Description and SEM Observations of Dolichodorus marylandicus n. sp. With a Key to Species of Dolichodorus

Dolichodorus marylandicus n. sp. is described and illustrated from grass (Zoysia japonica) in College Park, Maryland. Specimens have also been collected from perennial bluegrass (Poa pratensis) pasture at Beltsville, Maryland, and from pine (Pinus sp.) in North Carolina. This new species is related to D. heterocephalus Cobb, D. similis Golden, and D. aestuarius Chow &Taylor. Females are distinct in having a longer styler and shorter body length than D. aestuarius. The excretory pore is at the level of the isthmus or slightly posterior and the tail is abruptly reduced in diameter, tapering to an acuminate terminus. The tails of D. similis and D. heterocephalus conically taper to a median point, with D. similis having an especially long tail. D. marylandicus does not possess the rounded, sclerotized accessory structures adjacent to the vulva observed in lateral views of D. similis and D. heterocephalus. SEM observations of D. heterocephalus and D. marylandicus revealed details of the head of males and females, and species difference in shape of the oral disc.     

Steinernema scapterisci n. sp. (Rhabditida: Steinernematidae)

Steinernema scapterisci n. sp., isolated in Uruguay from the mole cricket Scapteriscus vicinus, can be distinguished from other members in the genus by the presence of prominent cheilorhabdions, an elliptically shaped structure associated with the excretory duct, and a double-flapped epitygma in the first-generation female. The spicules of the male are pointed, tapering smoothly to a small terminus, and the shaft (calomus) is long, bearing a sheath. The gubernaculum has a long, upward-bent anterior part. The ratio of head to excretory pore divided by tail length of the third-stage juvenile is greater for S. scapterisci n. sp. than for S. carpocapsae. Steinernema scapterisci n. sp. did not hybridize with S. carpocapsae strain Breton. In laboratory tests, S. scapterisci n. sp. killed 10% or less of non-orthopteran insects, including the wax moth larva, a universal host for other species of Steinernema.     

Three New Species of the Super Family Neotylenchoidea (Nematoda: Tylenchida) from Pakistan

Three new species in the super family Neotylenchoidea collected in Pakistan during 1979-80 are described. New species Nothotylenchus gohleni is related to N. affinis Thorne, 1941 but is differentiated by its longer, more robust body with tine cuticular annules, a more posterior vulva, inconspicuous basal knobs of the stylet, and poorly developed metacorpal area. N. geraerti and N. tuberosus are also close to this undescribed species, hut they have a more developed metacorpal area and a larger post uterine sac. Boleodorus zaini n.sp. is distinguished by its excretory pore open at a level with the base of the posterior esophageal bulb and by six distinct lines in the lateral field. Paurodontella sohailai n.sp. is closely related to P. densa (Thorne, 1941) Hussain &Khan, 1967 and P. minuta Hussain &Khan, 1967 but differs from them by its larger body, shape of tail, and seven incisures in the lateral field.     

Meloidogyne trifoliophila n. sp. (Nemata: Meloidogynidae), a Parasite of Clover from Tennessee

Meloidogyne trifoliophila n. sp. is described from white clover collected at Ames Plantation, Fayette County, Tennessee. The perineal pattern is rounded, with long, smooth striae and rounded arch, and without distinct lateral lines or perivulval striae. The female stylet is 12.6-15.5 μm long, the excretory pore is level with or up to one stylet length posterior to the stylet knobs, and the vulva is subterminal. The posterior terminus is weakly protuberant. The male lateral field is composed of approximately eight repeatedly broken or forked incisures. The male stylet is 17.0-18.9 μm long, the stylet knobs are rounded and sloping, gradually merging with the shaft, and the head region consists of one large annule. Second-stage juveniles are 357-400 μm long, with a stylet length of 11.9-13.6 μm and one head annule. The tail tapers to a slender tip. This new species is similar to M. graminicola and M. triticoryzae but differs from them in perineal pattern and lateral field morphology, and numerous morphometric characters.     

Description of Dolichodorus cobbi n. sp. (Nematoda: Dolichodoridae) with Description of Dolichodorus cobbi n. sp. (Nematoda: Dolichodoridae) with Morphometrics and Lectotype Designation of D. heterocephalus Cobb, 1914

Dolichodorus cobbi n. sp. is described and illustrated from soil around roots of "woods" on the Stanley Farm, Scott County, Arkansas. This species is distinguishable from others of the genus by its short tail projection. It is most closely related to D. marylandicus but differs in having a short tail projection, longer stylet, greater body length, larger c value, and also in position of excretory pore. A limited number of Cobb''s original specimens and drawings of D. heterocephalus were examined. A lectotype and paralectotype were designated to establish the taxonomic base for the genus. Cobb''s original modified labeled drawing of D. heterocephalus is also included. Morphometric data on D. heterocephalus from the type locality and several other populations are given. Some variations in female tail shape, body length, and stylet length were noted.     

