Description of Nothotylenchus savadkoohensis n. sp. (Rhabditida, Anguinidae) from Iran based on morphological and molecular data.

Nothotylenchus savadkoohensis n. sp. was recovered from rotten wood samples of an unidentified forest tree in the Mazandaran province and described herein. It is mainly characterized by an elongated conoid tail ending in a sharply pointed tip and four lines in the lateral field. Females of the new species have 379-662 µm long bodies with 5.8-6.9 µm long stylets ending in fine posteriorly sloping knobs, the metacorpus not valvate, the pharyngeal bulb slightly overlapping the intestine, and the vulva at 76.5-84.0% of body length. Males are also common and have 13.0-14.5 µm long spicules and bursa cloacal. By having an elongated conoid tail and four lines in the lateral field, the new species comes close to four known species, namely N. acris, N. acutus, N. antricolus, and N. truncatus. The morphological differences between the new species and the abovementioned species are discussed. The new species was sequenced for its D2-D3 segment of LSU and ITS rDNA regions. In the LSU phylogenetic tree, the currently available LSU sequences of the genus Nothotylenchus occupied distant placements from each other and the LSU sequence of the new species formed clade with a sequence assigned to Neotylenchus sp. In ITS phylogeny, the newly generated sequence of the new species formed a clade with a clade that includes sequences of Ditylenchus sp. and Neomisticius platypi and N. variabilis.

Morphological and Molecular Characterization of Ottolenchus isfahanicus n. sp. (Tylenchomorpha: Tylenchoidea) from Rhizosphere of Gramineous Plants in Isfahan Province, Iran.

A new species from the family Tylenchidae was recovered in the grasslands of Isfahan province, Iran, and is herein described based on morphological and molecular data. Ottolenchus isfahanicus n. sp. is mainly characterized by having a faintly annulated cuticle; elongated, slightly sigmoid amphidial apertures developed metacorpus with distinct valve under LM; vulva located at 69.472.3% of body length; large spermatheca about 2.75 times of corresponding body width; and elongated conoid tail with broadly rounded tip. SEM observations showed that the lip region is smooth; the amphidial apertures are elongated, slightly sigmoid slits; and the lateral field is a simple band. It is further characterized by 477-to-515-µm-long females with delicate 5.7-to-6.9-µm-long stylets with small, slightly posteriorly sloping knobs, as well as functional males, in the population. The new species closely resembles O. facultativus, but is separated from it based on morphological and molecular data. It was further morphologically compared with O. discrepans, O. fungivorus, and O. sinipersici. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using near-full-length sequences of small subunit and D2-D3 expansion segments of large subunit (SSU and LSU D2-D3). In the inferred SSU phylogeny, the newly generated sequence of Ottolenchus isfahanicus n. sp. formed a clade with two sequences of O. sinipersici and sequences assigned to O. facultativus and O. fungivorus. In the inferred LSU phylogeny, the three newly generated sequences of the new species and LSU sequences of O. sinipersici and O. discrepans formed a clade.

Morphological and Molecular Characterization of Filenchus multistriatus n. sp. (Tylenchomorpha: Tylenchidae) and Data on a Known Species of the Genus from Bushehr Province, Southern Iran.

During a nematological survey in southern Iran, a population belonging to the family Tylenchidae was recovered from a tomato field in Bushehr province. The recovered population belongs to the genus Filenchus, was described and illustrated herein as F. multistriatus n. sp. It is mainly characterized by having a wide and low annulated lip region continuous with adjacent body; amphidial openings confined to the labial plate; four lines in lateral fields forming three bands, with the two outer bands broken by transverse, and the inner one broken by both transverse and longitudinal lines; and median bulb oval with visible valve and elongate-conoid tail uniformly and gradually narrowing toward the distal region, ending in a widely rounded tip. Its morphological and morphometric differences with three closely similar species were discussed. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using partial sequences of small, and large subunit ribosomal DNA (SSU and LSU rDNA) sequences. Morphometric and morphological data were also provided for an Iranian population of F. sandneri recovered from Bushehr province. Both populations were characterised using SEM data.

Deladenus Bonabensis n. Sp. (Tylenchomorpha: Neotylenchidae) from East Azarbaijan Province, Northwestern Iran: A Morphological and Molecular Phylogenetic Study.

