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Reniform nematodes of the genus Rotylenchulus are semi-endoparasites of numerous herbaceous and woody plant species roots and occur largely in regions with temperate, subtropical, and tropical climates. In this study, we provide new records of the nematode Rotylenchulus macrosoma in eight European countries (Czech Republic, France, Germany, Hungary, Italy, Romania, Serbia, and Portugal), in addition to the six Mediterranean countries (Greece, Israel, Jordan, Spain, Syria, and Turkey) where the nematode was previously reported. Four new host species (corn, pea, wheat, and an almond-peach hybrid rootstock) are added to the recorded host species (bean, chickpea, hazelnut, peanut, soybean, and wild and cultivated olive). Molecular analyses based on the cytochrome c oxidase subunit coxI and D2-D3 segments of 28S RNA markers showed high diversity and pronounced genetic structure among populations of Rotylenchulus macrosoma. However, the complexity of phylogeographic patterns in plant-parasitic nematodes may be related to the intrinsic heterogeneity in the distribution of soil organisms, a rare occurrence of a species, or the potential human impact associated with agricultural practices., Financial support was provided by the Spanish National Research Council (grant 201740E042, “Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos”), the Spanish Ministry of Economy and Competitiveness (“Ramon y Cajal” Fellowship” RYC-2017-22228 to J. E. Palomares-Rius), the Ministerio de Ciencia, Innovación y Universidades (grant RTI2018-095925-A-100), the Helmholtz Centre for Environmental Research (UFZ) (Humboldt Research Fellowship for Postdoctoral Researchers to A. Archidona-Yuste), and the China Scholarship Council (to R. Cai).

Needle nematodes are polyphagous root-ectoparasites parasitizing a wide range of economically important plants not only by directly feeding on root cells, but also by transmitting nepoviruses. This study deciphers the diversity of the complex Longidorus goodeyi through integrative diagnosis method, based on a combination of morphological, morphometrical, multivariate analysis and molecular data. A new Longidorus species, Longidorus panderaltum n. sp. is described and illustrated from a population associated with the rhizosphere of asphodel (Asphodelus ramosus L.) in southern Spain. Morphologically, L. panderaltum n. sp. is characterized by having a moderately long female body (5.2-7.0 mm), lip region bluntly rounded and slightly offset by a depression with body contour, amphidial pouch with slightly asymmetrical lobes, odontostyle 80.5–101.0 µm long, tail short and conoid rounded. Longidorus panderaltum n. sp. is quite similar to L. goodeyi and L. onubensis in major morphometrics and morphology. However, differential morphology in the tail shape of first-stage juvenile, phylogeny and haplonet analyses indicate they are three distinct valid species. This study defines those three species as members of L. goodeyi complex group and reveals the taxonomical complexity of the genus Longidorus. This L. goodeyi complex group demonstrated that the biodiversity of Longidorus in this region is still not fully clarified., This research was financially supported by grant 201740E042, “Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos” from Spanish National Research Council (CSIC), and by the Humboldt Research Fellowship for Postdoctoral Researchers awarded for the corresponding author. The first author acknowledges the China Scholarship Council (CSC) for financial support. The fifth author acknowledges Spanish Ministry of Economy and Competitiveness for the “Ramon y Cajal” Fellowship RYC-2017-22228. The corresponding author is a recipient of Humboldt Research Fellowship for Postdoctoral Researchers at Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany. Open Access funding provided by Projekt DEAL.

Needle nematodes have an economic importance by causing damage to a wide range of natural and cultivated plants not only by directly feeding on root cells, but also by transmitting plant nepoviruses. Two new Longidorus nematodes, Longidorus oakcrassus n. sp. and Longidorus oakgracilis n. sp., are described and illustrated from populations associated with the rhizosphere of Pyrenean oak (Quercus pyrenaica Wild.) in southern Spain. The taxonomic position of both new species within the genus was assigned using an integrative approach. Morphologically, L. oakcrassus n. sp. is characterized by a female with a large and robust body size (9.2–12.2 mm), lip region anteriorly flattened to slightly rounded and almost continuous or slightly offset by a depression with body contour, ca 25.5–32.0 μm wide, amphidial fovea with slightly asymmetrical lobes, stylet composed by an odontostyle moderately long (110.0–133.5 μm) and odontophore weakly developed, pharynx short ending in a terminal pharyngeal bulb with common arrangement of pharyngeal glands, tail short almost hemispherical shape. Longidorus oakgracilis n. sp. is characterized by having a moderately long and thin female body (5.4–7.9 mm in length), a bluntly-rounded lip region, set off from body contour by a slight depression, amphidial fovea funnel-shaped without lobe, odontostyle moderately long (94.0–106.0 μm), pharyngeal bulb with common arrangement of pharyngeal glands, short tail, bluntly hemispherical. The presence of males is common in both species. Integrative diagnosis was based on molecular data using D2-D3 expansion domains of the 28S rRNA, 18S rRNA, ITS1 rRNA and partial coxI gene sequences and morphology. Although different gene markers show variations in the phylogenetic relationships, phylogeny indicated that L. oakcrassus n. sp. is phylogenetically related with several species described from the Iberian Peninsula, including L. oakgracilis n. sp., which is clustered with L.cf. olegi, L. lusitanicus and L. silvestris., This research was financially supported by grant 201740E042, “Análisis de diversidad molecular, barcoding, y relaciones filogenéticas de nematodos fitoparásitos en cultivos mediterráneos” from Spanish National Research Council (CSIC). Authors thank G. León Ropero and J. Martín Barbarroja (IAS-CSIC) for the excellent technical assistance. 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 Discocriconemella sinensis n. sp. isolated in Hangzhou, Zhejiang, China, from the rhizosphere of Camellia sinenis is described. The new species was characterised morphologically and molecularly. Important morphological details were elucidated by SEM photographs. The new species is characterised by an uninterrupted rounded cephalic disc, en face showing a rectangular labial plate with slit-like oral apertures, labial plate surrounded by slightly elevated projections resembling rudimentary lobes, R = 66 (64-69), Rex = 21 (17-24), stylet 74 (67-81) μm long, excretory pore located at the base of the pharyngeal bulb, vulva open, tail short and conoid with a lobed terminus. The species belongs to the group 1 lip pattern. Morphologically, it is most similar to D. discolabia, D. mauritiensis, D. mineira and D. perseae. This is the first new Discocriconemella species described from China. Phylogenetic analyses based on analysis of the D2-D3 expansion segments of the 28S rRNA, ITS rRNA, partial 18S rRNA, and COI gene revealed that the new species formed a separate clade from other criconematid species, thereby supporting its status as a new species of the genus. The new species showed close relationships with Criconemoides informis.

