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Summary The study aims to provide the morphological and molecular characterisation of two newly discovered Cryptaphelenchus species, namely: C. curvatum n. sp. and C. tumidus n. sp. Morphologically both species are minute nematodes, possess medium-sized stylets with basal knobs laterally directed, and short post-uterine sacs (PUS). Cryptaphelenchus curvatum n. sp. was detected from the local Pinus branch samples and is characterised by having an equal proportion of adult males and females, medium-sized body lengths of females 353 (320-388) μm and males 277 (256-293) μm, lateral fields with four lateral lines, 8-10 μm long stylet, PUS about one vulva body width long and conical posterior body end with a blunt pointed tip. Cryptaphelenchus tumidus n. sp. was detected in a packaging wood sample from Japan and is characterised by having rare male, short body lengths of females 236 (217-270) μm and males 180 μm, obscure lateral fields, stylet 6.8 (6.0-7.5) μm, PUS about half vulva body width long and a slim conical posterior body end with a finely rounded tip. The phylogenetic trees were also constructed based on rRNA gene sequences (D2-D3 segments of the 28S, ITS and 18S) and discussed in detail. Since Cryptaphelenchus species offer multitrophic relationships among their insect vectors and associated microbiota, species recognition and molecular studies of recovered populations will facilitate researchers to determine whether these species might play any ecological roles in insect bionomics or the residing host tree.

Criconemoides neoinformis n. sp., a cryptic species of C. informis group, and C. persicus n. sp. were recovered from the rhizosphere of pear and grass, in Zanjan and West Azerbaijan provinces, northwestern Iran, respectively. Criconemoides neoinformis n. sp. is characterised by 522-585 μm long females, having four separated pseudolips, anteriorly flattened lip region comprised of two annuli, 57-63 retrorse body annuli with smooth to slightly crenate margins, without anastomoses, 86.9-90.4 μm long stylet, having 6-10 annuli from vulva to posterior end and tail conical rounded with two, three or multilobed terminus and presence of males. Criconemoides persicus n. sp. could be characterised by flatly rounded lip region, having fused rectangular pseudolips, 515-615 μm body length, stylet 60-65 μm, body annuli 120-132 with smooth to slightly crenate margins, without anastomoses, 9-12 annuli from vulva to posterior end and tail conical rounded with two trilobed terminus. In inferred phylogenies, these two new species clustered with known Criconemoides species in 18S, 28S, ITS and COI trees. These species are clearly separated molecularly by all the studied markers. The use of molecular markers, mainly D2-D3 expansion segments of 28S rRNA, ITS region and COI, are very promising in the case of cryptic species found in this group of nematodes. We provided molecular markers (two sequences per marker) for these new species with morphological/morphometrical data using an integrative taxonomy approach for the unequivocal identification of these species., The authors thank the University of Jaén, Spain, for financial support received for the Research Support Plan PAIUJA 2019/2020: EI_RNM02_2019. SEM pictures were obtained with the assistance of technical staff (Amparo Martínez-Morales) and equipment of the ‘Centro de Instrumentación Científico-Técnica (CICT)’ at the University of Jaén.

Ring nematodes are obligate ectoparasites on crops and natural herbaceous and woody plants, and some species are of economic importance and cause damage to roots of several crops. Recent integrative taxonomical analyses recognized the existence of two cryptic species within the Criconema annuliferum morphotype in Spain. In this study, we corroborated that morphometric, morphological and a multi-locus analysis (including the ribosomal markers D2-D3 expansion segments of 28S rRNA, ITS rRNA, 18S RNA, and the mitochondrial DNA cytochrome oxidase I gene) identified a new lineage clearly separated from C. annuliferum, C. paraannuliferum and C. plesioannuliferum. The new lineage was described herein as Criconema pseudoannuliferum sp. nov., confirming that C. annuliferum species complex species complex comprises a hyper-cryptic species complex. This research analysed soil samples from the rhizosphere of maritime pine (Pinus pinaster Ait.) forests in Bermeja-Crestellina Mountain, located at the western part of Málaga province, southern Spain. The integrative taxonomical analyses revealed the occurrence of a new cryptic species identified using females, males and juveniles with detailed morphology, morphometry and molecular markers, described herein as Criconema pseudoannuliferum sp. nov. All molecular markers (D2-D3, ITS, 18S and COI) were obtained from the same individual that was also used for morphological and morphometric analyses. This research demonstrated the hidden diversity within the C. annuliferum species complex species complex can reach to four lineages under ribosomal and mitochondrial gene markers for one morphospecies group, which includes four species, viz. C. annuliferum, C. paraannuliferum, C. plesioannuliferum, and C. pseudoannuliferum sp. nov. Criconema pseudoannuliferum sp. nov. was detected in moderate soil density in two maritime pine forests (5 and 25 nematodes/500 cm3 of soil) suggesting that does not cause damage to maritime pine., This research was supported by the Spanish Ministry of Science, Innovation and Universities, grant number RTI2018-095345-B-C21, LITHOFOR (“Modulating role of LITHOlogy in the response of Mediterranean FORest ecosystems to climate change: growth, edaphological processes and future predictions”); and grant RYC2021-031108-I, funded by MCIN/AEI/10.13039/501100011033 and UE “Next Generation EU/PRTR”.

The presence of plant-parasitic nematodes (PPNs) in cultivated areas is a limiting factor in achieving marketable crop yield. To control and alleviate the effects of these nematodes and determine appropriate management strategies, species-level identification is crucial. Therefore, we conducted a nematode diversity survey, which resulted in the detection of four Ditylenchus species in cultivated areas of southern Alberta, Canada. The recovered species had six lines in the lateral field, delicate stylets (>10 µm long), distinct postvulval uterine sacs, and pointed to rounded tail tips. The morphological and molecular characterization of these nematodes revealed their identity as D. anchilisposomus, D. clarus, D. tenuidens and D. valveus, all of which are members of the D. triformis group. All of the identified species were found to be new records in Canada except for D. valveus. Accurate Ditylenchus species identification is crucial because false-positive identification can result in the implementation of quarantine measures over the detected area. Our current study not only documented the presence of Ditylenchus species from southern Alberta, but also described their morpho-molecular characteristics and subsequent phylogenetic relationships with related species. The results of our study will aid in the decision on whether these species should become a part of nematode management programs since nontarget species can become pests due to changes in cropping patterns or climate., This work was supported by the Potato Early Dying Complex project funded by the University of Lethbridge Research Operating Fund, and the Canadian Potato Early Dying Network project funded by the Canadian Agri-Science Cluster for Horticulture 3 grant to D.P.Y., in collaboration with the Potato Growers of Alberta (Taber, AB, Canada), McCain Foods Canada Ltd. (Chin, AB, Canada), Cavendish Farms Corp. (Lethbridge, AB, Canada), and Lamb Weston Inc. (Purple Springs, AB, Canada).

Summary Hemicycliophora species are migratory root ectoparasites of higher plants, commonly known as sheath nematodes. The present study describes a new species, Hemicycliophora geraerti n. sp., recovered from the rhizosphere of peach tree (Prunus persica) in Zhejiang Province, China. This species is characterised by a cuticular sheath loosely fitting to the body, a lip region slightly set-off with body contour bearing 3-4 annuli, oral plate narrow, ovate, and non-protruding, amphidial apertures plugged, dorsoventrally flanked in the first lip annulus, stylet 110 (103-116) μm long and flexible, excretory pore located 4-7 annuli posterior to the base of the pharyngeal bulb; vulval lips modified with a small vulval sleeve, anus located 16 (13-21) annuli posterior to vulva, tail elongated, having a narrowly rounded slightly offset spike. The molecular characterisation and phylogenetic analyses based on D2-D3 expansion segments of the 28S rRNA, ITS rRNA, and COI mtDNA gene indicated the unique status and support the novelty of this population of Hemicycliophora, therefore herein described as H. geraerti n. sp., This research was supported by the National Natural Science Foundation of China (No.31772137).

