvenile, juvenile lip region with two horn-like structures and lateral field with six or eight longitudinal ridges; tail tip of first and second generation males lacking mucron; spicules of first generation male curved, dark yellow in colour and 71 µm long; tail tip of first generation female with small mucronate projection; and second generation female with fine mucronate process about 5.5 µm long. In addition, the restriction fragment length pattern (RFLP) of the ITS region of the ribosomal DNA repeat unit is different from other Steinernema spp., and S. ceratophorum n. sp. did not hybridise with S. riobrave, the species with the most similar RFLP.     

Meloidogyne polycephannulata n. sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitizing carrot in Brazil

Meloidogyne polycephannulata n. sp. is described from specimens collected from an area cultivated with carrot cv. Brasilia, in the city of Rio Paranaíba, in the region of Alto Paranaíba, Minas Gerais State, Brazil. The perineal pattern of the female is circular to ovoid with a high dorsal arch that has widely spaced, coarse annulations. The lateral field may have a deep furrow separating the dorsal and ventral arches. The medial lips are short and wide, whereas the lateral lips are large and triangular. The female stylet is 15-16 μm long with wide knobs, distinctly divided by an indentation in the center. Its tip is slightly curved dorsally. The excretory pore opens 34-65 μm from the anterior end. Females retain eggs and second-stage juveniles in their body cavity, similar to that of the cyst-forming nematodes. Males are 1.3-1.7 mm long and have a high head cap that is rounded and slopes posteriorly. The labial disc is fused to the medial lips. The head region has several irregular annulations that are similar in appearance to the first or second body annules that are likewise irregular, making the head region appear to be extremely large. The stylet of the male is 21-24 μm long; it is slender, and has small, rounded knobs, that are distinctly indented medially and appear heart-shaped. The shaft has several tiny projections throughout its length. Mean second-stage juvenile length is 411.7 μm. The juvenile head cap is elevated, the medial lips are small, and the lateral lips are elongate to triangular-shaped. The head region has several short, incomplete and irregular transverse annulations. The juvenile stylet is 14-23 μm long with small, rounded, and sloping knobs. The thin tail ends with a short hyaline portion that is variable in size (16-26 μm) and with a small, rounded tip. Isozyme profiles of esterases from Meloidogyne javanica show 3 strong bands (SB) at Rm 46, 59, and 66; profiles of M. polycephannulata n. sp. show a SB at Rm 47 and a weak band (WB) at Rm 52; M. petuniae has two SB at Rm 44 and 53; M. phaseoli has a SB at 53, 58, and 64 Rm; M. brasilensis has three SB at Rm 40, 58, and 66 and a WB at Rm 71; M. pisi has a SB at Rm 40, 60, and 64 and two WB at 46 and 50 Rm. Data from sequencing the 18S rDNA region of M. polycephannulata n. sp. confirms that it is different from M. arabicida, M. arenaria, M. ethiopica, M. incognita, M. javanica, M. paranaensis, and M. thailandica. Sequence identity among these eight species ranged between 85 to 93.4%. Meloidogyne polycephannulata n. sp. reproduces very well on carrot and tomato; poorly on pepper; and not at all on cotton, peanut, tobacco, watermelon, and sweet corn.     

Heterorhabditis atacamensis n. sp. (Nematoda: Heterorhabditidae), a new entomopathogenic nematode from the Atacama Desert, Chile

A new Heterorhabditis species of entomopathogenic nematode was isolated from soil of the Atacama Desert in Chile. The new species is characterized by morphometrics of the infective juvenile (IJ) with length (L)?=?611 (578-666)?μm, head to excretory pore length (EP)?=?115 (101-126)?μm, tail?=?69 (62-79)?μm long, (EP/tail)?×?100 (E%)?=?165 (149-182) and L/maximum body diameter (ratio a)?=?28 (25-31). The male has spicules 45 (40-49)?μm long, gubernaculum 20 (17-22)?μm long and (spicule length/anal body diameter)?×?100 (SW%)?=?205 (179-249). The hermaphroditic adult has shallow cuticular folds immediately anterior and posterior to the vulva, a slight post-anal swelling and a finely rounded tail terminus. Morphologically, H. atacamensis n. sp. resembles H. safricana, H. marelatus, H. downesi and H. amazonensis, but can be distinguished by characters of adult and IJ stages. In particular, for adult males, H. atacamensis n. sp. differs from H. amazonensis by the number and orientation of the genital papillae and from H. downesi by the position of the excretory pore; by the shape of the female tail terminus from H. downesi and by the position of the IJ hemizonid from H. marelatus. Heterorhabditis atacamensis n. sp. is further characterized by internal transcribed spacer (ITS) and D2D3 rDNA sequences, the closest species, H. safricana, being separated by 13?bp across 730?bp of the ITS (incorporating ITS1 (partial sequence), 5.8S (complete sequence), ITS2 (complete sequence)) and 5?bp across 592?bp of the partial 28S (incorporating D2D3) sequence. The morphological and molecular data confirm that H. atacamensis n. sp. is a valid species.     

