Rotylenchus ouensensis n.sp. (Nematoda: Hoplolaimidae) from the British Isles

Summary Females and males of a new species of Rotylenchus are described from a coniferous woodland at St. Ouens, Jersey. This species is characterized by having virtually no overlap of the oesophagus over the intestine, 7 to 10 head annules, the anterior body cuticle tessellated and the lateral field irregularly areolated along its entire length, more densely so around the phasmid on the female tail. A key to the species of Rotylenchus is given. ac]19810407     

Discocriconemella inaratus n. sp. and Criconemoides inusitatus n. sp. (Nematoda) from Iowa

Discocriconemella inaratus n. sp. from Iowa prairies is characterized by a single offset disk-shaped head annule which is often discontinuous, a sigmoid vagina, a stylet length of 51-61 μm, and 77-100 smooth body annules. Criconemoides inusitatus n. sp. from Iowa woodlands is characterized by two offset head annules, a "closed" vulva, a straight vagina, no overlapping anterior vulva lip, a stylet length of 42-50 μm, and 71-86 smooth body annules.     

Description of Pararotylenchus belli n.sp. (Nematoda:Hoplolaimidae)

A new species of Pararotylenchus Baldwin &Bell, 1981 from the Pacific coastal area of California is described. Numerous females and juveniles were recovered, but no males were found. Pararotylenchus belli n.sp. is most similar to P. sphaerocephalus, but females of P. belli are shorter and have a shorter stylet and a hemispherical tail. Specimens from a cereal field in South Dakota were identified as P. colocaudatus.     

Heterodera canadensis n. sp. (Nematoda: Heteroderidae) from Spike-Rush (Eleocharis acicularis (L.) R. &S.) in Quebec,Canada

Heterodera canadensis n. sp. is described and illustrated from the roots of spike-rush, Eleocharis acicularis (L.) R. &S., in Deschenes, Quebec. This new abullate species is related to Heterodera graminophila Golden and Birchfield, 1972, but differs significantly in cyst shape, cone top structures, body length of the second-stage larva (520-600 μm, vs. 380-400 for H. graminophila) and tail length (110-120 μm, vs. 57-67 for H. graminophila). A taxonomic key based on cyst and second-stage larva characters is provided for identification of the fifteen species in the Heterodera goettingiana group.     

Brachydorus swarupi sp. n. (Nematoda: Dolichodorinae) from Soil about Roots of Arecanut Palm in Kerala State,India

Brachydorus swarupi sp. n. is described from soil about roots of arecanut palm in Kerala State, India. It is the second species to be described in Brachydorus De Guiran and Germani 1968 and differs from B. tenuis, the type species, by its greater length (1.52-2.34 mm for B. swarupi vs. 1.03-1.32 mm for B. tenuis); longer and more delicate stylet (26-35 μm for B. swarupi vs. 20-23 μm for B. tenuis); head shape with concave protrusion at oral aperture (simple rounded in B. tenuis); shorter isthmus and larger posterior bulb in B. swarupi; shorter tail (in B. tenuis c = 9.7 [8.6-11.5] in female, c = 42.3 [33-48] in male); larger spicules and gubernaculum (22-39 μm and 9 -1 2 μm, respectively, for B. tenuis); and phasmids near posterior connection of caudalalae and tail (almost central on caudalalae of B. tenuis). The relationship of Brachydorus to Dolichodorus is discussed.     

Host Range Assessment of Helicotylenchus pseudorobustus (Tylenchida: Hoplolaimidae) on Pasture Species

The host status of 15 commonly occurring pasture species for Helicotylenchus pseudorobustus was tested in a greenhouse trial. Only tall fescue, with and without Neotyphodium endophyte infection, was a good host (Pf/Pi = final/initial population > 1). Inoculation survival was tested in a second trial, which showed that only 10% of the H. pseudorobustus nematodes survived the first 7 days after inoculation. When the Pf/Pi was adjusted to account for a 10% survival, all of the grass and clover hosts tested had a Pf/Pi > 1. Both trials showed a positive correlation between increased numbers of H. pseudorobustus and free-living nematodes.     