A population of Deladenus, representing a new species, was recovered from Bonab's Ghara-Gheshlagh lagoon. It is mainly characterized by having a long body (1051-1185 µm), long distance of anterior end to pharyngeal glands end (270-312 µm), six lines in lateral fields, and a short mucro-like differentiation on the tail tip. Furthermore, it has a small-sized stylet (8.5-11.0 µm) with three knobs, no postvulval uterine sac, and males with 24- to 28-µm-long tylenchoid spicules and penial tube. With six lateral lines, the new species is comparable with seven species of the genus: D. apopkaetus, D. brevis, D. cocophilus, D. durus, D. obtusicaudatus, D. processus, and D. ulani. It was furthermore compared with D. oryzae with an unknown number of lateral lines and D. aridus, D. obesus, and D. parvus having a different number of lateral lines but similar morphology. In the molecular phylogenic analyses using small and large subunit ribosomal DNA (SSU and LSU D2-D3 rDNA) sequences, the relationships of the new species with other species and genera were not resolved in SSU phylogeny. However, it formed a clade with Deladenus sp. and D. brevis in LSU phylogeny.

Erratum to: Morphological and Molecular Characterization of Filenchus multistriatus n. sp. (Tylenchomorpha: Tylenchidae) and Data on a Known Species of the Genus from Bushehr Province, Southern Iran.

[This corrects the article DOI: 10.2478/jofnem-2023-0008.].

Description of Boleodorus Bushehrensis n. Sp. (Rhabditida: Tylenchidae) from Southern Iran, and Observations on a Commonly Known Species.

A new species of the genus Boleodorus, recovered from southern Iran, is described and illustrated based upon morphological and molecular data. B. bushehrensis n. sp. is mainly characterized by having a wide and low cephalic region (which is continuous with the adjacent body), the oral aperture in a depression in side view under a light microscope, four lines in the lateral field, weak metacorpus with a vestigial-to-invisible valve, and short (26-38 mm long) hooked tail with rounded tip. The females are 334-464 mm long and have a spherical spermatheca filled with spheroid sperm; males have 11.5- to 12.0-mm-long spicules and weakly developed bursa. The new species has an annulated low cephalic region, four large cephalic papillae, and small crescent-shaped amphidial openings when observed by scanning electron microscopy (SEM). Its morphological and morphometric differences with seven known species are discussed. The phylogenetic relationships of the new species with other relevant genera and species have been studied using partial sequences of small and large subunit ribosomal DNA (SSU and LSU rDNA). In both the SSU and LSU phylogenies, the sequences of B. bushehrensis n. sp. and other Boleodorus spp. formed a clade. A second species, B. thylactus, when studied under SEM, has a raised, smooth cephalic region, four large cephalic papillae, and oblique amphidial slits, with the oral opening in a depression.

Penetration and Development of Meloidogyne Javanica on Four Pistachio Rootstocks and their Defense Responses.

Pistachio yield is annually reduced due to root-knot nematode infections. In order to evaluate its resistance to Meloidogyne javanica, three domestic pistachio rootstocks, namely, Badami, Ghazvini and Sarakhs, and a wild pistachio, Baneh (Pistacia atlantica subsp. mutica), were selected. Their response to the nematode infection was evaluated based on different plant and nematode indexes, 120 days post-inoculation (dpi). The penetration and development rate of nematode in roots of these four pistachio rootstocks were evaluated at different time points by acid fuchsin staining. Based on the measured indexes, Badami, Ghazvini, Sarakhs, and Baneh rootstocks ranked as susceptible, moderately resistant, moderately resistant, and resistant, respectively. The penetration rate of second-stage nematode juveniles (J2) into four rootstocks was discussed. The first "midstage" or swollen juveniles appeared at 4 dpi but to a lesser extent in Ghazvini, Sarakhs, and Baneh cultivars. The first females were seen in Badami at 21 dpi, in Ghazvini and Sarakhs at 35 dpi, and in Baneh at 45 dpi. Three types of defense responses were distinguished and characterized in the examined pistachio rootstocks: (i) a hypersensitive response (HR)-like reaction in the cortex in Ghazvini, Sarakhs, and Baneh root tips at 4 dpi and 6 dpi; (ii) an HR response, degrading J2 which induce giant cells in the vascular cylinder of all rootstocks, at 6 dpi and 10 dpi; and (iii) an HR response, degrading females and giant cells in the vascular cylinder of all rootstocks at 15 dpi onward. These observations open new fields of study in breeding programs of this crop.

Morphological and molecular characterization of Filenchus pseudodiscus n. sp. from east Golestan province, north Iran; with an updated phylogeny of Malenchus Andrássy, 1968 (Tylenchomorpha: Tylenchidae).