Ring nematodes are obligate ectoparasites on cultivated and wild herbaceous and woody plants, inhabiting many types of soil, but particularly sandy soils. This study explored the morphometrical and molecular diversity of ring nematodes resembling Criconema annuliferum in 222 soil samples from fruit crops in Spain, including almond, apricot, peach and plum, as well as populations from cultivated and wild olives, and common yew. Ring nematodes of the genus Criconema were detected in 12 samples from under Prunus spp. (5.5%), showing a low to moderate nematode soil densities in several localities from southeastern and northeastern Spain. The soil population densities of Criconema associated with Prunus spp. ranged from 1 nematode/500 cm3 of soil in apricot at Sástago (Zaragoza province) to 7950 and 42,491 nematodes/500 cm3 of soil in peach at Ricla and Calasparra (Murcia province), respectively. The integrative taxonomical analyses reveal the presence of two cryptic species identified using females, males (when available), and juveniles with detailed morphology, morphometry, and molecular markers (D2-D3, ITS, 18S, and COI), described herein as Criconema paraannuliferum sp. nov. and Criconema plesioannuliferum sp. nov. All molecular markers from each species were obtained from the same individuals, and these individuals were also used for morphological and morphometric analyses. Criconema paraannuliferum sp. nov. was found in a high soil density in two peach fields (7950 and 42,491 nematodes/500 cm3 of soil) showing the possibility of being pathogenic in some circumstances., This research was supported by grant RTI2018-095925-A-100 from Ministerio de Ciencia, Innovación y Universidades, Spain and European Union inside the European Regional Development Fund (ERDF).

Paratylenchus species are obligate ectoparasitic nematodes on cultivated and wild herbaceous and woody plants occupying numerous soil categories. Several species may cause damage to several crops (viz. P. dianthus, P. enigmaticus, P. microdorus, P. hamatus and P. epacris on carnation, lettuce, rose and walnut, respectively). This investigation proves and emphasizes the relevance of applying integrative taxonomy for the accurate detection of Paratylenchus species in mountainous wild environments in the Malaga province, Southern Spain. This research analyzed 45 soil samples of maritimus pine and one of green heather in southern Spain and identified fourteen Paratylenchus species, two of them are described herein as new species (P. paraaonli sp. nov., P. plesiostraeleni sp. nov.), six of them were first reports for Spain (P. canchicus, P. nainianus, P. neonanus, P. salubris, Paratylenchus sp. 2 SAS, and P. wuae), and six species (P. caravaquenus, P. microdorus, P. nanus, P. neoamblycephalus, P. sheri, and P. variabilis) have been already reported in Spain. Accordingly, these data increase the biodiversity of pin nematodes in Spain comprising a total of 47 species (33.1% out of 142 total species of this genus). Phylogenetic analyses based on ribosomal and mitochondrial markers (D2-D3, ITS, and partial COI) resulted in a consistent position for the newly described Paratylenchus species in this study (P. plesiostraeleni sp. nov., P. paraaonli sp. nov.). Paratylenchus plesiostraeleni sp. nov. grouped in a separated subclade as unequivocal species from the P. straeleni-complex species (including P. straeleni and P. parastraeleni), and P. paraaonli sp. nov. clustered with P. vitecus, but clearly separate from this species. This study indicates that Paratylenchus species diversity in natural environments may be higher than expected, and this study may help in accurate identifications., This research was supported by Spanish Ministry of Science, Innovation and Universities, grant number RTI2018-095345-B-C21, LITHOFOR (“Modulating role of LITHOlogy in the response of Mediterranean FORest ecosystems to climate change: growth, edaphological processes and future predictions”).

This article belongs to the Special Issue Plant Parasitic Nematodes., Root-lesion nematode species rank third only to root-knot and cyst nematodes as having the greatest economic impact on crops worldwide. A survey of plant-parasitic nematodes associated with decaying raspberries (Rubus sp.) in northern Italy revealed that root-lesion nematodes were the most frequently occurring species among other phytonematodes. Several Pratylenchus species have been associated with Rubus sp. in Canada (Quebec, British Columbia) and USA (North Carolina, Maryland, New Jersey) including P. penetrans and P. crenatus. In the roots and rhizosphere of symptomatic raspberries, nematodes of two Pratylenchus spp. were detected. Detailed morphometrics of the two root-lesion nematode isolates were consistent with Pratylenchus crenatus and with an undescribed Pratylenchus species. The extracted nematodes were observed and measured as live and fixed materials and subsequently identified by integrative taxonomy (morphometrically and molecularly). The latter species is described herein as Pratylenchus vovlasi sp. nov., resulting morphometrically closest to P. mediterraneus and phylogenetically to P. pratensis. The molecular identification of Pratylenchus vovlasi sp. nov. was carried out by sequencing the ITS region, D2-D3 expansion domains of the 28S rRNA gene and a partial region of the nuclear hsp90 gene. ITS-RFLP and sequence analyses revealed that Pratylenchus vovlasi sp. nov. had species-specific restriction profiles with no corresponding sequences present in the database. The phylogenetic relationships with ITS and D2-D3 sequences placed the Pratylenchus vovlasi sp. nov. in a clade with P. pratensis and P. pseudopratensis. This research confirms the occurrence of cryptic biodiversity within the genus Pratylenchus as well as the need for an integrative approach to the identification of Pratylenchus species., F.D.L. acknowledges the Piedmont region through project NEMVIR/302/2010.

Specimens of a thin longidorid species collected in Peñalba (Huesca), north-west Spain, were previously described as Paralongidorus iberis. However, we conclude, through scanning electron microscopy and molecular studies on a population from about 15 km from the type locality and on paratype specimens, that this species was originally placed in the wrong genus. Both populations have pore-like amphidial apertures, not slit-like as in Paralongidorus, and the species is therefore transferred to Longidorus. Longidorus iberis n. comb. is regarded as a valid species and is clearly different from closely related species such as L. tabernensis, L. iliturgiensis, L. alvegus and L. indalus in morphometrics and molecular markers. Molecular data are reported for the first time, including the D2-D3 expansion segments of 28S rRNA, ITS1 rRNA, partial 18S rRNA and partial mitochondrial coxI regions. These molecular markers were used for inferring the phylogenetic relationships with other species within Longidorus and Paralongidorus, all clearly separating L. iberis n. comb. from other related taxa and placing the species in the Longidorus clade, rather than with Paralongidorus., The first author is a recipient of a contract from the Ministry of Science and Innovation for Predoctoral Researchers in Spain, PRE2019-090206.

An intracellular bacterium, strain IAST, was observed to infect several species of the plant-parasitic nematode genus Xiphinema (Xiphinema astaregiense, Xiphinema incertum, Xiphinema madeirense, Xiphinema pachtaicum, Xiphinema parapachydermum and Xiphinema vallense). The bacterium could not be recovered on axenic medium. The 16S rRNA gene sequence of IAST was found to be new, being related to the family Burkholderiaceae, class Betaproteobacteria. Fungal endosymbionts Mycoavidus cysteinexigens B1-EBT (92.9 % sequence identity) and ‘Candidatus Glomeribacter gigasporarum’ BEG34 (89.8 % identity) are the closest taxa and form a separate phylogenetic clade inside Burkholderiaceae. Other genes (atpD, lepA and recA) also separated this species from its closest relatives using a multilocus sequence analysis approach. These genes were obtained using a partial genome of this bacterium. The localization of the bacterium (via light and fluorescence in situ hybridization microscopy) is in the X. pachtaicum females clustered around the developing oocytes, primarily found embedded inside the epithelial wall cells of the ovaries, from where they are dispersed in the intestine. Transmission electron microscopy (TEM) observations supported the presence of bacteria inside the nematode body, where they occupy ovaries and occur inside the intestinal epithelium. Ultrastructural analysis of the bacterium showed cells that appear as mostly irregular, slightly curved rods with rounded ends, 0.8–1.2 µm wide and 2.5–6.0 µm long, possessing a typical Gram-negative cell wall. The peptidoglycan layer is, however, evident only occasionally and not detectable by TEM in most cells. Another irregularly occurring shell surrounding the endosymbiont cells or the cell clusters was also revealed, probably originating from the host cell membrane. Flagella or spore-like cells do not occur and the nucleoid is diffusely distributed throughout the cell. This endosymbiont is transmitted vertically through nematode generations. These results support the proposal of IAST as a new species, although its obligate intracellular and obligate endosymbiont nature prevented isolation of a definitive type strain. Strain IAST is therefore proposed as representing ‘Candidatus Xiphinematincola pachtaicus’ gen. nov., sp. nov., This research was financially supported by grant 201740E042, ‘Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos’ from the Spanish National Research Council (CSIC) and grant RTI2018-095925-A-100 from the Ministerio de Ciencia, Innovación y Universidades, Spain. The first author acknowledges the Spanish Ministry of Economy and Competitiveness for the ‘Ramon y Cajal’ Fellowship RYC-2017-22228.

