Description of Bakernema dauniense n. sp. (Nematoda: Criconematidae) from Italy

Bakernema dauniense n. sp., a bisexual species from the rhizosphere of Pinus halepensis Mill. in Italy, is described and illustrated. Primary differentiating characteristics of the female are body annules bearing short, membranous projections 1.4-2.2 μm long, an anterior vulval lip slightly overlapping the posterior, and a linearly arcuate vagina. The juvenile differs markedly from adults by having annules with a beaded margin, which lack membranous projections. Generic and specific relationships of B. dauniense n. sp. are discussed. This occurrence is the first for a species of Bakernema in Europe.     

Description of Dolichodorus grandaspicatus n. sp. (Nematoda: Dolichodoridae)

Dolichodorus grandaspicatus n. sp., collected from soil about roots of a red maple (Acer rubrum L.) in a creek bottom near Ludwig. Johnson County, Arkansas, is described. It differs from two closely related species, D. marylandicus and D. heterocephalus, by the longer spike on the female tail, the lenght of the female tail, and the shape of the extrudable portion of the gubernaculum of the males. It further differs from D. marylandicus by having heavily sclerotized accessory pieces of the vuvla and from D. heterocephalus by having a shorter stylet.     

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.     

Description of Hemicycliophora biosphaera n. sp. from Arizona (Nemata: Criconematidae)

Hemicycliophora biosphaera n. sp. (Nemata: Criconematidae) was found in soil from a fallow field plot within the Biosphere 2 Center, Oracle, Arizona. The nematode species is characterized by continuous and irregular breaks in transverse striae in the lateral field, smooth annules, a rounded-truncate lip region with rounded anterior margins, three lip annules, first labial annule elevated and widened laterally, dome-shaped and elevated labial disc, stylet length (76-97 (μm), VA%T value (30-59), 234-273 body annules, and tail with a terminus offset, cylindrical to slightly conoid digit. Hemicycliophora biosphaera n. sp. most closely resembles H. armandae but differs from it in body width (30-39 vs. 38-54 μm), stylet length (76-97 vs. 95-119 μm), greater number of annules between the excretory pore and esophagus base (4-16 vs. 2), length of the tail terminal spike (16-28 vs. 32 μm), lower Rvan value (9-15 vs. 16), and indistinct spetanatheca vs. distinct spermatheca.     

Three New Species of Heteroderoidea (Nematoda) from the Aleutian Islands

Three new species of Heteroderoidea are described from Adak and Amchitka Islands in the Aleutian chain. Second-stage juveniles of Thecavermiculatus crassicrustata, n. sp., differ from those of T. gracililancea Robbins by having longer stylets (40-45 μm vs 19-22 μm). The female of T. crassicrustata has a longer neck, a more posterior excretory pore, and lacks a posterior protuberance. Meloidodera eurytyla, n. sp., differs from other Meloidodera spp. in that second-stage juveniles have longer stylets (32-35 μm) and much more massive stylet knobs, while males have a longitudinally striated basal head annule. Meloidogyne subarctica, n. sp., can be separated from other Meloidogyne spp. by combinations of the following characteristics: perineal pattern with large oval areas in the tail region devoid of striae, arch with few unbroken striae; female excretory pore 1.5-2.5 × the stylet length from the anterior end; haploid chromosome number = 18; the spermatheca filled with sperm; stylet length of second-stage juveniles 13.5-15.4 μm.     

Taxonomic and Molecular Identification of Bakernema,Criconema, Hemicriconemoides,Ogma and Xenocriconemella Species (Nematoda: Criconematidae)

Populations of Bakernema inaequale, C. petasum, C. sphagni, C. mutabile, Ogma octangulare, Xenocriconemella macrodora and Hemicriconemoides chitwoodi were identified and re-described from different geographical areas in the continental United States and molecularly characterized. Two new species of spine nematodes Criconema arkaense n. sp. from Washington County and Lee County, Arkansas and Criconema warrenense n. sp from Warren, Bradley County, Arkansas are also described and named. Criconema arkaense is characterize by having a conspicuous lip region offset from the body with two annuli, short rounded tail with a thin cuticular sheath and subterminal anus. Criconema warrenense n. sp. has two lip region annuli about the same width, first annulus directed posteriorly, separated by a narrow neck annulus and a short conoid tail, unilobed non-folded annulus. The molecular characterization of Criconema arkaense and Criconema warrenense using ITS1 rDNA gene sequence and the molecular phylogenetic relationships of these new species along with the known spines nematodes are provided.     