A New Ataloderinae (Nematoda: Heteroderidae), Thecavermiculatus gracililancea n. gen., n. sp.

Thecavermiculatus gracililancea n. gen., n . sp. is described from the roots of Festuca myuros L. ("rattail fescue") a range grass in Monterey County, California. Thecavermiculatus females have a slight terminal prominence on which are located the vulva and anus, while its closest relatives, Atalodera and Sherodera, have a large terminal prominence. Furthermore, in T. gracililancea the hatched second-stage juveniles are retained in the female body while Atalodera and Sherodera females retain embryonated eggs.     

Meloidogyne hispanica n. sp. (Nematoda: Meloidogynidae), the 'Seville Root-Knot Nematode'

Meloidogyne hispanica n. sp. is described and illustrated from specimens obtained from peach rootstock, Prunus persica silvestris Batsch, from the Seville district of Spain. The perineal pattern of the female is oval shaped to rectangular with low dorsal arch and often widely spaced lateral lines with fringe-like striae. The stylet, 14.1 μm long, has broad, distinctly set off knobs. Males have a high, rounded head cap that slopes posteriorly. Labial disc and medial lips are fused to form elongate lip structures. The robust styler, 23.5 μm long, has large, rounded knobs that are slightly set off from the shaft. Mean second-stage juveniles length is 392.6 μm. The truncate head region is generally not annulated. The distinctly rounded and raised labial disc and the crescent-shaped medial lips form dumbbell-shaped lip structures. The stylet, 11.1 μm long, has rounded, posteriorly sloping knobs. The slender tail, 46.4 μm long, has large irregular-sized annules in the posterior region and ends in a bluntly rounded tip. Tomato was a good host; tobacco, pepper, and watermelon were poor hosts; cotton and peanut were nonhosts. Meloidogyne hispanica n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of 2n = 33-36. The esterase pattern is unique among Meloidogyne species.     

Oscheius basothovii n. sp. (Nematoda: Rhabditidae), a new entomopathogenic nematode isolated from an uncultivated grassland in South Africa

During a recent soil sample survey in Heidelberg at the Suikerbosrand Nature Reserve near Johannesburg in South Africa, a new entomopathogenic nematode species, collected from the grassland was discovered. Oscheius basothovii was isolated from soil samples using the Galleria mellonella bait method. Amplification and Sanger sequencing of the 18S ribosomal DNA placed the nematode in genus Oscheius. Morphological studies with light and scanning electron microscopy confirmed its anatomical affinities with the genus. The new species is characterised by various traits including its original 18S rDNA sequence, six lips, and amphidelphic reproduction. Males were characterised by the presence of spicules towards their posterior end and short blunt tails. Females had a body with irregular ridges, a vulva opening, and long pointed tails. The infective juveniles of this new species are able to invade Galleria mellonela and Tenebrio molitor larvae and cause mortality within 24–72?h after inoculation under laboratory conditions.     

Longidorus paravineacola n. sp. (Nematoda: Longidoridae), a New Species from Arkansas

Longidorus paravineacola n. sp., described herein, was found in a survey of longidorids of Arkansas. It is a parthenogeneticspecies characterized by its long body (6.68-9.85 mm); slightly expanded and rounded head, head width 21-27 µm; odontostyle length 95-114 µm; guide ring 28-37 µm posterior to the head end; short rounded tail, and c'' = 0.6-1.0. Longidorus paravineacola n. sp. is similar to the amphimictic species L. vineacola Sturhan &Weischer, 1964; L. balticus Brzeski, Peneva &Brown, 2000; L. kuiperi Brinkman, Loof &Barbez, 1987; and parthenogenetic species L. crassus Thorne, 1974, which also occurred in the type locality.     

Longidorus grandis n. sp. and L. paralongicaudatus n. sp. (Nematoda: Longidoridae), Two Parthenogenetic Species from Arkansas

Two new parthenogenetic species of Longidorus were found in Arkansas. Longidorus grandis n. sp. is characterized by its body (5.80-8.24 mm), slightly offset head, head width 20-27 µm, odontostyle 86-100 µm, guide ring 26-35 µm posterior to the anterior end, short conoid to mammiliform tail. Longidorus grandis n. sp. is similar to L. vineacola Sturhan &Weischer, 1964; L. lusitanicus Macara, 1985; L. edmundsi Hunt &Siddiqi, 1977; L. kuiperi Brinkman, Loof &Barbez, 1987; L. balticus Brzeski, Peneva &Brown, 2000; L. closelongatus Stoyanov, 1964; and L. seinhorsti Peneva, Loof &Brown, 1998. Longidorus paralongicaudatus n. sp. is characterized by its body length (2.60-5.00 µm), anteriorly flattened and offset head region 13-18 µm wide, odontostyle length 92-127 µm, guide ring 21-30 µm posterior to the anterior end, tail elongate-conical, and c'' = 1.2-2.6. Longidorus paralongicaudatus n. sp. most closely resembles L. longicaudatus Siddiqi, 1962; L. socialis Singh &Khan, 1996; L. juvenilis Dalmasso, 1969; and L. curvatus Khan, 1986.     