During a survey in Golestan province, north Iran, two populations belonging to the family Tylenchidae were recovered in association with Quercus sp., and a rotten wood sample of an unidentified forest tree. The first recovered species was mainly characterized by having a disc-like differentiation in the frontal end under the light microscope (LM), proposing it as a tentative member of the genus Discotylenchus. Detailed morphological studies using scanning electron microscope (SEM), however, did not reveal a true disc, but showing the smooth cephalic region, and a narrow annulus behind the cephalic plate. Based upon the cephalic region structure, and by lacking a true disc, the species was identified as a member of the genus Filenchus. This population was further characterized by 555 to 618 µm long females, lateral fields with four incisures, 9 to 10 µm long stylet, spermatheca large, including spheroid sperm, post-vulval uterine sac (PUS) 8 to 12 µm long and gradually tapering to an elongate conoid tail with pointed tip. It was compared with relevant species of Filenchus having four incisures in the lateral fields and similar general morphology. By having a disc-like differentiation in the frontal end under the LM, it was further compared with three similar known species of Discotylenchus. The morphological comparisons with species under two aforementioned genera showed the recovered population belongs to an unknown species, described herein as Filenchus pseudodiscus n. sp. The molecular phylogenetic relationships of the new species using partial small and large subunit ribosomal RNA gene (SSU and LSU D2-D3 rDNA) sequences were reconstructed and discussed. Malenchus gilanensis, the second recovered and studied species was originally established based upon traditional criteria. An updated LSU phylogeny of the genus Malenchus by including M. gilanensis was also presented and its results were discussed.

Laimaphelenchus africanus n. sp. (Tylenchomorpha: Aphelenchoididae) from South Africa, a morphological and molecular phylogenetic study, with an update to the diagnostics of the genus.

A newly recovered population of the genus Laimaphelenchus from a dead maritime pine wood sample in Potchefstroom, South Africa, representing a new species, named L. africanus n. sp., is herein described and illustrated based on morphological and molecular data. The new species is mainly characterized by the following: 750-987 µm long females; a cephalic region with no disc and six cephalic lobs not divided by ribs; a 10.0-12.5 µm long stylet; four incisures in the lateral field; secretory-excretory pore (SE-pore) at slightly posterior to the nerve ring; vulva with a well-developed anterior flap, vagina with two well-developed sclerotized pieces; post-vulval uterine sac (PUS) 63-125 µm long; tail conical, 30-44 µm long, ventrally curved with a subventral stalk in terminus, lacking tubercles, with six to nine small projections at the tip in scanning electron microscopy (SEM); and rare males with 17 µm long spicules. The new species was morphologically compared to those species of the genus with a stalk in tail terminus, lacking tubercles, a vulval flap and four incisures in the lateral field viz., L. liaoningensis, L. preissii, L. simlaensis, L. sinensis, L. spiflatus, and L. unituberculus. Phylogenetically, the new species was placed into the major Laimaphelenchus clade using partial large subunit ribosomal DNA (LSU rDNA D2-D3) sequences. An overall literature review corroborated the presence of the stalk (currently with two main groups) at the tail end is the main characteristic trait delimiting the genus. A compendium based on the characters of the stalk, presence/absence of a vulval flap in females and number of the lateral lines was also established.

Description of Longidorella (Saevadorella) caspica n. sp. (Dorylaimida: Nordiidae) from north Iran.

This contribution provides the morphological and molecular identification of a new species of the genus Longidorella (Saevadorella). L. (S.) caspica n. sp., was recovered from the rhizospheric soil of grasses in Mazandaran province in the seashore of the Caspian Sea. It is characterized by females with a length of 788 to 874 µm and a cephalic region with prominent papillae; and separated from the rest of the body by a remarkable constriction, an odontostyle of 32 to 33 µm, vulva at 52.5 to 59.0%, and a tail of 33 to 38 µm with a rounded tip. Males have 32 to 35 µm long spicules of dorylaimoid form and five to seven ventral supplements ending at 48 to 55 µm distance from cloacal pair. The new species was morphologically compared with seven nominal species viz. L. (S.) arenicola, L. (S.) cuspidata, L. (S.) magna, L. (S.) perplexa, L. (S.) saadi, L. (S.) saevae, and L. (S.) tharensis. It was further compared with similar species under the subgenus Longidorella (Enchodorella) viz. L. (E.) deliblatica and L. (E.) murithi. Besides morphological studies, molecular phylogenetic studies using partial sequences of D2 to D3 expansion fragments of 28S rDNA were performed for the new species and its phylogenetic relationships with other species and genera were discussed.