This article belongs to the Special Issue Plant Parasitic Nematodes., This study delves into the diagnosis of pin nematodes (Paratylenchus spp.) in Spain based on integrative taxonomical approaches using 24 isolates from diverse natural and cultivated environments. Eighteen species were identified using females, males (when available) and juveniles with detailed morphology-morphometry and molecular markers (D2-D3, ITS and COI). Molecular markers were obtained from the same individuals used for morphological and morphometric analyses. The cryptic diversity using an integrative taxonomical approach of the Paratylenchus straeleni-species complex was studied, consisting of an outstanding example of the cryptic diversity within Paratylenchus and including the description of a new species, Paratylenchus parastraeleni sp. nov. Additionally, 17 already known species were identified comprising P. amundseni, P. aciculus, P. baldaccii, P. enigmaticus, P. goodeyi, P. holdemani, P. macrodorus, P. neoamblycephalus, P. pandatus, P. pedrami, P. recisus, P. sheri, P. tateae, P. variabilis, P. veruculatus, P. verus, and P. vitecus. Eight of these species need to be considered as first reports for Spain in this work (viz. P. amundseni, P. aciculus, P. neoamblycephalus, P. pandatus, P. recisus, P. variabilis, P. verus and P. vitecus). Thirty-nine species of Paratylenchus have been reported in Spain from cultivated and natural ecosystems. Although we are aware that nematological efforts on Paratylenchus species in Southern Spain have been higher than that carried out in central and northern part of the country, the present distribution of the genus in Spain, with about 90% of species (35 out of 39 species, and 24 of them confirmed by integrative taxonomy) only reported in Southern Spain, suggest that this part of the country can be considered as a potential hotspot of biodiversity., This research was supported by grant RTI2018-095925-A-100 from Ministerio de Ciencia, Innovación y Universidades, Spain.

Reniform nematodes of the genus Rotylenchulus are semi-endoparasites of numerous herbaceous and woody plant roots that occur largely in regions with temperate, subtropical, and tropical climates. In this study, we compared 12 populations of Rotylenchulusborealis and 16 populations of Rotylenchulusmacrosoma, including paratypes deposited in nematode collections, confirming that morphological characters between both nematode species do not support their separation. In addition, analysis of molecular markers using nuclear ribosomal DNA (28S, ITS1) and mitochondrial DNA (coxI) genes, as well as phylogenetic approaches, confirmed the synonymy of R. macrosoma with R. borealis. This study also demonstrated that R. borealis (= macrosoma) from Israel has two distinct rRNA gene types in the genome, specifically the two types of D2-D3 (A and B). We provide a global geographical distribution of the genus Rotylenchulus. The two major pathogenic species (Rotylenchulusreniformis and Rotylenchulusparvus) showed their close relationship with warmer areas with high annual mean temperature, maximum temperature of the warmest month, and minimum temperature of the coldest month. The present study confirms the extraordinary morphological and molecular diversity of R. borealis in Europe, Africa, and the Middle East and comprises a paradigmatic example of remarkable flexibility of ecological requirements within reniform nematodes., This research was supported by grant RTI2018-095925-A-100 from Ministerio de Ciencia, Innovación y Universidades, Spain, grant 201740E042 “Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos” from the Spanish National Research Council (C.S.I.C.), and by the Humboldt Research Fellowship for Postdoctoral Researchers awarded to the third author (A.A.-Y.).

This article belongs to the Special Issue The Systematics, Morphological, and Molecular Characterization of Economically Important Plant–Parasitic Nematodes., Dagger nematodes of the genus Xiphinema include a remarkable group of invertebrates of the phylum Nematoda comprising ectoparasitic animals of many wild and cultivated plants. Damage is caused by direct feeding on root cells and by vectoring nepoviruses that cause diseases on several crops. Precise identification of Xiphinema species is critical for launching appropriate control measures. We deciphered the cryptic diversity of the Xiphinema hispanum-species complex applying integrative taxonomical approaches that allowed us to verify a paradigmatic example of the morphostatic speciation and the description of a new species, Xiphinema malaka sp. nov. Detailed morphological, morphometrical, multivariate and genetic studies were carried out, and mitochondrial and nuclear haploweb analyses were used for species delimitation of this group. The new species belongs to morphospecies Group 5 from the Xiphinema nonamericanum-group species. D2-D3, ITS1, partial 18S, and partial coxI regions were used for inferring the phylogenetic relationships of X. malaka sp. nov. with other species within the genus Xiphinema. Molecular analyses showed a clear species differentiation not paralleled in morphology and morphometry, reflecting a clear morphostatic speciation. These results support the hypothesis that the biodiversity of dagger nematodes in southern Europe is greater than previously assumed., This research was supported by Spanish Ministry of Science, Innovation and Universities, grant number RTI2018-095345-B-C21, LITHOFOR (“Modulating role of LITHOlogy in the response of Mediterranean FORest ecosystems to climate change: growth, edaphological processes and future predictions”) and the Humboldt Research Fellowship for Postdoctoral Researchers awarded for the first author.

Longidorid nematodes comprise more than 500 species, and Longidorus and Xiphinema are the most diversified, prevalent, and cosmopolitan genera within plant‐parasitic nematodes. This increases the risk of species misidentification. We conducted an integrative morphometric and genetic study on two longidorid species to elucidate the existence of new cases of cryptic speciation within the genera Longidorus and Xiphinema. Detailed morphological, morphometrical, multivariate, and genetic studies were carried out, and mitochondrial and nuclear haploweb analyses were used to differentiate species within the L. iliturgiensis and X. hispanum complexes. Species delimitation using multivariate and haplonet tools of L. iliturgiensis species complex clearly separated L. tabernensis sp. nov. from L. iliturgiensis and L. indalus, and X. subbaetense sp. nov. from X. hispanum and X. adenohystherum. D2‐D3, partial 18S, and partial coxI regions were used for inferring their phylogenetic relationships with other species in each genus. The present study provides new insights into the diversity of Longidorus and Xiphinema species detected in southern Spain, and new evidence of cryptic speciation in both genera. These results support our hypothesis that the biodiversity of Longidoridae in southern Europe is higher than previously supposed and is still not fully clarified., This research was supported by grant 201740E042 “Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos” from the Spanish National Research Council (C.S.I.C.) and by the Humboldt Research Fellowship for Postdoctoral Researchers awarded for the second author. The first author acknowledges the China Scholarship Council (CSC) for financial support. The second author is a recipient of Humboldt Research Fellowship for Postdoctoral Researchers at Helmholtz Centre for Environmental Research‐UFZ, Leipzig, Germany. The fourth author acknowledges Spanish Ministry of Economy and Competitiveness for the “Ramon y Cajal” Fellowship RYC‐2017‐22228.

Summary Sigmolenchus n. gen., is proposed as a new member of the Tylenchidae. The new genus is proposed based upon light and scanning electron microscopic (LM and SEM) observations and phylogenetic analyses based upon small, large and internal transcribed spacer sequences of ribosomal DNA (SSU, LSU D2-D3, ITS rDNA) and mitochondrial cytochrome c oxidase I gene (COI mtDNA) sequences. It is characterised partly by its slender body, but mainly by having a dorso-ventrally flattened, smooth and elevated cephalic region, unique elongate sinuous amphidial openings, each appearing as a wavy slit with three peaks, originating from the vicinity of the labial plate, extending posteriorly and reaching and passing the first body annulus, and a spacious amphidial fovea. It has an anteriorly rounded outline under LM, knobbed stylet, its conus comprising about one-third of the total length, lateral field with a single band, metacorpus with a distinct valve, vulva with small lateral flaps, and males common with tylenchoidiform spicules. The new genus is morphologically compared with seven tylenchid genera, viz., Chilenchus, Ecphyadophoroides, Filenchus, Labrys, Lelenchus, Sakia, and Tenunemellus, mainly by having small slender body and dorso-ventrally flat cephalic region, and is placed under the subfamily Ecphyadophorinae because of its slender body, elevated smooth cephalic region, long amphidial openings and spacious amphidial fovea. It was recovered from marine muddy sediments taken 2 m deep in mangrove forests off southern Iran. Currently S. sinuosus n. gen., n. sp. is monotypic. In SSU phylogeny, the new genus formed an unsupported sister relationship with Filenchus discrepans, and in LSU phylogeny it occupied a placement inside a major clade including several Tylenchinae genera.