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.

Reniform nematodes of the genus

Ring nematodes of the genus Criconemoides are a group of polyphagous, migratory root-ectoparasites of plants. In a nematological survey of Zhejiang Province, three new Criconemoides species were isolated from the rhizosphere of Citrus sp., Euonymus alatus and Pterocarya stenoptera trees. In the present study, the new species characterized using an integrative taxonomic approach and described as Criconemoides parainformis n. sp., C. geraerti n. sp. and C. rotundicaudatus n. sp. Three of the species shares truncated anteriorly flattened lip region comprised of two annuli, body annuli margin smooth with few anastomoses, (except C. rotundicaudatus n. sp. it has crenated annuli margins and numerous anastomoses), excretory pore 1–2 annuli posterior to pharyngeal bulb base, (except C. geraerti n. sp. it has excretory pore at the same level, or 1–2 annuli anterior to pharyngeal bulb base), vulva closed, anus hardly visible 1–3 annuli posterior to vulva. The new species can be distinguished based on their en face view pattern under scanning electron microscope (SEM) and the tail shapes. i.e. C. parainformis n. sp. has an ellipsoid oral disc, slightly fused pseudolips and tail ending in a bilobed terminus. C. geraerti n. sp. has a hexagonal oral disc, separated pseudolips, and a bluntly conoid tail. C. rotundicaudatus n. sp. has a rounded oral disc, well developed pseudolips, and a short broadly rounded tail. Besides detailed morphological studies using SEM, genomic and mitochondrial molecular data were obtained for the three described new species. In inferred phylogenies, these three species clustered with known Criconemoides species in 18S, 28S, ITS and coxI trees. Currently, only four known Criconemoides species occur in China and the discovery of the three new Criconemoides species in present study has increased our knowledge on the diversity of Criconemoides in China., This research was supported by the National Natural Science Foundation of China (No:31772137).

Xiphinema hangzhouensesp. n. is described from the rhizosphere ofMagnolia grandiflorain Hangzhou, China. The new species is characterised by having a monodelphic reproductive system, slim body, total stylet = 186-192μm long and vulva located anteriorly at 27.6-31.2% of total body length. The new species has a gonad 400-450μm long with a simple uterus and no Z-organ. The female tail is elongated conoid with a rounded terminus. The species has four juvenile stages and no male was found. The polytomous identification codes ofX. hangzhouensesp. n. are A1, B4, C2, D23, E12, F2, G2, H2, I23, J2, K2, L1. The new species is morphologically similar toX. winotoi. Phylogenetic analyses of the 28S rRNA, ITS rRNA, 18S rRNA and partialCOIgene sequences ofX. hangzhouensesp. n. and some closely relatedXiphinemaspecies revealed that the new taxon clustered with high statistical support withX. radicicolaandX. setariae.

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.

Three populations of Xiphinema non-americanum group species were detected in agricultural and natural ecosystems, during routine surveys for plant-parasitic nematodes in Spain. Based on morphological and molecular analyses, the species were identified as Xiphinema histriae and Xiphinema lapidosum, being this the first record and molecular characterization of both species in Spain. The morphometrics and morphology of the Spanish populations agree with those of the original description and paratype specimens and the present study provided a first description of the second to fourth juvenile stages of both species. A detailed study on the morphology in the Spanish populations of X. histriae, as well as in paratypes, showed a pseudo-Z-organ with weakly muscularized wall and containing numerous small dense granular bodies, which was different to the original description by Lamberti et al. (1993). This new finding suggests that X. histriae must be considered a member of the morphospecies Group 5 of X. non-americanum. Phylogenetic analysis based on D2 to D3 expansion segments of 28S gene, ITS1 and partial CoxI gene indicated that X. histriae and X. lapidosum are phylogenetically related with other Xiphinema non-americanum group spp. reported from Spain. Considering the pathological and economic importance of this group of nematodes, the combination of morphological characters, measurements, and molecular analysis is crucial for accurate identification of these species., 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 (CSIC).