First record of Oscheius myriophilus () (Rhabditida: Rhabditidae) from Iran; and its efficacy against two economic forest trees pests, Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae) and Hyphantria cunea () (Lepidoptera: Erebidae) in laboratory condition.

The box tree moth (BTM), Cydalima perspectalis and the fall webworm (FWW), Hyphantria cunea are two invasive pests of forest trees that have been recorded from Hyracinan forests in north Iran for the first time in 2016 and 2002, respectively. In a search for tentative native entomopathogenic nematode species (EPNs) with potential biocontrol ability against lepidopteran pests of forest trees in north Iran, Oscheius myriophilus was isolated by soil-baiting method from forests of Amlash in the east of Gilan province. The Iranian isolate of this species is characterized by 870-1,247 µm long hermaphrodites having 17-20 µm long stoma, vulva at 45.5-53.1% of body length, tail 90-126 µm long, common males with 38-49 µm long spicules and 583-791 µm long dauer larvae. Compared to the type and other populations, no remarkable differences were observed for this population. The phylogenetic affinities of this isolate with other rhabditid nematodes were studied using partial sequences of small, and the D2-D3 expansion segments of the large subunit ribosomal DNA (SSU and D2-D3 LSU rDNA). This is the first record of the species from Iran. The pathogenicity of Iranian isolate of O. myriophilus was evaluated on the larvae of two important aforementioned forest trees pests, BTM and FWW under laboratory conditions. The results indicated that the suspension of 500 infective juveniles per ml (IJs/ml) of the nematode was the most effective treatment on fifth instar larvae of BTM and FWW, causing 100 and 95% mortality after 48 h, respectively. The lethal concentration 50 (LC50) values of the nematode were 74.5, 152.7, 99.9, and 197.3 IJs/ml on fifth and fourth instar larvae of BTM, and fifth and fourth instar larvae of FWW, respectively, after 48 h at 25°C and 60% relative humidity. Together, present results corroborated the efficacy of the Iranian isolate of Oscheius myriophilus for biocontrolling of BTM and FWW in laboratory conditions.

Description of Deladenus brevis n. sp. (Sphaerularioidea: Neotylenchidae) from Iran: a morphological and molecular phylogenetic study.

Deladenus brevis n. sp. is described and illustrated based upon its morphological, morphometric, and molecular characters. The new species is mainly characterized by its small body size (367-454 µm long females and 350, 391 µm long males) and has small lateral vulval flaps. It is further characterized by having six lines in the lateral fields, cephalic region slightly expanded, narrower adjacent to the body, short 6 to 7 µm long stylet with three posteriorly sloped knobs, no post-vulval uterine sac (PUS), conical tail, narrowing to a rounded tip, and rare males with slender tylenchoid spicules and bursa reaching the tail tip. By having six lines in the lateral fields, the new species was compared with five known species of the genus, namely D. apopkaetus, D. cocophilus, D. durus, D. obtusicaudatus, and D. persicus, having comparable number (six or seven) of lines in the lateral fields. It was further compared with D. pakistanensis having lateral vulval flaps. The differences with above-mentioned species are discussed. In molecular phylogenetic analyses using nearly full length small and large subunit ribosomal DNA (SSU and LSU D2-D3 rDNA) and cytochrome c oxidase subunit I (COI mtDNA) gene sequences, D. brevis n. sp. formed clade with species of the genus with different clade support values in Bayesian inference.Deladenus brevis n. sp. is described and illustrated based upon its morphological, morphometric, and molecular characters. The new species is mainly characterized by its small body size (367-454 µm long females and 350, 391 µm long males) and has small lateral vulval flaps. It is further characterized by having six lines in the lateral fields, cephalic region slightly expanded, narrower adjacent to the body, short 6 to 7 µm long stylet with three posteriorly sloped knobs, no post-vulval uterine sac (PUS), conical tail, narrowing to a rounded tip, and rare males with slender tylenchoid spicules and bursa reaching the tail tip. By having six lines in the lateral fields, the new species was compared with five known species of the genus, namely D. apopkaetus, D. cocophilus, D. durus, D. obtusicaudatus, and D. persicus, having comparable number (six or seven) of lines in the lateral fields. It was further compared with D. pakistanensis having lateral vulval flaps. The differences with above-mentioned species are discussed. In molecular phylogenetic analyses using nearly full length small and large subunit ribosomal DNA (SSU and LSU D2-D3 rDNA) and cytochrome c oxidase subunit I (COI mtDNA) gene sequences, D. brevis n. sp. formed clade with species of the genus with different clade support values in Bayesian inference.

