A new species of the genus Hexamermis Steiner, 1924 (Nematoda: Mermithidae) from northern Iran: a nematode with an unusual uterine morphology.

Hexamermis zirabi sp. n., recovered from a natural habitat of Mazandaran province, north of Iran, is described based on morphological and molecular data. The new species is characterized by its six cephalic papillae; cuticle with distinct cross fibers; conoid or sharply tapered head; mouth terminal; six hypodermal cords; J-shaped vagina oriented to the anterior end of body; uterus with Z-organs or sclerotized bodies; tail similar in both sexes and bluntly rounded; spicules paired, separate, slightly curved, shorter than body width at cloaca, with rounded tip; and male genital papillae arranged in five rows. In addition to the morphological study, molecular phylogenetic analyses using a partial large subunit (28S D2-D3) were also performed, and the new species formed a highly supported (1.00% Bayesian posterior probability (BPP)) clade with Hexamermis popilliae.

Laimydorus zehsaziani n. sp., a new member of the genus from northwest of Iran, with additional data on Labronema vulvapapillatum (Meyl, 1954) Loof & Grootaert, 1981 (Dorylaimida: Dorylaimidae).

A new species belonging to the genus Laimydorus, and a known species of the genus Labronema, collected from the rhizosphere of grassland plants in West Azarbaijan province, Iran, are presented. The new species is characterized by its body length (1.56-1.81 mm in females and 1.39-1.57 mm in males), lip region offset by weak constriction and wider than adjacent body (11-14 µm), odontostyle 17-20 µm long, neck length 312-434 µm, vulva longitudinal (V = 42.2-46.5), uterus well-developed and with Z-differentiations, tail long (219-237 µm, c = 6.9-8.3, c´ = 8.2-10) in females, short and convex-conoid with blunt terminus (19-22 µm, c = 68-72.5, c´= 0.77-0.84) in males, spicules 40-45 µm long, and 18-20 contiguous ventromedian supplements with hiatus. Molecular analyses, using Bayesian inference based on D2-D3 expansion segments of the 28S rRNA (LSU), placed the new species in a clade comprising representatives of the genera Nevadanema, Dorylaimus, Labronema, Calcaridorylaimus, Mesodorylaimus, and Prodorylaimus, which all belong to Dorylaimidae. In addition, new data (molecular, morphometrics, images, and geographic distribution) are presented for the Iranian population of Labronema vulvapapillatum.

Study of two species, one new and one known, of the genus Aporcella Andrássy, 2002 (Dorylaimida, Aporcelaimidae) from Iran, with a note on its phylogeny.

Two species of the genus Aporcella, one new and one previously known, collected from cultivated fields in Iran are studied. Description, morphometrics, illustrations (both line and microphotographs) and D2-D3 sequences are provided for Aporcella talebii sp. n., which is characterized by its 1.66-2.02-mm-long body, lip region offset by constriction and 15-17 µm broad, odontostyle 14-17.5 µm long, neck 412-484 µm long, pharyngeal expansion occupying 46-50% of total neck length, uterus simple and 1.6-2.0 times the corresponding body diameter long, V = 52-59, tail conical (40-50 µm, c = 37-47, c' = 1.1-1.4) with a weak but perceptible dorsal concavity at the end and male absent. Morphometrics, microphotographs and D2-D3 sequences of Aporcella simplex are also presented, this being its first Asian record. Molecular analyses confirm the monophyly of the genus, its close relationship with other taxa lacking pars refringens vaginae and the polyphyly of Aporcelaimidae.

Eudorylaimus kahaqensis sp. n. (Nematoda: Dorylaimida: Qudsianematidae), an interesting new species from Iran.

A new species of the genus Eudorylaimus is described from Kahaq region, Maragheh, East Azarbaijan province in Iran. Eudorylaimus kahaqensis sp. n. is characterized by its 1.40-1.75 mm long body, lip region nearly continuous and 17-21 µm wide and bearing a weakly sclerotized but distinct cephalic framework, cheilostom broad and with convex walls, odontostyle 21-23 µm long with aperture occupying 33-44% of its length, presence of a dorsal coelomocyte a short distance behind the nerve ring, neck 347-397 µm long, DN rather posterior (66-70%), pharyngeal expansion 162-205 µm or occupying 45-53% of total neck length, presence a dorsal cell mass at level of pharyngo-intestinal junction, V = 48-52, caudal region conical elongate (50-73 µm, c = 24-30, c' = 1.9-2.6 in females; 45-68 µm, c = 22-32, c' = 1.7-2.3 in males) and regularly curved ventrad with large hyaline portion, spicules 48-55 µm long and 7-9 irregularly spaced ventromedian supplements lacking hiatus.