Females and juveniles from a population of Xiphinema ifacolum from Sri Lanka are described based on morphology, morphometrics and molecular analyses. Morphologically, females and juveniles from Sri Lanka are similar to original descriptions and other reports from Brazil, Cameroon, Liberia, and São Tomé and Príncipe. The identity of the species was also confirmed by 18S rRNA gene sequences deposited in NCBI from Brazil (AY297826). Integrative diagnosis was completed with molecular data using D2-D3 expansion segments of 28S rRNA, ITS1 region, partial 18S-rRNA and the partial mitochondrial gene cytochrome c oxidase subunit 1 (coxI). This is the third molecular characterisation for a species of the X. non-americanum Group 4, after X. oleae and X. tica. The use of different ribosomal and mitochondrial markers in this study, particularly, D2-D3, ITS1 and partial coxI, provided a precise and unequivocal tool for the identification of X. ifacolum and contributes to a better knowledge of the diversity within Xiphinema. Morphospecies Group 4 appears to be a paraphyletic group within the X. non-americanum assemblage.

A new dagger nematode, Xiphinema poasense n. sp., is described and illustrated from three populations extracted from soil associated with a combined plantation of Eucalyptus sp., Cupressus sp. and Pennisetum sp. and wild plants from a tropical pre-montane forest in Costa Rica. The new dagger nematode is characterised by a moderate body size 2612 (2416-3042) μm long, a rounded lip region 15.0 (13.5-16.5) μm broad, separated from the body contour by a shallow depression, amphidial fovea large, stirrup-shaped, a very long odontostyle (175 (164-188) μm), stylet guiding ring located 167 (136-181) μm from anterior end, vulva situated anterior to mid-body (36-40%), anterior genital branch complete but strongly reduced, without uterine differentiation, female tail short, hemispherical to convex-conoid with a c′ ratio = 0.7 (0.6-0.8) and bearing two pairs of caudal pores, and male absent. Integrative diagnosis was completed with molecular data using D2-D3 expansion segments of 28S rRNA, ITS1 region, partial 18S-rRNA and the partial mitochondrial gene cytochrome c oxidase subunit 1 (coxI). The phylogenetic relationships based on D2-D3 segments of this species with other Xiphinema spp. of the X. non-americanum group indicated that X. poasense n. sp. clustered with other species with a reduced anterior genital branch from the morphospecies Group 2, viz., X. costaricense and X. krugi. However, the phylogeny of coxI and partial 18S rRNA gene revealed that the new species did not cluster with Xiphinema species having the anterior genital branch absent or reduced (i.e., morphospecies Groups 1 and 2, respectively)., The first author (I. Varela) is a DOCINADE programme student and grateful for the grant from the Ministerio de Ciencia, Tecnología y Telecomunicaciones of Costa Rica and from Consejo Nacional para Investigaciones Científicas y Tecnológicas for her research stay at the IAS-CSIC. Research was supported by a grant from Vicerrectoría de Investigación, Instituto Tecnológico de Costa Rica.

Radopholoides japonicus n. sp. isolated from rhizospheric soil samples associated with Podocarpus macrophyllus imported from Japan into Ningbo Port of China is described and illustrated. It is characterised by four lateral lines, lip region low, convex with three annuli. Stylet 16.5-18.5 μm long with anteriorly sloping rounded knobs. Excretory pore at the level of pharyngo-intestinal junction. Vulva posteriorly located, vulval lips not protruding, spermatheca squarish. Post-vulval uterine sac 35-44 μm long. Tail conoid with broadly rounded terminus, phasmid 6-8 annuli posterior to anus. Among five species of genus Radopholoides, the new species is close to R. antoni but can be differentiated from it by lip and tail morphology. This is the first Radopholoides species that provided detailed morphological and molecular characterisation. Maximum Likelihood analysis using the Shimodaira-Hasegawa test for the validity of Radopholoides was performed and showed the validity of the genus using the partial 18S and D2-D3 expansion segments of 28S., The research was supported by the Ningbo Science and Technology Innovation Team grant 2015C110018, and the General Administration of Quality Supervision, Inspection and Quarantine Issue grant 2016IK168 in China. The first author thanks the Chinese Scholarship Council (CSC) for providing the research fellowship.

The genus Longidorus constitutes a large group of approximately 170 species of plant-ectoparasitic nematodes that are polyphagous and distributed almost worldwide. Some of the species of this genus are vectors of plant viruses. Species discrimination in Longidorus is difficult because the morphology is very conservative, and morphometric characters often overlap, leading to potential misidentification. Integrative taxonomy, based on the combination of molecular analyses with morphology, is a useful and necessary approach in Longidorus species identification. In Spain from 2014 to 2017, we conducted nematode surveys among cultivated and wild plants, from which we identified 13 populations of Longidorus, two of which appeared to represent new species and are described herein as L. iliturgiensis sp. nov. and L. pacensis sp. nov., and 11 populations belonging to eight known species: L. africanus, L. baeticus, L. carpetanensis, L. fasciatus, L. nevesi, L. cf. olegi, L. pini, and L. vallensis. Three species are new geographical records for Spain (L. nevesi, L. cf. olegi, and L. africanus). We report molecular data for L. nevesi, L. cf. olegi, L. carpetanensis and L. pini for the first time. Additionally, we describe the males of L. pini and the juveniles of L. cf. olegi., Our research was supported by grants P12-AGR-1486 from ‘Consejería de Economía, Innovación y Ciencia’ of Junta de Andalucía, 219262 ArimNET_ERANET FP7 2012–2015 Project PESTOLIVE ‘Contribution of olive history for the management of soilborne parasites in the Mediterranean basin’ from Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), and FEDER financial support from the European Union is gratefully acknowledged. Antonio J. Archidona-Yuste is a recipient of the research fellowship BES-2013-063495 from the Spanish ‘Ministerio de Economía y Competitividad’.

Populations of Hemicriconemoides chitwoodi, H. fujianensis, H. parasinensis, and Criconemoides myungsugae isolated in China from the rhizosphere soil of woody perennials were characterised molecularly, important morphological details being elucidated by SEM observations. The morphometric data of the Chinese populations were compared with all previously reported populations. The SEM observations of en face views indicated that H. chitwoodi and H. parasinensis have lip patterns belonging to type 1 and phylogenetically both species clustered with other Hemicriconemoides species that showed the same kind of lip pattern. On the other hand, H. fujianensis showed a lip pattern belonging to type 2 and phylogenetically appears basal to the above-mentioned clade. SEM observation of C. myungsugae showed that the first lip annulus forms a non-projecting uninterrupted disc and the labial annulus is a rectangular shape with slight dorsal and ventral indentations. Phylogenetic relationships among Criconemoides spp. are apparently not well resolved. The present study provides updated morphological descriptions, molecular diagnostics and phylogenetic relationships of H. chitwoodi, H. fujianensis, H. parasinensis, and C. myungsugae, the last species being the first report from China.

The genus Paratrichodorus currently comprises 26 species of polyphagous ectoparasitic plant nematodes that are distributed worldwide and include a few tobravirus vector species. Paratrichodorus is one of the most difficult genera for species identification because it is phenotypically conserved, with morphometric characters that often overlap between species. From 2003 to 2016, nematode surveys were conducted in southern Spain, and the present study addresses 22 nematode populations of the Paratrichodorus hispanus group. Among them, two new species, Paratrichodorus almadenensis sp. nov. and Paratrichodorus ramblensis sp. nov., are described here morphologically and molecularly and compared with topotype specimens of Paratrichodorus hispanus. Furthermore, this analysis was complemented with the first molecular data for this species complex and for the genus Monotrichodorus. The phylogeny of family Trichodoridae showed the relationship of Monotrichodorus with Trichodorus, both of which are phylogenetically associated with the P. hispanus species group, including the two newly described species. Several phylogenetic hypotheses about the monophyly of the genera with molecular data composing the family Trichodoridae were tested using Shimodaira–Hasegawa and approximately unbiased tests. This work also includes the first observations of copulatory plugs in Paratrichodorus, which clearly differ from the different types of mating plugs described in Trichodorus species., This research was supported by grants P12-AGR 1486 and AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Union Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’, grant 219262 ArimNET_ERANET FP7 2012–2015 Project PESTOLIVE ‘Contribution of olive history for the management of soilborne parasites in the Mediterranean basin’ from Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), grant AGL2012-37521 from ‘Ministerio de Economía y Competitividad’ of Spain, and grant 201740E042, ‘Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos’ from the Spanish National Research Council (CSIC). A. J. Archidona-Yuste is a recipient of research contract BES-2013-063495 from ‘Ministerio de Ciencia e Innovación’ of Spain. C. Gutiérrez-Gutiérrez gratefully acknowledges the support of the Prometeo Project from SENESCYT, Ecuadorian Government, and from the Portuguese Foundation for Science and Technology (FCT) through a postdoctoral fellowship (SFRH/ BPD/95315/2013).