Population Dynamics and Description of Ptycholaimellus hibernus n. sp. (Nematoda: Chromadoridae)

Ptycholaimellus hibernus n. sp. from the muddy subtidal of North Inlet Estuary, Georgetown, South Carolina, is described and a key to the genus is provided. P. hibernus differs from all other species of Ptycholaimellus by the shape of the gubernaculum. Ptycholaimellus sp. 2 Hopper 1969 is synonymized with P. ponticus. The abundance of P. hibernus, measured over a 3-year period, is greatest from January to March, coinciding with minimal annual water temperatures (10-15 C). P. hibernus abundance was significantly (negatively) correlated with water temperature and (positively) with the depth of the anoxic sediment layer.     

Mesocriconema ornicauda n. sp. and Ogma floridense n. sp. (Nematoda: Criconematidae) from Two Florida Habitats

Mesocriconema ornicauda n. sp. and Ogma floridense n. sp. are described from two native habitats of central and northwestern Florida. Mesocriconema ornicauda is closest to M. annulatiforme (De Grisse &Loof, 1967) Loof &De Grisse, 1989, but differs by the shorter stylet of the female (43-50 vs. 54-65 μm) and the moderately conoid tail of the male, which is pointed in M. annulatiforme. Ogma floridense is closest to O. hungaricum (Andrassy, 1972) Siddiqi, 1986. Females differ from those of O. hungaricum by the first of two labial annuli being wider, whereas they are subequal in O. hungaricum. Ogma floridense females differ also by entire or bifid cuticular scales, which are consistently divided into two or four projections in O. hungaricum, the shorter body (360-471 vs. 480-550 μm), the shorter stylet (87-98 vs. 95-100 μm), and the more anteriorly located excretory pore (Rex = 17-19 vs. 21-23).     

Xiphidorus amazonensis n. sp. (Nematoda: Longidoridae) from the Brazilian Amazon Basin

Xiphidorus amazonensis n. sp. was found in the rhizospheres of Jatropha curcas, Musa sp., Anona muricata, Cassia tora, Panicum laxum, Paspalum fasciculatum, Aeschynomene sensitiva, Saccharum officinarum, Manihot esculenta, Abelmoschus esculentus, Tamarindus indica, Mangifera indica, Vigna unguiculata, Zea mays, Commelina sp., Cyperus rotundus, Fimbristylis miliacea, Citrus sinensis, and Eichhornia crassipes on the Amazon River island of Xiborena, approximately 40 km southeast of Manaus, capital of the State of Amazonas. The type habitat is flooded annually for about 6 months by the Amazon River. Xiphidorus amazonensis n. sp. differs from the closely related species Xiphidorus yepesara Monteiro, 1976 by the larger size, by a, b, and c values, and by the rounded tail terminus. It also resembles Xiphidorus tucumanensis Chaves and Coomans, 1984, but can be distinguished by its larger size, larger a, b, and c values, more conical female tail, bilobed amphidial pouch, and the presence of a spermatheca full of sperm.     

Mesocriconema kirjanovae (Nematoda: Criconematidae) from Southeastern Spain

An abundant female population of a criconematid species identified as Mesocriconema kirjanovae (Andr ssy, 1962) Loof &De Grisse, 1989 is reported from a natural habitat in southeastern Spain. Measurements and morpho-anatomy obtained with light microscopy and scanning electron microscopy are included and compared with previous data on this species.     

Gastromermis kolleonis n. sp. (Nematoda: Mermithidae), a Parasite of Midges (Chironomus sp. Chironomidae) from Argentina

Gastromermis kolleonis n. sp. (Nematoda: Mermithidae) is described from the Arroyo Saldan River in Córdoba, Argentina. This species parasitizes midges of the genus Chironomus (Chironomidae: Diptera). It is distinguished from other members of the genus by the presence of six longitudinal chords, vulval flaps, degree of ventral displacement of the mouth, and size and shape of the spicule and amphids.     