Metaxonchium persicum sp. n. from Iran (Nematoda, Dorylaimida, Belondiridae), with an updated taxonomy of the genus.

A new species of the genus Metaxonchium is described from natural habitats in Iran. The new species is characterized by having body length of 2.46-3.12 mm, lip region offset by constriction and 8-11 µm wide, odontostyle fusiform and 10-12 µm long, neck 773-1150 µm long, anterior portion of pharynx bearing a spindle-shaped thickening with valve-like structures inside, both parts of the pharynx separated by a short isthmus-like narrowing, pharyngeal expansion 531-825 µm long and occupying up to three-fourths of total neck length, female genital system monodelphic-opisthodelphic, anterior genital branch reduced to a large uterine sac and a small terminal mass, posterior uterus long and tripartite with an intermediate region bearing apophyses, V = 53-57, caudal region conoid with broadly rounded terminus (24-35 µm, c = 79-105, c' = 0.6-0.9), spicules 92-103 µm long and 7-10 spaced ventromedian supplements, at least two of them within the range of spicules. The taxonomy of the genus Metaxonchium is updated, including a list of its species, a key to their identification and a compendium of their morphometrics. Four species are transferred from Axonchium to Metaxonchium: M. coxi, M. japonicum, M. mizukuboi and M. zealandicum.

Hemocyte responses of the Colorado potato beetle, Leptinotarsa decemlineata, and the greater wax moth, Galleria mellonella, to the entomopathogenic nematodes, Steinernema feltiae and Heterorhabditis bacteriophora.

Hemocyte encapsulation reactions of infective juveniles of two Iranian isolates of the entomopathogenic nematodes, Heterorhabditis bacteriophora Poinar (Rhabditina: Heterorhabditidae) and Steinernema feltiae Filipjev (Tylenchina: Steinernematidae), were compared in the economic pest Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae), and the greater wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae). The former was a more responsive host than the latter and the hemocyte responses occurred sooner and more extensively. Complete encapsulation of some of the nematodes occurred by 4 h post injection for H. bacteriophora in both L. decemlineata and G. mellonella, and by 2 h pi for S. feltiae in L. decemlineata. The percentage of encapsulation from 24 h to 72 h pi in L. decemlineata was 86.2% for S. feltiae and 39% for H. bacteriophora. In G. mellonella there were no encapsulation or melanization responses against S. feltiae, whereas when H. bacteriophora was encapsulated and melanized (16.7%) the encapsulation level was lower than in L. decemlineata. This study may contribute to effectively selecting entomopathogenic nematode species active against significant economic pests based on the latter's cellular immune response.

Morphological and molecular characterization of Paractinolaimus sahandi n. sp. (Nematoda: Actinolaimidae) from the Sahand Mountains in Iran.

Paractinolaimus sahandi n. sp., found in wet soil samples collected from the rhizosphere of grasses of Sahand Mountains, Iran, is described. This new species is characterized by its long body (3.5-4.7 mm), high a value (74.5-88.5), anterior location of posterior subventral nuclei, occupying 62.5-68.0% of glandularium distance, the presence of 1-4 pre- and 1-3 post-vulval papillae and numerous tiny, not innervated papillae in front and behind the vulva in the outer layer of cuticle; common functional males in the population, with 62.5-81.3 µm long spicules and 15-17 ventromedian supplements. The new species, which is the only one in the genus showing the advulval cuticular tiny papillae and is unusually slender, is compared to four species of Paractinolaimus, namely P. macrolaimus, P. longidrilus, P. spanithelus and P. rafiqi. The ribosomal 18S rDNA (1246 bp sequenced) and 28S rDNA D2/D3 region (844 bp sequenced) of P. sahandi n. sp. were sequenced for molecular characterization. Sequences of the 18S and 28S D2/D3 of P. sahandi n. sp. have distinct differences from those of the only sequenced P. macrolaimus, with 6 bp differences in 18S and 38 bp differences and five gaps in 28S. This is the first report of the occurrence of members of Actinolaimidae in Iran.