Morphological and molecular characterization of Ektaphelenchoides pini () (Aphelenchoididae; Ektaphelenchinae) from Iran, with morphological and taxonomic observations on some species.

Ektaphelenchoides pini, the type species of the genus Ektaphelenchoides, was recovered from wood and bark samples of a dead broadleaf forest tree collected from the forests of Golestan province in north of Iran. The recovered population is mainly characterized by massive wide spicules of males with well-developed condylus marked by indentations at the apex and simple distal tip. It was further characterized by 756 to 947 µm long females having a cephalic region slightly separated from the rest body by a shallow depression, 20 to 23 µm stylet with wide lumen lacking conophore and knobs, excretory pore (E pore) at about one metacorpus length behind it, or 92 to 106 µm from anterior end and hemizonid just posterior to it, vagina anteriorly inclined, post uterine sac (PUS) ca 1.2 times vulval body width long, posterior body region elongate conoid, ending to a filiform tip, no functional rectum, a vestigial anus and common males with dorsally convex tail ending to an elongate spike and two pairs of precloacal (P2) and caudal (P3) large papillae at 5 to 6 µm distance anterior to cloacal opening and 30 to 41% of tail, respectively and lacking the single precloacal papilla (P1). In molecular phylogenetic analyses using small and large subunit ribosomal DNA (SSU, LSU rDNA) sequences, the Iranian population of E. pini fell in a clade including species of three genera Ektaphelenchus, Ektaphelenchoides, and Devibursaphelenchus in SSU, and a clade including species of Ektaphelenchus and Ektaphelenchoides in LSU tree, in close association with an isolate identified as E. pini in the latter phylogeny with high (0.99) Bayesian posterior probability (BPP). The comparisons with the type and French populations, as well as phylogenetic affinities of the species using ribosomal data, are discussed. This is the first report of E. pini from Iran, and its first simultaneous morphological and molecular phylogenetic study. New observations on some species of the genus were also presented and discussed.Ektaphelenchoides pini, the type species of the genus Ektaphelenchoides, was recovered from wood and bark samples of a dead broadleaf forest tree collected from the forests of Golestan province in north of Iran. The recovered population is mainly characterized by massive wide spicules of males with well-developed condylus marked by indentations at the apex and simple distal tip. It was further characterized by 756 to 947 µm long females having a cephalic region slightly separated from the rest body by a shallow depression, 20 to 23 µm stylet with wide lumen lacking conophore and knobs, excretory pore (E pore) at about one metacorpus length behind it, or 92 to 106 µm from anterior end and hemizonid just posterior to it, vagina anteriorly inclined, post uterine sac (PUS) ca 1.2 times vulval body width long, posterior body region elongate conoid, ending to a filiform tip, no functional rectum, a vestigial anus and common males with dorsally convex tail ending to an elongate spike and two pairs of precloacal (P2) and caudal (P3) large papillae at 5 to 6 µm distance anterior to cloacal opening and 30 to 41% of tail, respectively and lacking the single precloacal papilla (P1). In molecular phylogenetic analyses using small and large subunit ribosomal DNA (SSU, LSU rDNA) sequences, the Iranian population of E. pini fell in a clade including species of three genera Ektaphelenchus, Ektaphelenchoides, and Devibursaphelenchus in SSU, and a clade including species of Ektaphelenchus and Ektaphelenchoides in LSU tree, in close association with an isolate identified as E. pini in the latter phylogeny with high (0.99) Bayesian posterior probability (BPP). The comparisons with the type and French populations, as well as phylogenetic affinities of the species using ribosomal data, are discussed. This is the first report of E. pini from Iran, and its first simultaneous morphological and molecular phylogenetic study. New observations on some species of the genus were also presented and discussed.

Cephalenchus driekieae n. sp. (Nematoda: Tylenchidae) from South Africa, a new member of the genus with a long pharyngeal overlap.