Two new genera of nematode (Oxyurida,Hystrignathidae) parasites of Passalidae (Coleoptera) from the Democratic Republic of Congo

Two new genera and species parasitizing passalid beetles from the Democratic Republic of Congo are described. Kongonema meyeri gen. n. sp. n. is characterized by having females with the cervical cuticle unarmed, first cephalic annule cone-like and truncate, sub-cylindrical procorpus and genital tract didelphic-amphidelphic. The males of Kongonema meyeri gen. n. sp. n. have the procorpus sub-cylindrical, the dorsal cuticle of the tail end thickened, a single large, median mammiform pre-cloacal papilla and a pair of small, pre-cloacal, sub-lateral papillae at a short distance before the level of the cloaca. Lubanema decraemerae gen. n. sp. n. is characterized by the body markedly fusiform, cuticle unarmed and strongly annulated, procorpus sub-cylindrical, isthmus as a constriction between procorpus and basal bulb, genital tract monodelphic-prodelphic and the posterior end rounded with a very short tail appendage.     

Lipocalin signaling controls unicellular tube development in the Caenorhabditis elegans excretory system

Unicellular tubes or capillaries composed of individual cells with a hollow lumen perform important physiological functions including fluid or gas transport and exchange. These tubes are thought to build intracellular lumina by polarized trafficking of apical membrane components, but the molecular signals that promote luminal growth and luminal connectivity between cells are poorly understood. Here we show that the lipocalin LPR-1 is required for luminal connectivity between two unicellular tubes in the Caenorhabditis elegans excretory (renal) system, the excretory duct cell and pore cell. Lipocalins are a large family of secreted proteins that transport lipophilic cargos and participate in intercellular signaling. lpr-1 is required at a time of rapid luminal growth, it is expressed by the duct, pore and surrounding cells, and it can function cell non-autonomously. These results reveal a novel signaling mechanism that controls unicellular tube formation, and provide a genetic model system for dissecting lipocalin signaling pathways.     

Divisispiculimermis mirus n. gen., n. sp. (Mermithidae: Nematoda) Parasitizing Midges in Córdoba,Argentina

Divisispiculimermis mirus n. gen., n. sp., a mermithid parasitizing larvae of Chironomus sp. in the Cajón o Grande Stream, Córdoba, Argentina, is described. The new genus differs from all other mermithid genera in having paired spicules which are separated and divided into proximal and distal sectors. The other diagnostic characters of the genus are medium size, nematodes with the cuticle appearing smooth (lacking cross fibers under the light microscope); head separated from the rest of the body by a slight constriction at the level of the amphids, six cephalic papillae, mouth papillae absent, mouth opening posterior to level of cephalic papillae; six hypodermal chords at midbody; weakly S-shaped vagina; postparasitic juvenile with a tail appendage.     

Variation among Populations of Belonolaimus longicaudatus

Three North Carolina populations of Belonolairnus longicaudatus differed significantly from three Georgia populations in stylet measurements, the c ratio, the distance of the excretory pore from the anterior end for both sexes; the a ratio for females only; and the total body length, tail length, and spicule length for males only. The Georgia nematodes were stouter, and the females possessed sclerotized vaginal pieces. The distal portion of the spicules of North Carolina males had an indentation and hump lacking in those of the Georgia males. The haploid number of chromosomes was eight for males from all populations of B. longicaudatus and a North Carolina population of B. maritimus. Interpopulation matings of the Tarboro, N.C. and Tifton, Ga. populations indicated that the offspring produced were infertile. Morphological differences and reproductive isolation suggest that the North Carolina and the Georgia populations belong to different species.     

Description of Meloidoderita polygoni n. sp. (Nematoda: Meloidoderitidae) from USA and Observations on M. kirjanovae from Israel and USSR

Meloidoderita polygoni n. sp. is described and illustrated from roots of smartweed (Polygonum hydropiperoides) from Beltsville, Maryland. This new species is similar to M. kirjanovae but differs especially in having larger spines on the cystoid bodies, females with the anus much closer to the vulva, and more posterior excretory pore. M. polygoni differs from M. safrica particularly in having females with a shorter stylet, a DGO much closer to base of stylet, greater distance between vulva and anus, and larger cystoid bodies. LM and SEM observations showed only three incisures in lateral fields of juveniles and males and no bursa in males. Morphometric data and illustrations are given for M. kirjanovae from mint (Mentha longifolia) in Israel and some details on a limited number of specimens from Armenian SSR. LM examination of juveniles from both these areas indicated only three incisures in lateral fields. Males from Israel had no detectable bursa and appeared to have only three incisures in lateral fields. (Males from Armenian SSR not observed.)     