First Record of Trichodorus primitivus and Morphological and Molecular Identification of Longidorus elongatus from Canada.

During July 2008, sandy loam soil samples were collected near the rhizosphere of Kentucky bluegrass (Poa pratensis L.) and tall fescue (Festuca arundinacea Schreb.) at a depth of 15 to 20 cm from Caledonia Park, Toronto, Canada. Samples were suspended in water and nematodes were collected on sieves with 250- and 74-µm openings. Among the nematodes recovered were one species of Longidorus Micoletzky, 1922 (4) and one species of Trichodorus Cobb, 1913. The Trichodorus species (2), was identified as T. primitivus (de Man, 1880) Micoletzky, 1922, in which females have rod-like sclerotized pieces parallel to the vagina lumen, each with dimensions of 3.1 × 1.2 µm and at a distance of 2 to 3 µm from each other; and males have spicules with a wide nonoffset capitulum and very narrow blade, three ventromedian cervical papillae (CP), and three precloacal supplements with the anterior one at the level of the capitulum of retracted spicules. Males showed unusual variation in the position of CP2 (i.e., posterior to the onchiostyle region, except for one specimen with CP2 located within the posterior onchiostyle region, which is typical for the species). The morphometric data for nine males are: L, 665 to 805 µm; a, 23.0 to 27.5; b, 3.7 to 5.2; c, 46 to 56; onchiostyle, 47 to 52 µm; and spicules, 32.5 to 40.5 µm. Measurements for 13 females are: L, 630 to 775 µm; a, 20.5 to 24.8; b, 3.5 to 5.5; c, 75.5 to 158.5; and V, 54 to 61%. To our knowledge, this is the first report of T. primitivus in Canada. According to Chen et al. (1), the Longidorus species was identified as L. elongatus (de Man, 1876) Micoletzky, 1922 (3). The morphometric data for females (n = 13) are: L, 5.1 to 6.0 mm; a, 78.5 to 106.5; b, 11.5 to 13.5; c, 86.0 to 120.5; V, 45.5 to 53.0%; odontostyle, 79 to 91 µm; odontophore, 57.5 to 66.5 µm; and tail length, 44.5 to 59.0 µm. Males were not found. Four juvenile stages were identified. J1 (n = 2) with a body length of 1.1, 1.2 mm and replacement/functional odontostyle 59, 59/53.5, 54.5 µm, J2 (n = 2) with L: 1.7, 2.0 mm and replacement/functional odontostyle 62.5, 68.0/58.7 µm, 59.0, J3 (n = 2): L: 2.8, 3.0 mm and replacement/functional odontostyle 76.5, 77/66.5, 67.0 µm and J4 (n = 2) with L: 3.6, 3.8 mm and replacement/functional odontostyle 87.0, 90.5/75.0, 77.5 µm. Due to large morphometric overlap in Longidorus species identification, 2,472 bp of the near full-length 18S and the internal transcribed spacer 1 region of rDNA (Accession No. GU199044) were sequenced. The Blastn search of the partial 18S revealed 100% identity with a population of L. elongatus from Scotland (GenBank No. AY687992, 1,707 bp compared), 99% identity (3 bp difference, 1,707 bp compared) with a population of L. elongatus from Iran (EU503141) and 99% identity (4 bp difference, 1,707 bp compared) with a population of L. elongatus (AF036594, sample location unknown). A Blastn search of the 18S and ITS region revealed only 1 to 3 bp differences with two populations of L. elongatus from Switzerland (AJ549986 and AJ549987) and a population of L. elongatus (AF511417) from Scotland. These molecular data further confirmed the identity of the population from Canada to be L. elongatus. References: (1) Q. Chen et al. Fundam. Appl. Nematol. 20:15, 1997. (2) W. Decraemer. Kluwer Academic Publishers, Dordrecht, the Netherlands, 1995. (3) J. G. de Man. Tijdschr. Ned. Dierk. Ver. 2:78, 1876. (4) H. Micoletzky. Archiv. Naturgesch. 87:1, 1922.