Further Details and SEM Observations on Meloidogyne marylandi (Nematoda: Meloidogynidae)

Specimens of Meloidogyne marylandi from Bermuda grass and a population from Zoysia grass were examined and compared morphologically by light and electron microscopy. The populations probably are conspecific and the differences noted in the Zoysia population, mainly those of second-stage juveniles (J2) with shorter tails, are considered normal variations rather than representing another form. Scanning electron microscope observations provided additional details of the perineal pattern and head of females and head and lateral fields of second-stage juveniles. Relationship of M. marylandi to closely related species is given. This species is currently known to occur only in Maryland, and populations previously reported from this state as M. graminis are now considered to be M. marylandi. Other reports of M. graminis in the United States now need to be reconfirmed by examination of voucher or recollected specimens.     

Description of Distolabrellus veechi n. gen., n. sp. (Nematoda:Rhabditidae)

A new, monotypic genus and species in the subfamily Mesorhabditinae is described and illustrated. The primary character which separates the species and genus from all others in the Rhabditidae is a lip region with six set-off and well-separated liplets of two alternating shapes. Other diagnostic characters are transverse and fine longitudinal body striations, cuticular micropores, a prismatic prostom, well-developed esophageal collar, and three denticles on each metarhabdion. Males have a peloderan, open bursa bearing two pre- and seven post-anal bursal papillae, fused spicules over 50 μm long, and paired diverticulate cement glands associated with the vas deferens.     

Hexamermis cathetospiculae n. sp. (Mermithidae: Nematoda), a Parasite of the Rice Stemborer,Tryporyza incertulas (Wlk.) (Pyralidae: Lepidoptera) in Malaysia

Hexamermis cathetospiculae n. sp. (Mermithidae: Nematoda), a parasite of the rice stemborer, Tryporyza incertulas (Wlk.), is described. This mermithid was observed to control the stemborer in Malaysia. It is distinguished from other members of the genus by the shape of the vagina, the nearly straight spicules, and the form of the amphids.     

Redescription of Heterodera fici (Nematoda: Heteroderidae) with SEM Observations

Heterodera fici is redescribed and illustrated with comparative details and revised measurements and diagnostic characters of the females, males, cysts, and juveniles from Maryland and Pakistan. This species is in the "schachtii group" (cysts lemon shaped, with bullae, and ambifenestrate) but the fenestrae in some cysts, presumab!y young ones, are small and widely spaced, appearing bifenestrate. It is most closely related to H. schachtii, H. glycines, and H. cajani but differs from these species especially in having cysts with small, scattered bullae and weakly developed underbridge; and males with four small nipples on tail tip. Scanning electron microscopy (SEM) observations of the specimens are also presented. The relationship of this species to closely related forms is discussed.     

Macroposthonia sicula n. sp. (Nematoda: Criconematidae), a Parasite of Olive Trees in Sicily

Macroposthonia sicula n.sp. collected from rhizosphere and roots of olive (Olea europaea L.) at Kamarina, Sicily, Italy, is described and illustrated. It is distinguished from the related species (M. sphaerocephala and M. maskaka) by the longer styler and the characteristic narrowing postvulval portion of the body.     

Four New Species of the Genus Hemicriconemoides (Nematoda:Criconematidae)

Four new species of the genus Hemicriconemoides (H. californianus n.sp., H. taiwanensis n.sp., H. annulatus n. sp., and H. nitida n.sp.) are described. The range of total length of H. mangiferae is increased on the basis of specimens collected in Israel, Observations on H. mangiferae and H. litchi support the validity of H. litchi as distinct from H. mangiferae.     

Scanning Electron Micrographs of the Anterior Region of Some Species of Tylenchoidea (Tylenchida: Nematoda)

Micrographs of the anterior region of 42 species in 36 genera of Tylenchoidea obtained with a scanning electron microscope are presented. Greater detail, depth of focus, and structures not previously seen with the light microscope have been obtained in this study. Some of the implications of the morphology of the face view on the classification of the rlylenchoidca are discussed.