Steinernema siamkayai n. sp. (Rhabditida: Steinernematidae), an entomopathogenic nematode from Thailand

Steinernema siamkayai n. sp. (Rhabditida: Steinernematidae) is a new entomopathogenic nematode isolated in Lohmsak, Thailand. Morphology, hybridisation and molecular studies indicated the distinctness of S. siamkayai n. sp. from other Steinernema spp. Diagnostic characters include: the total body length (398–495 m) and tail length (31-41m) of the third-stage infective juvenile and lateral field pattern with 6-8 longitudinal ridges; the presence of a tail mucro in both first and second generation females and males; the size and shape of the spicules and gubernaculum, and the arrangement of the genital papillae of the first and second generation males; and the shape of the vulva and tail of the first generation female and second generation female     

Steinernema weiseri n. sp. (Rhabditida,Steinernematidae), a new entomopathogenic nematode from Europe

Steinernema weiseri n. sp. is described from a roadside with apple trees near Ceské Budejovice, Czech Republic. The species is also widely distributed in Germany and Slovakia, from where it had previously been reported as Steinernema spec. F. The British Steinernema sp. D1 is considered conspecific with S. weiseri n. sp. Males of the new species are mainly characterised by light brown, slightly curved spicules with a long manubrium and the presence of a short tail mucron in the second generation. Third-stage infective juveniles are characterised by a `medium size' body and tail length, short hyaline tail portion (mostly around 1/3 of tail length), the excretory pore situated in the mid-pharynx region, lip region slightly offset, angular and flattened, and the lateral field having nine equally developed lines separated by eight distinct ridges. S. weiseri n. sp. is most similar to S. feltiae, with which it did not hybridise. RFLP analysis of the ITS region of the rDNA repeat shows S. weiseri n. sp. to be distinct from 50 other Steinernema species and isolates. The new species was found in a wide range of habitats and is readily maintained on Galleria mellonella larvae.     

Two new nematode species, Orientatractis campechensis n. sp. and Orientatractis chiapasensis n. sp. (Nematoda: Atractidae) from cichlid fishes in southern Mexico and Nicaragua

Two new nematode species, Orientatractis campechensis n. sp. and Orientatractis chiapasensis n. sp. (Atractidae, Cosmocercoidea), are described from the intestine of cichlid fishes collected in localities of southeastern Mexico and Nicaragua. These atractid nematodes are characterized by the presence of a cephalic end armed with 4 marked, Y-shaped, well-sclerotized pieces, consisting of 2 "horns" extending outward and downward and immediately below a single-horned structure. Both new species differ from the other 2 species of Orientatractis (Orientatractis leiperi and Orientatractis levanhoai) mainly in the body measurements, presence of a vulvar appendix, lengths of spicules and of the gubernaculum, distribution of caudal papillae, and the number of anterior sclerotized structures. Morphological and biometrical variations were evident among specimens from different hosts and localities, with the larger organisms being collected from Vieja bifasciata and Cichlasoma pearsei. Orientatractis campechensis and O. chiapasensis represent the first 2 species of this genus parasitizing freshwater fishes; the other species have been found in amphibians and reptiles.     

Steinernema ichnusae sp. n. (Nematoda: Steinernematidae) a new entomopathogenic nematode from Sardinia Island (Italy)

A new Steinernema species was isolated from three different sandy soil samples along the Platamona Beach, in the north-west coast of Sardinia Island (Italy). This new species is characterized by the following morphological characters: infective third-stage juvenile with a body length of 866 ± 61 (767-969) μm, distance from head to excretory pore of 63 ± 2.7 (59-68) μm, tail length of 81 ± 3.2 (76-89) μm, ratio E (%) 77 ± 3.4 (68-83); male tail with a mucron only in the second generation, spicule length of 66 ± 1.4 (64-67) μm and gubernaculum length of 44 ± 1.4 (43-46) μm in the first generation male; female of first generation with a slight vulval protrusion and ratio D (%) of 53 ± 4.0 (47-63). The new species differs distinctly from the related species (S. feltiae, S. kraussei, S. litorale, S. oregonense and S. cholashanense) in some morphometric values such as percentage of hyaline portion, ratios of gubernaculum/spicule length, spicule head length/width. The DNA analyses of the internal transcribed spacers and D2D3 regions show that the studied nematode isolates are a new species. Cross hybridisation tests with S. feltiae, S. kraussei, S. litorale, S. weiseri and S. oregonense showed that these species were reproductively isolated.