Cephalenchus driekieae n. sp. is described and illustrated based on its morphological, morphometric, and molecular characteristics. This new species is mainly characterized by its short stylet 11.5 to 13.0 µm, and 13.5 to 17.5 µm long pharyngeal overlap extending over the intestine. It could further be delimited by 451 to 526 µm long females with a prominently annulated cuticle, dorso-ventral amphidial openings as shown using scanning electron microscopy (SEM), four lines in the lateral field, anchor-shaped stylet knobs, empty spermatheca, elongate conoid tail with finely rounded tip and males absent. The shortest stylet and long pharyngeal overlap, distinguish this new species from previously described members and update the characteristics of the genus. With four lines in the lateral field, this new species was morphologically compared with four previously described species with this feature and another species with a short stylet. Molecular phylogenetic analyses using the partial small and large subunit ribosomal DNA gene (SSU and LSU rDNA D2-D3) sequences showed that it was clustered with other Cephalenchus spp. in both SSU and LSU trees, retaining the monophyly of the genus. This new species from South Africa updates the biogeography of the genus.Cephalenchus driekieae n. sp. is described and illustrated based on its morphological, morphometric, and molecular characteristics. This new species is mainly characterized by its short stylet 11.5 to 13.0 µm, and 13.5 to 17.5 µm long pharyngeal overlap extending over the intestine. It could further be delimited by 451 to 526 µm long females with a prominently annulated cuticle, dorso-ventral amphidial openings as shown using scanning electron microscopy (SEM), four lines in the lateral field, anchor-shaped stylet knobs, empty spermatheca, elongate conoid tail with finely rounded tip and males absent. The shortest stylet and long pharyngeal overlap, distinguish this new species from previously described members and update the characteristics of the genus. With four lines in the lateral field, this new species was morphologically compared with four previously described species with this feature and another species with a short stylet. Molecular phylogenetic analyses using the partial small and large subunit ribosomal DNA gene (SSU and LSU rDNA D2-D3) sequences showed that it was clustered with other Cephalenchus spp. in both SSU and LSU trees, retaining the monophyly of the genus. This new species from South Africa updates the biogeography of the genus.

Description of Seinura italiensis n. sp. (Tylenchomorpha: Aphelenchoididae) found in the medium soil imported from Italy.

Seinura italiensis n. sp. isolated from the medium soil imported from Italy is described and illustrated using morphological and molecular data. The new species is characterized by having short body (477 (407-565) µm and 522 (469-590) µm for males and females, respectively), three lateral lines, stylet lacking swellings at the base, and excretory pore at the base or slightly anterior to base of metacorpus; females have 58.8 (51.1-69.3) µm long post-uterine sac (PUS), elongate conical tail with its anterior half conoid, dorsally convex, and ventrally slightly concave and the posterior half elongated, narrower, with finely rounded to pointed tip and males having seven caudal papillae and 14.1 (12.6-15.0) µm long spicules. Morphologically, the new species is similar to S. caverna, S. chertkovi, S. christiei, S. hyrcania, S. longicaudata, S. persica, S. steineri, and S. tenuicaudata. The differences of the new species with aforementioned species are discussed. In molecular phylogenetic analyses using near full-length small and large subunit ribosomal DNA (SSU and LSU rDNA D2-D3 expansion segments) sequences, the new species fell into a clade including three previously described/sequenced species of the genus in both SSU and LSU Bayesian phylogenetic trees.Seinura italiensis n. sp. isolated from the medium soil imported from Italy is described and illustrated using morphological and molecular data. The new species is characterized by having short body (477 (407-565) µm and 522 (469-590) µm for males and females, respectively), three lateral lines, stylet lacking swellings at the base, and excretory pore at the base or slightly anterior to base of metacorpus; females have 58.8 (51.1-69.3) µm long post-uterine sac (PUS), elongate conical tail with its anterior half conoid, dorsally convex, and ventrally slightly concave and the posterior half elongated, narrower, with finely rounded to pointed tip and males having seven caudal papillae and 14.1 (12.6-15.0) µm long spicules. Morphologically, the new species is similar to S. caverna, S. chertkovi, S. christiei, S. hyrcania, S. longicaudata, S. persica, S. steineri, and S. tenuicaudata. The differences of the new species with aforementioned species are discussed. In molecular phylogenetic analyses using near full-length small and large subunit ribosomal DNA (SSU and LSU rDNA D2-D3 expansion segments) sequences, the new species fell into a clade including three previously described/sequenced species of the genus in both SSU and LSU Bayesian phylogenetic trees.

Hemicycliophora ahvasiensis n. sp. (Nematoda: Hemicycliophoridae), and data on a known species, from Iran.