The Family Criconematidae is commonly referred as ring nematodes that include some members with economic importance as plant parasites. During a recent nematode inventory survey at Zhejiang Province, China, a new species of genus Nothocriconemoides was detected in the rhizosphere of elm tree. Nothocriconemoides hangzhouensis n. sp. can be characterized by the female body having annuli with fine longitudinal striations and 2 to 3 anastomoses at the posterior half of the body. The first cephalic annulus is rounded and expanded enclosing the lip region, and the second annulus is narrow, offset, collar like. En face view shows a central elevated labial disk bearing four distinct equal-sized submedian lobes and “I” shaped oral aperture. Excretory pore is located 3–4 annuli posterior to esophageal bulb. Vagina is straight and vulva closed. The ventral side of postvulval annuli is inverted, in majority of individuals. Anus is indistinct and located on the next annuli posterior to vulva. Tail is short, conoid, with forked or branched terminus. Juveniles are devoid of collar-shaped annuli in the lip region. The cephalic region has two rounded annuli where the first annulus shows slight depression in the middle. Body annuli are finely crenated. Anus is indistinct and located 3 to 4 annuli from tail terminus. Tail is short ending in a single lobed terminus. Phylogenetic studies based on analysis of the D2–D3 expansion segments of the 28 S rRNA, ITS rRNA, partial 18 S rRNA, and coxI gene revealed that the new species formed a separate clade from other criconematid species, thereby supporting its status as a new species of the genus. The new species showed close relationships with Discocriconemella sinensis. Additionally, this is the first record of genus Nothocriconemoides from China., This research was supported by the National Natural Science Foundation of China (No: 31772137).

The family Longidoridae Thorne, 1935 comprises a group of migratory plant-parasitic species that damage a wide range of wild and cultivated plants through direct feeding on root cells and the transmission of several plant-pathogenic viruses (Decraemer and Robbins, 2007; Decraemer and Chaves, 2012). Members of these genera are known to transmit nepoviruses and are regulated by quarantine inspections in many countries (Gutiérrez-Gutiérrez et al., 2016). Longidorus and Paralongidorus belong to family Longidoridae, both are globally distributed and have 160 and 90 known species, respectively (Palomares-Rius et al., 2013; Archidona-Yuste et al., 2016; Esmaeili et al., 2016). Some species of Paralongidorus have controversial status due to synonymization of Longidoroides (Khan et al., 1978) and Siddiqia (Khan et al., 1978), and some Paralongidorus species have been wrongly included and belong to genus Longidorus (Decraemer and Coomans, 2007). The major difference used to separate Longidorus, Longidoroides, and Paralongidorus is the shape of amphids (pouch like in Longidorus and Longidoroides vs. funnel/stirrup shaped in Paralongidorus) and the opening of amphidial aperture (pore-like in Longidorus vs. slit-like in Longidoroides and Paralongidorus) (Oliveira and Neilson, 2006). Several new species of Paralongidorus have published with complete molecular characterization and scanning electron microscopy (SEM) observations (Palomares-Rius et al., 2008, 2013; Pedram et al., 2012; Gutiérrez-Gutiérrez et al., 2017; Barsi and Luca, 2017) which enables the discrimination between Longidorus and Paralongidorus species. However, there is no molecular evidence to distinguish Longidoroides species which leaves the status of this genus as junior synonym of Paralongidorus as suggested by Decraemer and Coomans (2007). During a routine nematological survey of Hangzhou, Zhejiang Province, eastern China, two populations of longidorid nematodes were isolated from the rhizosphere of woody perennials. The population isolated from Cyclobalanopsis glauca (Thumb.) Oerst, 4 juvenile stages were recovered and identified as Longidorus jonesi, the population from Castanopsis sclerophylla (Lindl.) Schottky, 3 juvenile stages were recovered and was identified as Paralongidorus sali. Robbins et al. (1995) reported 3 juveniles stages of L. jonesi and no first stage juvenile or male were observed additionally this is the first report of genus Paralongidorus found in China. Therefore, the objectives of the present study were to: (i) provide updated morphological descriptions of first-stage juvenile P. sali, and male of L. jonesi, (ii) characterize the molecular data of both species using the D2–D3 expansion segments of 28S rRNA and partial 18S rRNA gene sequences, and (iii) demonstrate the phylogenetic relationships of both species with related species., This research was supported by the National Natural Science Foundation of China (No: 31772137).

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).

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).

The above-mentioned paper was submitted with an incomplete address for the authors Ruihang Cai and Munawar Maria. The correct address should be as follows