Margollus bokanicus n. sp. from Iran,the Fourth Species of a Rare Nematode Genus (Dorylaimida,Tylencholaimellidae)

Margollus bokanicus n. sp., collected from natural habitats in Khorasaneh district, Bokan, West Azarbaijan province, Iran, is described. Morphological and morphometric data are provided as well as drawings and light microscopy illustrations. The new species is characterized by a medium size body length (0.60 to 0.73 mm), labial and postlabial sclerotizations, lip region 7-μm wide, offset by constriction and long neck (167 to 207 μm), long pharyngeal basal bulb (27 to 36 μm) or 16% to 17% of total neck length, female genital system monodelphic–opisthodelphic, anterior branch reduced to a uterine sac (26–29 μm) or 1.1 to 1.3 times the body diameter, long posterior uterus (25–28 μm) or 1.1 to 1.3 times the body diameter, V = 40 to 47, cylindroid female tail (17 to 24 μm, c = 31 to 38, c’ = 1.1 to 1.4), and males unknown. This taxon is easily distinguishable from other Margollus species by its smaller general size and more posterior vulva. A compendium of Margollus species is also presented.     

Morphological and Molecular Characterization of Gracilacus wuae n. sp. (Nematoda: Criconematoidea) Associated with Cow Parsnip (Heracleum maximum) in Ontario,Canada

Gracilacus wuae n. sp. from soil associated with cow parsnip in Ontario, Canada is described and illustrated. Morphologically, females have a long stylet ranging from 80 to 93 µm long, the lip region not offset from the body contour, without lateral lips but with large and flat submedian lobes, the mouth opening slit-like elongated laterally and surrounded by lateral flaps, the excretory pore is anterior to the knobs of the stylet; males without stylet and the pharynx degenerated. The fourth-stage juveniles lack a stylet, the pharynx degenerated, and can be differentiated into preadult females and males based on the position of the genital primordia. The third-stage juveniles are similar to females but smaller. Phylogenetic studies using the rDNA small subunit 18S, large subunit 28S D2/D3, and internal transcribed spacer (ITS) sequences collectively provide evidence of a grouping with other Gracilacus and some species of Paratylenchus with stylet length of females longer than 41 µm deposited in GenBank.     

Meloidogyne californiensis n. sp. (Nemata: Meloidogyninae), Parasitic On Bulrush,Scirpus robustus Pursh

Meloidogyne californiensis n. sp. is described and illustrated from bulrush Scirpus robustus in California. LM and SEM studies revealed that this species differs from other known species in the genus Meloidogyne especially by the prominent posterior cuticular protuberances in the female, the distinct shape of the perineal pattern which is marked by one prominent stria in the perineum, indistinct lateral lines, many broken discontinuous striae on both sides of the arch, and the excretory pore being located posterior to stylet base. Second-stage juveniles 448-628 μm long, stylet length 11-13 μm, styler delicate, with small knobs sloping posteriorly, cephalic region with 2 or 3 annuli, and inflated rectum. Males vary greatly in size (712-1,952 μm), stylet length 18-28 μm (mean 22 μm), cephalic region slightly set off the body with two or three annuli, spear heavy with massive rounded knobs, lateral field marked by four areolated incisures as seen by SEM.     

New sense organ in larval hookworms.

A new ciliary sense organ is described which is bilaterally arranged, one in each lateral cord. It is just posterior to the nerve ring and adjacent to the excretory duct. The cilium is closely associated with another structure which is itself connected to the cuticle beneath the lateral alae. A nervous circuit is proposed which links this receptor via the hemizonid to the nerve ring. The receptor and associated structures are in the infective larvae of Necator americanus and Ancylostoma tubaeforme.     

A Rare Human Case of Dirofilaria repens Infection in the Subcutaneous Posterior Thorax with Molecular Identification

The emergence of Dirofilarial infections in Asia including Vietnam is a clinically significant threat to the community. We here report a rare case of subcutaneous Dirofilaria repens infection on the posterior thoracic wall in a young woman presenting a painful, itchy, and palpable nodule. The adult worm was identified by mitochondrial cox1 and nuclear ITS-2 sequence determination. The diagnosis was additionally confirmed by 16S rRNA sequencing of the endosymbiont Wolbachia pipientis commonly co-existing with D. repens. This is a rare case of subcutaneous human infection on the posterior thoracic region caused by D. repens.     