This article belongs to the Special Issue The Systematics, Morphological, and Molecular Characterization of Economically Important Plant–Parasitic Nematodes: A Themed Issue in Honor of Dr. Gary Bauchan., Pin nematodes (Paratylenchus spp.) are polyphagous parasitic species with a wide host range and geographical distribution; their diversity is unknown in the potato growing region of Alberta, Canada. The present study aims to provide morphological and molecular characterization of three pin nematode species, namely P. neoprojectus, P. tateae, and a new species, Paratylenchus enigmaticus sp. nov. All of them were recovered from the potato growing region of southern Alberta. The nematodes were isolated using the sieving and flotation-centrifugation method, and their morphology was assessed by light microscopy. Molecular characterization was performed using partial 18S, D2–D3 expansion domains of the 28S and ITS ribosomal genes. This study is the first report of molecular characterization of P. tateae and P. neoprojectus, being new records from southern Alberta, and two Spanish populations of P. tateae comprising the first report of this species in Europe. The phylogenetic analysis of the 18S, D2–D3 expansion domains of the 28S and ITS ribosomal DNA regions underscores the importance of using molecular data for accurate species identification and clarifies the status of P. nanus type B and P. sheri. Moreover, our findings will be useful to determine the impact of pin nematodes on potato production in future field research., This work was supported by the Potato Early Dying Complex project funded by the University of Lethbridge Research Operating Fund, and the Canadian Potato Early Dying Network project funded by the Canadian Agri-Science Cluster for Horticulture 3 grant to D.P.Y., in collaboration with the Potato Growers of Alberta, McCain Foods Canada Ltd., Cavendish Farms Corp. and Lamb Weston Inc.; and by the Spanish Ministry of Science, Innovation and Universities, grant number “RTI2018-095925-A-I00” to P.C. and J.E.P.-R.

Bacterial endosymbionts have been detected in some groups of plant-parasitic nematodes, but few cases have been reported compared to other groups in the phylum Nematoda, such as animal-parasitic or free-living nematodes. This study was performed on a wide variety of plant-parasitic nematode families and species from different host plants and nematode populations. A total of 124 nematode populations (previously identified morphologically and molecularly) were screened for the presence of potential bacterial endosymbionts using the partial 16S rRNA gene and fluorescence in situ hybridization (FISH) and confocal microscopy. Potential bacterial endosymbionts were only detected in nematode species belonging to the genus Xiphinema and specifically in the X. americanum group. Fifty-seven partial 16S rRNA sequences were obtained from bacterial endosymbionts in this study. One group of sequences was closely related to the genus ‘Candidatus Xiphinematobacter’ (19 bacterial endosymbiont sequences were associated with seven nematode host species, including two that have already been described and three unknown bacterial endosymbionts). The second bacterial endosymbiont group (38 bacterial endosymbiont sequences associated with six nematode species) was related to the family Burkholderiaceae, which includes fungal and soil–plant bacterial endosymbionts. These endosymbionts were reported for the first time in the phylum Nematoda. Our findings suggest that there is a highly specific symbiotic relationship between nematode host and bacterial endosymbionts. Overall, these results were corroborated by a phylogeny of nematode host and bacterial endosymbionts that suggested that there was a high degree of phylogenetic congruence and long-term evolutionary persistence between hosts and endosymbionts., This research was supported by grants P12-AGR 1486 and AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Union Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’, grant AGL2012-37521 from ‘Ministerio de Economía y Competitividad’ of Spain, grant 219262 ArimNET_ERANET FP7 2012–2015 Project PESTOLIVE ‘Contribution of olive history for the management of soilborne parasites in the Mediterranean basin’ from Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA). A. J. Archidona-Yuste is a recipient of contract BES-2013-063495 from ‘Ministerio de Ciencia e Innovación’ of Spain.

The Xiphinema americanum-group constitutes a complex of about 55 species of polyphagous plant-ectoparasitic nematodes with a worldwide distribution. This group of plant-parasitic nematodes is one of the most difficult dagger nematode species complexes for diagnosis because the morphology is very conservative and morphometric characters often overlap. We conducted nematode surveys in cultivated and wild olives in southern Spain from 2012 to 2014, from which we identified 16 nematode populations of the X. americanum-group, five of which were tentatively identified as belonging to three new species and are described herein as Xiphinema plesiopachtaicum sp. nov., Xiphinema vallense sp. nov., and Xiphinema astaregiense sp. nov., and 11 populations belonging to nine known species: Xiphinema brevisicum, Xiphinema duriense, Xiphinema incertum, Xiphinema luci, Xiphinema madeirense, Xiphinema opisthohysterum, Xiphinema pachtaicum, Xiphinema parapachydermum, and Xiphinema rivesi. A phenetic study based on multivariate factor analyses was developed to compare some of these related species by using morphometric features. In the factor analysis the first four factors accounted for 73.1% of the total variance of the selected characters, identifying body length, body length/maximum body width (a), body length/pharyngeal length (b), body length/tail length (c), and tail length/body width at anus (c′) ratios, distance from anterior end to vulva as percentage of body length (V), stylet length, oral aperture-guiding ring distance, and lip region width as key morphometric characters to differentiate a restricted set of species within the X. pachtaicum-subgroup that includes X. plesiopachtaicum sp. nov. and X. vallense sp. nov. Multivariate analysis of variance using these specific characters allowed to differentiate species in the X. pachtaicum complex or groups of them using morphometric characters (body length, a, b, c, c′, V, stylet length, lip region width, oral aperture-guiding ring distance, female tail length, and hyaline region length). Phylogenetic analyses based on nuclear ribosomal DNA genes [D2-D3 expansion segments of large ribosomal subunit 28S, and internal transcribed spacer 1 (ITS1)] and the protein-coding mitochondrial gene, cytochrome c oxidase subunit 1 (coxI) were congruent, showing two main clades separating most of the species of X. americanum-subgroup ‘sensu stricto’ from the X. pachtaicum-subgroup. Agreement between phylogenetic trees and some morphological characters (viz. total stylet length, vulva position, and a ratio) were tested by reconstruction of their histories on rRNA-based trees using parsimony and Bayesian approaches. Thus, integrative taxonomy, based on a combination of multivariate morphological and molecular analyses constitutes a new insight into the identification of X. americanum-group species. © 2015 The Linnean Society of London

During a survey on pin nematodes in western Iran, two populations of Paratylenchus audriellus and Paratylenchus tenuicaudatus were collected and subsequently analysed morphologically and molecularly. Paratylenchus audriellus is characterised by the long stylet (48-61 μm) and the typical female tail with a characteristic claw-like process with sharply pointed terminus. To our knowledge, the Iranian population of P. tenuicaudatus is the first record from Iran. The molecular characterisation of P. audriellus nematodes using the D2-D3 of 28S rRNA and the partial 18S rRNA gene sequences revealed that this species is clearly separated from P. straeleni and should be considered as a valid taxon., This study was financially supported by University of Tehran (Project no: 73130662/07/06). Iranian authors would like to thank Mr Shahab Esmaeili for his help during sampling and Dr R. Ghaderi (Shiraz University) for helpful comments. The Spanish authors thank C. Cantalapiedra-Navarrete (IAS-CSIC) for her excellent technical assistance, and grant AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Unión Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’.