Hemicycliophora ahvasiensis n. sp., recovered from the rhizospheric soil of date palm in Khuzestan province, southwest Iran, is described and illustrated based upon morphological, morphometric and molecular data. The new species is characterized by its sheath, closely fitting most of the body, cuticle with or without numerous irregular lines, sometimes appearing as blocks in distal body region. Lateral field without discrete longitudinal lines, but often with continuous broken striae or anastomoses. Continuous lip region with single annulus, slightly elevated labial disc, stylet with posteriorly sloping knobs. Vulva with or without slightly modified lips, spermatheca with sperm and tail conoid, symmetrically narrowing at distal region to form a narrow conical region. Morphologically, the new species looks similar to H. indica, H. labiata, H. siddiqii, H. tenuistriata and H. typica. The latter species appears more similar to the new species under light microscopy, but could be separated using the scanning electron microscopy and molecular data. The new species was also compared with H. epicharoides and H. dulli, two species with close phylogenetic affinities to it. The phylogenetic relationships of the new species were reconstructed and discussed using partial sequences of the D2-D3 expansion segments of large subunit, and internal transcribed spacer regions (LSU D2-D3 and ITS rDNA). Hemicycliophora conida, the second studied species, was recovered from north Iran and characterized by morphological and molecular data.

Labrys khuzestanensis n. sp. (Nematoda, Tylenchidae), a new member of the genus with large labial plate.

Labrys khuzestanensis n. sp. was recovered from the rhizosphere of a palm tree in southwestern Iran and described using morphological and molecular data. The new species was characterized by combination of the following features: its 590-675 µm long body, finely annulated cuticle in light microscopy (LM), lateral field with two smooth incisures, cephalic region dorso-ventrally flattened with protuberant, elongate and laterally extended labial plate, appearing a V-shaped piece in lateral view, amphidial openings as longitudinal slits confined to labial plate in scanning electron microscopic (SEM) images, stylet 7.5-9.0 µm long, elongated fusiform median bulb with faint valvular apparatus, excretory pore wide with moderately sclerotized duct and elongate filiform tail with finely rounded tip. Compared to four currently known species under the genus, the new species has a remarkably larger and more prominent labial plate as revealed by SEM and trapezoid cephalic region under LM. The molecular phylogenetic analyses of the new species using partial SSU rDNA revealed it has close affinity with three species of Labrys (L. chinensis, L. fuzhouensis and L. filiformis) in Bayesian inference (BI) and maximum likelihood (ML) methods and occupied a placement inside their clade. L. fujianensis, the other species of the genus, occupied a distant placement to the aforementioned clade. This is the second species of Labrys being originally described from Iran, representing the third species of Labrys occurring in the country.

New evidence of nematode-endosymbiont bacteria coevolution based on one new and one known dagger nematode species of Xiphinema americanum-group (Nematoda, Longidoridae).

Three populations of Xiphinema primum n. sp. and two populations of X. pachtaicum were recovered from natural forests and cultural regions of northern Iran. Both species belong to the X. americanum-group and were characterized by their morphological, morphometric and molecular data. The new species, which was recovered in three locations, belongs to the X. brevicolle-complex and is characterized by 2124-2981 µm long females with a widely rounded lip region separated from the rest of the body by a depression, 103-125 µm long odontostyle, two equally developed genital branches with endosymbiont bacteria inside the ovary, which are visible under light microscope (LM), vulva located at 51.8-58.0%, the tail is 26-37 µm long with a bluntly rounded end and four juvenile developmental stages. It was morphologically compared with nine similar species viz. X. brevicolle, X. diffusum, X. incognitum, X. himalayense, X. luci, X. parabrevicolle, X. paramonovi, X. parataylori and X. taylori. The second species, X. pachtaicum, was recovered in two geographically distant points close to city of Amol. Molecular phylogenetic studies of the new species were performed using partial sequences of the D2-D3 expansion segments of the large subunit ribosomal RNA gene (LSU rDNA D2-D3), the internal-transcribed spacer rDNA (ITS = ITS1+5.8S+ITS2), and the mitochondrial cytochrome c oxidase I gene (COI mtDNA) regions. The Iranian population of X. pachtaicum was also phylogenetically studied based upon its LSU rDNA D2-D3 sequences. Both species were also inspected for their putative endosymbiont bacteria. Candidatus Xiphinematobacter sp. was detected from two examined populations of the new species, whereas the second endosymbiont bacterium, detected from three examined isolates of X. pachtaicum, was related to the plant and fungal endosymbionts of the family Burkholderiaceae. The phylogenetic analyses of the two endosymbiont bacteria were performed using partial sequences of 16S rDNA. In cophylogenetic analyses, significant levels of cophylogenetic signal were observed using both LSU rDNA D2-D3 and COI mtDNA markers of the host nematodes and 16S rDNA marker of the endosymbiont bacteria.