Ultrastructure of the Feeding Apparatus of Rhabdodemania minima Chitwood, 1936 (Enoplida: Rhabdodemaniidae)

The feeding apparatus of the marine nematode Rhabdodemania minima Chitwood, 1936 has been examined with light and transmission electron microscopy. The buccal capsule consists of a posterior region with smooth walls bearing three sets of three minute denticles at its posterior end and three large onchia in its mid region; a middle region with grooved walls; and an anterior region with costae and six odontia. The anterior and middle portions of the buccal capsule are enveloped by the cephalic cuticle, whereas the posterior region, which is set off from the middle region by a buccal seam, is partially enveloped by the anterior end of the esophagus. Two subventral esophageal glands open into the lumen of the esophagus. Secretions of each of three paraesophageal glands are conveyed through a duct in each of the three corresponding corners of the buccal wall to an opening between labia. A pair of wing-like thickenings, termed pterons, embraces the duct of each paraesophageal gland in the posterior and middle regions of the buccal capsule. A model of how the buccal capsule operates is proposed and tested. Morphological and functional aspects of the buccal apparatus and cephalic cuticle are compared with those of other taxa of the Enoplida, and their phylogenetic implications are discussed.     

Pratylenchus australis n. sp. and Eutylenchus fueguensis n. sp. (Nematoda: Tylenchina) from southern Chile

Two new species of nematodes from southern Chile are described and illustrated. Pratylenchus australis n. sp. is distinguished by its heavy cephalic sclerotization, smooth tail terminus, lack of spermatheca, and absence of males. Eutylenchus fueguensis n. sp. differs from other Eutylenchus spp. by the long female stylet (31 [28-32] μm), strongly sclerotized excretory duct opening posterior to nerve ring, and broadly rounded caudal alae of males.     

Morphological and Molecular Evaluation of a Meloidogyne hapla Population Damaging Coffee (Coffea arabica) in Maui,Hawaii

An unusual population of Meloidogyne hapla, earlier thought to be an undescribed species, was found causing large galls, without adventitious roots, and substantial damage to coffee in Maui, Hawaii. Only in Brazil had similar damage to coffee been reported by this species. Unlike M. exigua from South and Central America, this population reproduced well on coffee cv. Mokka and M. incognita-susceptible tomato but poorly on tomato with the Mi resistance gene. Characterization included SEM images, esterase isozymes, and five DNA sequences: i) the D3 segment of the large subunit (LSU-D3 or 28S) rDNA, ii) internal transcribed spacer (ITS-1) rDNA, iii) intergenic spacer (IGS) rDNA, iv) the mitochondrial interval from cytochrome oxidase (CO II) to 16S mtDNA, and v) the nuclear gene Hsp90. Sequences for ITS-1, IGS, and COII were similar to other M. hapla populations, but within species ITS-1 variability was not less than among species. One LSU-D3 haplotype was similar to a previously analyzed population with two minor haplotypes. Hsp90 exhibited some variation between Maryland and Hawaiian populations distinct from other species. Females were narrow with wide vulval slits, large interphasmidial distances, and more posterior excretory pores; 20% of perineal patterns had atypical perivulval lines. Males had a low b ratio (<12 µm). Juveniles had a short distance between stylet and dorsal gland orifice. Juvenile body length was short (<355 µm) and was different between summer and winter populations.     

A New Root-Knot Nematode Parasitizing Sea Rocket from Spanish Mediterranean Coastal Dunes: Meloidogyne dunensis n. sp. (Nematoda: Meloidogynidae)

High infection rates of European sea rocket feeder roots by an unknown root-knot nematode were found in a coastal dune soil at Cullera (Valencia) in central eastern Spain. Morphometry, esterase and malate dehydrogenase electrophoretic phenotypes and phylogenetic trees demonstrated that this nematode species differs clearly from other previously described root-knot nematodes. Studies of host-parasite relationships showed a typical susceptible reaction in naturally infected European sea rocket plants and in artificially inoculated tomato (cv. Roma) and chickpea (cv. UC 27) plants. The species is herein described and illustrated and named as Meloidogyne dunensis n. sp. The new root-knot nematode can be distinguished from other Meloidogyne spp. by: (i) perineal pattern rounded-oval, formed of numerous fine dorsal and ventral cuticle striae and ridges, lateral fields clearly visible; (ii) female excretory pore at the level of stylet knobs, EP/ST ratio 1.6; (iii) second-stage juveniles with hemizonid located 1 to 2 annuli anteriorly to excretory pore and long, narrow, tapering tail; and (iv) males with lateral fields composed of four incisures anteriorly and posteriorly, while six distinct incisures are observed for large part at mid-body. Phylogenetic trees derived from distance and maximum parsimony analyses based on 18S, ITS1–5.8S-ITS2 and D2-D3 of 28S rDNA showed that M. dunensis n. sp. can be differentiated from all described root-knot nematode species, and it is clearly separated from other species with resemblance in morphology, such as M. duytsi, M. maritima, M. mayaguensis and M. minor.