The reniform nematodes of the genus Rotylenchulus are semi-endoparasites of numerous herbaceous and woody plant roots and are mainly distributed in tropical and subtropical regions. In this study, we provide morphological and molecular characterisation of six out of ten presently known valid species of Rotylenchulus: R. clavicaudatus, R. leptus, R. macrodoratus, R. macrosoma, R. reniformis and R. sacchari from South Africa, USA, Italy and Spain. Rotylenchulus parvus was only studied morphologically. A new species, R. macrosomoides sp. n., isolated from soil and roots of sugarcane in South Africa, is described. The phylogeny of Rotylenchulus, as inferred from the analyses of D2-D3 of 28S rRNA, ITS rRNA, coxI mtDNA and hsp90 gene sequences, is presented. The study revealed that R. reniformis and R. macrosoma have a sister relationship, but that relationships between other Rotylenchulus species remain unresolved. The phylogenetic analysis also confirmed the hypothesis that this genus originated from the Afrotropical zoogeographical region. Our study revealed that R. reniformis and R. macrosomoides sp. n. have two distinct rRNA gene types and R. macrosoma have three rRNA gene types in their genomes. PCR with species-specific primers was developed for rapid diagnostics of R. reniformis., Pablo Castillo acknowledges support from the grant AGL2012-37521 from the ‘Ministerio de Economía y Competitividad’ of Spain, grant P12-AGR 1486 and grant AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía and Unión Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’ and Sergei A. Subbotin acknowledges support from the Russian Foundation of Basic Research, project number 14-04-00953.

This article belongs to the Special Issue Plant Parasitic Nematodes., Due to Israel’s successful agricultural production and diverse climatic conditions, plant-parasitic nematodes are flourishing. The occurrence of new, previously unidentified species in Israel or of suggested new species worldwide is a consequence of the continuous withdrawal of efficient nematicides. Among plant-parasitic nematodes, migratory endoparasitic species of the genus Pratylenchus are widely distributed in vegetable and crop fields in Israel and are associated with major reductions in quality and yield. This review focuses on the occurrence, distribution, diagnosis, pathogenicity, and phylogeny of all Pratylenchus species recorded over the last few decades on different crops grown throughout Israel—covering early information from nematologists to recent reports involving the use of molecular phylogenetic methodologies. We explore the accepted distinction between Pratylenchus thornei and Pratylenchus mediterraneus isolated from Israel’s northern Negev region, and address the confusion concerning the findings related to these Pratylenchus species. Our recent sampling from the northern Negev revealed the occurrence of both P. thornei and P. mediterraneus on the basis of molecular identification, indicating P. mediterraneus as a sister species of P. thornei and their potential occurrence in a mixed infection. Finally, the efficiencies of common control measures taken to reduce Pratylenchus’ devastating damage in protected crops and field crops is discussed., This research was funded by The Chief Scientist Ministry of Agriculture and Rural Development grant number 131-4544.

Sheath nematodes of the genus Hemicycliophora are migratory root-ectoparasites of many crops, but the damage is documented for only a few species. Hemicycliophora subbotini n. sp., isolated in Hangzhou, Zhejiang, China, from the rhizosphere of camphor tree (Cinnamomum camphora (L.) Presl), is described and characterized morphologically and molecularly with important morphological details elucidated by SEM studies. The new species can be characterized by the conoid lip region, with bulging oral disc protruding beyond the first annulus in some specimens. Oral disc narrow ovate, amphidial apertures covered by lateral plates, lying in the same plane as oral disc when observed en face. Stylet 118 (108–125) μm long and flexible, stylet knobs concave shaped having a slight cavity. The excretory pore is located 1–2 annuli posterior to the base of pharyngeal bulb. Vulval lips slightly modified with small vulval sleeve, spermatheca rounded to oblong. Anus located 18 (15–22) annuli posterior to vulva. Tail elongated, with conoid or slightly offset spike having a narrowly rounded terminus. The study provides the first description of a new Hemicycliophora species from China. Phylogenetic analyses based on D2–D3 expansion segments of the 28S and ITS fragments revealed the new species forming a separate clade from other Hemicycliophora species which supported the status as a new species of this genus., This research was supported by the National Natural Science Foundation of China (No: 31371921 and 31772137).

Hemicycliophora presently contains 132 valid species of sheath nematodes. Within several samples obtained from surveys in Canada, South Africa, Spain and the USA, we distinguished six valid and six putative unidentified species by integrating the results of morphological and molecular analyses. Valid species included: H. californica, H. gracilis, H. parvana, H. poranga, H. raskii, and H. signata. The putative unidentified species were indicated as Hemicycliophora sp. 10, sp. 12, sp. 15, sp. 16, sp. 17, and sp. 18. Two new species of sheath nematodes from Spain and the USA were described and named as H. onubensis sp. n. and H. robbinsi sp. n., respectively. Hemicycliophora wyei is proposed as a junior synonym of H. parvana and H. ripa is proposed as a junior synonym of H. poranga. Eighteen valid and 13 unidentified species of sheath nematodes were characterised using the partial COI mtDNA gene. A total of 94 new sequences of which 77 were for the COI mtDNA gene were obtained in this study. Phylogenetic relationships within Hemicycliophora, using the D2-D3 expansion segments of 28S rDNA, ITS rRNA and COI gene sequences, are presented as inferred from Bayesian analysis., The sixth author thanks financial support from grant 201740E042, ‘Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos’ from the Spanish National Research Council (CSIC).

Sheathoid nematodes of the genus Hemicriconemoides are migratory root-ectoparasites of many crops but damage is documented for only a few species. Hemicriconemoides paracamelliae sp. n., isolated in Hangzhou, Zhejiang, China, from the rhizosphere of Cinninghamia lanceolata, is described together with H. kanayaensis and H. parataiwanensis. These three species are characterised morphologically and molecularly with important morphological details elucidated by SEM photographs. The new species can be characterised by the en face view having a dorsoventrally orientated oral disc with slit-like opening, and the labial plate being composed of two lateral semi-globular shaped projections on the lateral sides of the oral disc. This new species has the first lip annulus expanded and slightly wider than the second, stylet 83 (80-85) μm long, excretory pore located 5-6 annuli posterior to the base of the pharyngeal bulb, vulva slit-like, vulval flaps absent, spermatheca rounded to oblong-shaped, and anus located 5-8 annuli posterior to vulva. The tail is elongated, conoid, with the terminal annuli curving dorsally or ventrally to form a finely rounded tip. The study provides the first record of H. kanayaensis from mainland China, a new host association of H. parataiwanensis, and molecular sequencing data of the 18S, 28S D2-D3 and ITS sequences., This research was supported by the National Natural Science Foundation of China (No. 31772137).

Xiphinema herakliense n. sp. from wild olive and cultivated trees in Vathy Rema and other localities, Heraklion province of Crete, Greece, is described based on morphological and molecular characters. The new species is characterised by having differentiation in the tubular part of the uterus, body length 4.1 (3.3-5.5) mm, odontostyle 149 (135-163) μm long, odontophore 85 (71-98) μm long, female tail dorsally convex-conoid with subdigitate peg, and presence of functional males. The polytomous identification code of the new species is: A4, B2 + 3, C5a, D6(5), E5, F4(5), G3, H2, I3, J5, K5, L2. The new species belongs to morphospecies Xiphinema non-americanum Group 5 characterised by having two equally developed female genital branches with uterine differentiation, presence of pseudo-Z-organ with small granular bodies plus small spines (in low number) and crystalloid bodies along uterus, and a short, rounded tail ending in a peg. Xiphinema herakliense n. sp. appears closely related to X. barense, X. horvatovicae, X. lanceolatum, X. loteni, X. sphaerocephalum and X. thorneanum, from which it may be differentiated morphologically and/or molecularly. The results of the phylogenetic analyses based on the sequences of the D2-D3 expansion regions of the 28S rRNA gene and ITS1 rRNA genes are also supportive of its specific status., The present research was partially funded by grant KBBE 219262 ArimNET-ERANET FP7 2012-2015 Project PESTOLIVE ‘Contribution of olive history for the management of soilborne parasites in the Mediterranean basin’ from Hellenic Agricultural Organization-DEMETER and Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), grant AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Union Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’.