Two Ektaphelenchinae Paramonov, 1964 (Nematoda: Rhabditida) from Iran have tripartite stylet, with similar observations in other species.

Two ektaphelenchid nematodes representing one new and one known species are illustrated and characterized using morphological and molecular data. Ektaphelenchus kanzakii n. sp. is mainly characterized by its tripartite stylet having a well visible wide lumen, encompassing a sclerotized and acute anterior part (the conus), a short and slightly tapering middle part (the conophore) that is equally sclerotized but clearly separate from the conus, and a long posterior part that is cylindrical and only weakly sclerotized (the shaft) without basal knobs or swellings. It is further characterized by 863.5 (772-926) µm long females having 23.8 (21.2-27.0) µm long total stylet, distinctly annulated cuticle, three lines in lateral field, vulva at 76.6 (75.3-80.0)%, no rectum, vestigial anus in some individuals, conical posterior body end (tail) with narrow ventrally bent tip, common males in population with two pairs of caudal papillae (the single precloacal papilla and the third caudal pair lacking), spicules with dorsally bent tip and conical tail with sharp or blunt tip. The new species is morphologically compared with close species having conical posterior body end and stylet lacking basal knobs or swellings. Iranian population of Devibursaphelenchus teratospicularis, the second studied species, is characterized by 679.5 (620-709) µm long females having 18.6 (17.5-20.0) µm long total stylet with similar structure to the previous species, subcylindrical body end with widely rounded tip, and rare males with typical spicules of this species and a pair of precloacal and a pair of caudal papillae. Molecular phylogenetic studies of the two recovered species using small and large subunit ribosomal DNA (SSU and LSU rDNA) partial sequences revealed they have close phylogenetic affinities with Ektaphelenchus obtusus in both reconstructed trees. However, species of both genera Ektaphelenchus and Devibursaphelenchus don't form monophyletic groups in SSU and LSU trees. New observations on stylet structure of the two presently studied and some other ektaphelenchid species having available light microphotographs (LM) yielded on definition of a new term "conophore" for the middle part of the ektaphelenchid-type tripartite stylet.

Genetic diversity, and description of a new dagger nematode, Xiphinema afratakhtehnsis sp. nov., (Dorylaimida: Longidoridae) in natural forests of southeastern Gorgan, northern Iran.

The most prevalent dagger nematode recovered from rhizospheric soil samples of forest trees in the Afratakhteh region of Golestan province (Iran) was Xiphinema afratakhtehnsis sp. nov. and it is described and illustrated with integrative approaches using both morphological and molecular criteria. It belongs to the morphospecies group 6 of the intragenic historical grouping of Xiphinema non-americanum species. The new species is characterized by females with 3.3-4.9 mm sized body, lip region separated from the rest of body by a depression, anteriorly expanded, 16-18 µm wide, vulva located at 47.2-58.5%, odontostyle 155-173 µm and odontophore 89-107 µm long, female genital system composed of two equally developed branches, the tubular part of each having spines, short symmetrically rounded female tail to symmetrically rounded with a small mucro-like projection at the end in a few females, rare males (n = 1 out of 74 females) with 83 µm long dorylaimoid spicules and four juvenile developmental stages. The third-stage juveniles (J3) have a characteristic tail shape (short, symmetrically conical with a club-shaped long mucro) demarcating the species, and being typologically useful for its separation from closely similar species (except X. cohni, with currently no data on its juvenile stages) viz. X. adenohystherum, X. iranicum, X. mazandaranense, X. nuragicum, X. pyrenaicum, X. robbinsi, X. sphaerocephalum and X. zagrosense. Molecular phylogenetic studies using genomic (partial large subunit and internal transcribed spacer 1 ribosomal RNA genes: D2-D3 and ITS1 rDNA) and mitochondrial cytochrome c oxidase subunit I gene (COI mtDNA) revealed the new species forming a unique lineage in all reconstructed trees using Bayesian inference (BI) and maximum likelihood (ML) methods. The sequenced isolates of the new species formed a monophyletic group in the D2-D3 tree. The sequenced isolates of the new species for their COI mtDNA formed four subclades in COI mtDNA phylogeny, and four haplotypes in corresponding analysis.