A new bisexual species of Rotylenchusfrom North-western Iran is described and illustrated based on morphological, morphometric and molecular studies. Rotylenchus urmiaensisn. sp. is characterised by having a truncate lip region with irregular longitudinal striation, lateral field areolated only in pharynx region, stylet length 34-40 μm, vulva positioned at 53-61%, and female tail conoid-rounded to dorsally convex-conoid with 5-10 annuli. Rotylenchus urmiaensisn. sp. appears to be similar to R. striaticeps, from which it may be differentiated morphologically by a slightly shorter body length (870-1269 vs1000-1723 μm), shorter stylet (34-40 vs39-50 μm), female tail shape (conoid-rounded to dorsally convex-conoid vsrounded), frequency of males (rare vscommon as abundant as females), shorter spicules (39-43 vs41-50 μm) and phasmid position (varying from three annuli anterior or three annuli posterior to anus vsat level to seven annuli anterior to anus), and molecularly. The results of phylogenetic analyses based on sequences of D2-D3 expansion region of 28S, ITS-rDNA, 18S rDNA, and the partial cytochrome c oxidase subunit 1 ( coxI) mtDNA, confirmed the species differentiation and the close molecular relationship between R. urmiaensisn. sp. and R. striaticeps., The authors acknowledge the University of Zanjan (Iran) for financial support, Dr Majid Pedram from Tarbiat Modares University for his comments, and grant AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Union Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’.

A new species of the genus Ditylenchus, D. persicus n. sp., was collected around the roots of grapevine and is described and illustrated herein based on morphological and molecular studies. The new species is characterised by a body length of 783 (635-928) μm and 689 (670-715) μm in female and male, respectively, delicate stylet 6.2 (5.0-7.0) μm long, six lines in the lateral field, median bulb of pharynx well developed, muscular with crescentic valve, basal pharyngeal bulb pyriform with 10 (8-13) μm long stem extending into intestine, post-vulval uterine sac relatively short, 16 (14-18) μm long, female and male tail elongate-conoid with finely rounded terminus, and bursa covering 65-80% of male tail length. Morphologically, D. persicus n. sp. appears closer to five known species of the genus, namely: D. arachis, D. caudatus, D. clarus, D. myceliophagus and D. nanus. The results of phylogenetic analyses based on sequences of D2-D3 expansion region of 28S rRNA, ITS and partial 18S rRNA genes confirmed the close molecular relationship between D. persicus n. sp. and other Ditylenchus species such as D. myceliophagus, D. africanus, D. arachis, D. destructor and D. halictus., This study was financially supported by the University of Tehran (Project no: 73130662/07/06). The Spanish authors thank C. Cantalapiedra-Navarrete (IAS-CSIC) for her excellent technical assistance, and grant AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Unión Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’.

Stunt nematodes are characterized by phenotypic plasticity, with overlapping morphology and morphometry leading to potential misidentification. Consequently, the application of integrative taxonomic approaches is useful to species delimitation based on a combination of different perspectives, e.g. morphology and DNA sequences. We conducted nematode surveys in cultivated and natural environments in Spain and the USA, from which we identified 18 known species of the family Telotylenchidae and two new taxa within the studied samples. These species were morphologically, morphometrically, and molecularly characterized. The results of light and scanning electron microscopic observations, and molecular and phylogenetic analysis also allowed two new species to be distinguished, described herein as Bitylenchus hispaniensis sp. nov. and Tylenchorhynchus mediterraneus sp. nov. The phylogenetic analysis was carried out using molecular data from nuclear ribosomal DNA genes [D2–D3 expansion segments of the large ribosomal subunit (28S), internal transcribed spacer (ITS), and partial small ribosomal subunit (18S)]. We also provide here a test of alternative hypotheses that confirms the monophyly of both Tylenchorhynchus and Bitylenchus sensu Siddiqi's classification but does not support Fortuner & Luc's conceptual view of Tylenchorhynchus as a large genus. Ancestral state reconstructions of several diagnostic morphological characters using a maximum parsimony approach showed congruence in morphological and molecular evolution for stylet knob inclination and tail tip annulation. Our analysis emphasizes some of the problems related to the taxonomy and phylogeny of nematodes of Telotylenchinae. © 2014 The Linnean Society of London

The genus Hemicycliophora (Nematoda: Hemicycliophoridae) contains 132 valid species of plant-parasitic nematodes, collectively known as ‘sheath nematodes’. Hemicycliophora spp. are characterized morphologically by a long stylet with rounded basal knobs and a cuticular sheath, present in juvenile and adult stages. Populations of 20 valid and 14 putative species of Hemicycliophora and Loofia from several countries were characterized morphologically using light (LM) and scanning electron microscopy (SEM) and molecularly using the D2-D3 segments of 28S rRNA and internal transcribed spacer (ITS) rRNA gene sequences. LM and SEM observations provided new details on the morphology of these species. PCR-restriction fragment length polymorphisms (PCR-RFLPs) of the D2-D3 of 28S rDNA were proposed for identification of the species. Phylogenetic relationships within populations of 36 species of the genus Hemicycliophora using 102 D2-D3 of 28S rDNA and 97 ITS rRNA gene sequences as inferred from Bayesian analysis are reconstructed and discussed. Ancestral state reconstructions of diagnostic characters (body and stylet length, number of body annuli, shape of vulval lip and tail), using maximum parsimony and Bayesian inference, revealed that none of the traits are individually reliable characters for classifying the studied sheath nematode. The Shimodaira–Hasegawa test rejected the validity of the genus Loofia. This is the most complete phylogenetic analysis of Hemicycliophora species conducted so far. © 2014 The Linnean Society of London

This research was supported by a grant AGL2009-06955 from ‘Ministerio de Ciencia e Innovacion’ of Spain, grant 219262 ArimNET_ERANET FP7 2012–2015 Project PESTOLIVE ‘Contribution of olive history for the management of soilborne parasites in the Mediterranean basin’ from Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA), grant AGL2012-37521 from 'Ministerio de Economia y Competitividad' of Spain, grant AGR-136 from ‘Consejeria de Economia, Innvovacion y Ciencia’ from Junta de Andalucia, and the European Social Fund.

A new species of the genus Nothotylenchus, N. persicus n. sp. was collected around the roots of grapevine and is described and illustrated herein based on morphological and molecular studies. The new species is characterised by a body length of 776-900 μm, delicate stylet 5-6 μm long, six lines in the lateral field, post-vulval uterine sac short, 10-18 μm long, female tail elongate-conoid with pointed terminus, and bursa covering 40-45% of tail length. Morphologically, N. persicus n. sp. appears closer to four known species of the genus, namely: N. hexaglyphus, N. affinis, N. medians and N. taylori. The results of phylogenetic analyses based on sequences of D2-D3 expansion region of 28S rRNA gene confirmed the close molecular relationship between N. persicus n. sp. and other anguinids, but Nothotylenchus claded separately from Ditylenchus species., This study was financially supported by University of Tehran. The authors thank C. Cantalapiedra-Navarrete (IAS-CSIC) for her excellent technical assistance, and grant AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Unión Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’.

This is the first report of Hoplotylus femina in Spain. It was collected from the rhizosphere and roots of common alder (Alnus glutinosa) in La Alberca, Salamanca Province, in Spain. The morphology and morphometrics of the Spanish population of H. femina agree closely with the original description of the species and other descriptions from The Netherlands, USA, New Zealand, Poland, Japan and Mexico. Only small differences in some morphological characters were found probably due to geographical intraspecific variability and/or different methods of fixing nematodes. This study provides new molecular markers for species identification (D2-D3 expansion regions of 28S and ITS-rRNA genes) and a new phylogenetic position for the D2-D3 region marker. Maximum likelihood analysis using the Shimodaira-Hasegawa test did not support the inclusion of Radopholus and Hoplotylus in the Pratylenchidae and both genera were more related phylogenetically to Hoplolaimidae., The authors thank J. Martin Barbarroja and G. León Ropero (IAS-CSIC) for their excellent technical assistance, and grant AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Unión Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’.

Aphelenchoides iranicus n. sp. is described and illustrated from bark samples of an oak tree (Quercus sp.) in West Azerbaijan province, north-western Iran. The new species is characterised by body length of 350 (330-383) μm in females and 343 (323-370) μm in males, lip region set off from body contour, lateral fields with three lines, stylet 8 (7-9) μm long with small basal swellings, excretory pore 59 (56-62) μm from anterior end, hemizonid invisible, pharyngeal glands overlapping intestine dorsally and extending for 48 (41-54) μm, female tail subcylindrical with many tiny finger-like appendages at the tip, and male with aphelenchoid type spicules 17.6 (17-18) μm long. The new species comes close to nine known species of the genus namely: A. brevicaudatus, A. cibolensis, A. conimucronatus, A. editocaputis, A. montanus, A. pusillus, A. rarus, A. sphaerocephalus and A. vaughani, but differs from them by the number of incisures in the lateral field, shape of tail mucron, stylet length, size of spicules and length of post-vulval uterine sac. Additionally, this species is characterised molecularly and phylogenetically by sequences of the D2-D3 expansion segments of the 28S and partial 18S rRNA genes that are unique in relation to the sequences deposited in GenBank., This study was financially supported by the University of Tehran. The Spanish authors thank C. Cantalapiedra-Navarrete (IAS-CSIC) for her excellent technical assistance, and grant AGR-136 from ‘Consejería de Economía, Innvovación y Ciencia’ from Junta de Andalucía, and Unión Europea, Fondo Europeo de Desarrollo regional, ‘Una manera de hacer Europa’.

Xiphinema granatum n. sp. from pomegranate in Saveh, Markazi province, central Iran, is described and illustrated. The new species belongs to species group 8 of the genus Xiphinema sensu Loof & Luc, 1990. The new species is characterised by a body 3.5-4.1 mm long, 37-49 μm diam., odontostyle and odontophore 118-132 and 65-74 μm long, respectively, presence of sperm in the female genital tracts, uterus devoid of any Z-differentiation or spines, and abundant males with spicules 45-58 μm long. The polytomous identification codes of the new species are: A4, B4, C5a, D5, E56, F4, G23, H2, I3, J4, K2, L2. Beside morphological and morphometric data, molecular analyses of D2-D3 fragments of 28S rRNA gene placed the new species in close relationship with X. vuittenezi and X. italiae and some species belonging to Xiphinema morphospecies group 6, but clearly separated from X. index. In addition, an Iranian population of Longidorus pisi from the same locality is morphologically and molecularly characterised., The authors thank Mohammad Reza Atighi, Azam Houshmand and Farideh Moharrek for their kind help and the Iranian National Science Foundation (INSF) and Tar- biat Modares University (Iran) for financial support, and the excellent technical assistance of J. Martín Barbarroja (IAS-CSIC). The Spanish authors thank the Consejería de Economía, Innovación y Ciencia from the Junta de An- dalucía (grant AGR-136) and the European Social Fund for financial support.

{null=Two new amphimictic species, Rotylenchus iranicus n. sp. and R. conicaudatus n. sp., are described. Rotylenchus iranicus n. sp. is characterised mainly by an offset hemispherical lip region with 5-6, rarely 7, annuli, stylet 39-44 μm long, vulva located at 53-65% and rounded tail with 4-9 annuli and typical smooth tip. Morphologically this species is related to R. montanus, R. provincialis and R. aqualamus. Rotylenchus conicaudatus n. sp. is characterised mainly by a slightly offset conoid-rounded lip region with four or five, rarely six annuli, stylet 27-32 μm long, vulva located at 52-63% and conoid-rounded tail with 10-16 annuli and a typical annulated tip. Morphologically this species is related to R. pumilus, R. abnormecaudatus, R. acuspicaudatus and R. provincialis. The results of the phylogenetic analysis based on sequences of the D2-D3 expansion regions of 28S and ITS1-rRNA genes confirmed the species differentiation. Phylogenetic relationships with other species were difficult to assign using D2-D3 expansion regions of 28S. However, using ITS1-rRNA, R. conicaudatus n. sp. presented a close relationship with R. unisexus, whilst R. iranicus n. sp. was closely related to R. conicaudatus n. sp., R. unisexus, R. incultus and R. laurentinus., en= Two new amphimictic species, Rotylenchus iranicus n. sp. and R. conicaudatus n. sp., are described. Rotylenchus iranicus n. sp. is characterised mainly by an offset hemispherical lip region with 5-6, rarely 7, annuli, stylet 39-44 μm long, vulva located at 53-65% and rounded tail with 4-9 annuli and typical smooth tip. Morphologically this species is related to R. montanus, R. provincialis and R. aqualamus. Rotylenchus conicaudatus n. sp. is characterised mainly by a slightly offset conoid-rounded lip region with four or five, rarely six annuli, stylet 27-32 μm long, vulva located at 52-63% and conoid-rounded tail with 10-16 annuli and a typical annulated tip. Morphologically this species is related to R. pumilus, R. abnormecaudatus, R. acuspicaudatus and R. provincialis. The results of the phylogenetic analysis based on sequences of the D2-D3 expansion regions of 28S and ITS1-rRNA genes confirmed the species differentiation. Phylogenetic relationships with other species were difficult to assign using D2-D3 expansion regions of 28S. However, using ITS1-rRNA, R. conicaudatus n. sp. presented a close relationship with R. unisexus, whilst R. iranicus n. sp. was closely related to R. conicaudatus n. sp., R. unisexus, R. incultus and R. laurentinus. }

This research, part of the PhD project of the first author, was supported by grants P06-AGR-01360 from ‘Consejeria de Innovacion Ciencia y Empresa’ of Junta de Andalucia, AGL2008-00344 and AGL2009-06955 from ‘Ministerio de Ciencia e Innovacion’ of Spain and the European Social Fund.

UNLABELLED PREMISE OF THE STUDY Seedling establishment and early survivorship are crucial steps for the regeneration of plant populations because both have long-lasting effects on plant population dynamics. For species recruiting through facilitation, species-specific facilitative effects might affect early fitness, an overlooked aspect in studies of facilitation considering groups of nurse species. • METHODS We experimentally evaluated the roles of 10 nurse species and open space on the early performance of the columnar cactus Neobuxbaumia mezcalaensis. We measured establishment, survivorship, and growth of individuals over 3 years. Moreover, to study an extended period of the ontogeny of the interaction between this cactus and its nurse plants, we also monitored survivorship and growth rates of individuals between 3 to 12 cm tall during a 3-year period. • KEY RESULTS Neobuxbaumia mezcalaensis performance varied significantly among nurse species, and only six yielded positive effects on early fitness. Densely canopied plants were the best nurses for this cactus. However, even among densely canopied species, some produced negative effects on the early fitness of N. mezcalaensis, indicating that similar nurse plants may elicit either facilitative or interference effects on beneficiary species. • CONCLUSIONS Our results emphasize the importance of species-specific facilitative interactions in the crucial early stages in the life cycle of N. mezcalaensis and how different nurse species modify the effect of seed-rain and contribute significantly to the population dynamics of the species.

During recent nematode surveys in a muddy soil around undetermined graminaceous plants in El Rocío, Huelva Province, in southern Spain, and from the rhizosphere of date palm associated with graminaceous vegetation from Abadan, in Khuzestan Province, south-west Iran, populations of Longidorus orientalis were identified. Morphological and morphometrical studies on these populations fit the original description and represent the first report from Spain and Europe. Molecular characterisation of L. orientalis from Spain and Iran, using D2-D3 expansion regions of 28S rRNA, 18S rRNA and ITS-rRNA, is provided. Sequences of the D2-D3 expansion regions and partial 18S genes were analysed using maximum likelihood and Bayesian inference to reconstruct phylogenetic relationships within L. orientalis and other Longidorus species. The results revealed a closer phylogenetic relationship with L. goodeyi for the D2-D3 expansion region and with L. vineacola for the partial 18S region.

Needle nematode populations of Longidorus orientalis associated with date palm, Phoenix dactylifera, and detected during nematode surveys conducted in Arizona, California and Florida, USA, were characterised morphologically and molecularly. The nematode species most likely arrived in California a century ago with propagative date palms from the Middle East and eventually spread to Florida on ornamental date palms that were shipped from Arizona and California. This is the first validated continental record of this needle nematode species in the USA and the Americas. The USA populations of L. orientalis contained a small number of males that were not reported in the original description and are herein described. Longidorus orientalis was able to survive for at least 4 years at very low numbers in the warm and humid environment of Florida on date palms imported from California and Arizona. Association of L. orientalis with L. africanus was observed in all of the surveyed sites, indicating that date palm is a host of both nematodes. Phylogenetic relationships of L. orientalis with closely related Longidorus species, in addition to relationships between populations of L. orientalis from the USA, Greece, Iran and Spain, were inferred from the analyses of D2-D3 of 28S rRNA, ITS1 rRNA and partial coxI gene sequences. The PCR-D2-D3 expansion segments of 28S rDNA-RFLP diagnostic profile is provided. Longidorus orientalis populations display a high level of intraspecific variation (up to 15.5%) in coxI mtDNA sequences. Analysis of phylogenetic relationships of nematode populations revealed incongruence of the ITS1 rRNA and coxI mtDNA gene trees, which might be the result of selective introgression of mtDNA through gene flow between previously isolated populations introduced simultaneously into new geographical regions.