Description of Pratylenchus gutierrezi n. sp. (Nematoda: Pratylenchidae) from Coffee in Costa Rica

A lesion nematode, Pratylenchus gutierrezi n. sp., collected from the roots of coffee in the Central Plateau of Costa Rica, is described and illustrated. Its relationships to Pratylenchus flakkensis, P. similis, and P. gibbicaudatus, the only other species of the genus having two head annules, males, or spermatheca with sperm, and an annulated tail terminus, is discussed. Other distinctive characters are its posterior vulva (mean of 80%); its prominently rounded stylet knobs, low head, and subcylindrical tail. SEM observations provide additional details of females and males, especially face views, which show for the first time sexual dimorphism.     

Criconemella anastomoides n. sp. (Nematoda: Criconematina) from Pakistan

Criconemella anastomoides, described and illustrated herein, is characterized by the presence of regular anastomosis on the body, two zig zag lateral lines, stylet knobs sloping posteriorly, short stylet, and short body length.     

Sauertylenchus labiodiscus n. gen., n. sp., from Australia (Nematoda:Tylenchorhynchinae)

Sauertylenchus labiodiscus n. gem, n. sp. is described and illustrated from soil around Rhagodia sp. in Australia. It can be distinguished from the most closely related genus Tylenchorhynchus Cobb, 1913 by the distinctly set-off, rounded, lip region with a conspicuous labial disc, and long thin stylet. The face view and spicules of Sauertylenchus labiodiscus are illustrated with scanning electron micrographs. The subfamilies Tylenchorhynchinae and Merlininae ale discussed.     

Helicotylenchus scoticus n.sp. and a conspectus of the genus Helicotylenchus Steiner, 1945 (Tylenchida: Nematoda)

Summary Helicotylenchus scoticus n. sp. is described. It was found at an altitude of 660 m on the north-west slope of Sgurr Cos na Breachd-laoidh, Scotland, in a rough grassland consisting predominantly of tufted hair grass (Deschampsia caespitosa). This species is characterized by a relatively long spear and an oesophagus which superficially appears to abut on to the intestine with virtually no overlap. The number of nominal species in the genus Helicotylenchus has increased considerably over recent years and stands now at 154 species. The task of identifying species in this genus using dichotomous keys has become increasingly more difficult. As a practical alternative a compendium is given which uses nine of the most diagnostic characters.     

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.     

Criconematina (Nematoda: Tylenchida) from the Aleutian Islands

A new genus (Cerchnotocriconenta) and three new species (C. psephinum, Hemicycliophora amchitkaensis, and Paratylenchns amundseni) are described from Adak and Amchitka Islands in the Aleutian chain. The new genus differs from all other criconematid genera in having irregular, convex sculpturing consisting of small, oval plates on the anterior and posterior regions of each annule, with the mid-annular region minutely punctate or dentate. H. arnchitkaensis n. sp. resembles H. similis Thorne and H. zuckermani Brzeski, but has only one head annule, instead of two. P. antundseni n. sp., which has a stylet 17-19 μm long, is similar to P. tateae Wu &Townshend and P. labiosus Anderson &Kimpinski, but differs by the presence of males and the possession of conoid-truncate lip region, functional spermatheca, and long male tail (c = 8.5-9.5). Seriespinula seymouri Wu (Mehta &Raski), Nothocrieonema longulum (Gunhold) De Grisse &Loof, and Macroposthonia xenoplax (Raski) De Grisse &Loof are also reported from the islands.     

Hoplolaimoidea (Nematoda: Tylenchida) from the Aleutian Islands with Descriptions of Four New Species

Four new species of hoplolaimoid nematodes (Merlinius adakensis, Pratylenchoides megalobatus, Pratylenchus pratensisobrinus, and Pratylenchus ventroprojectus) are described from Adak Island in the Aleutian chain. M. adakensis n. sp. is separated from other species by body length (0.96-1.3 mm), stylet length (32-36 μm), number of tail annules (49-68), and c'' (3.1-4.1). P. megalobatus n. sp. differs from all known Pratylenchoides spp. by having a very long esophageal gland lobe (b'' = 2.4-3.3, overlap 3-6 times the body width). P. pratensisobrinus n. sp. closely resembles P. pratensis (de Man) Filipjev, but has a longer stylet (15-17 μm), a longer tail (c = 12-15; c'' = 2.8-3.7), and more tail annules (23-37). P. ventroprojectus n. sp. is distinguished by body length (392-475 μm), three lip annules, low and flattened cephalic capsule, and presence of terminal subventral projection. Pratylenchoides variabilis Sher, Helicotylenchus amplius Anderson &Eveleigh, and H. spitsbergensis Loof are also reported from Adak and Amchitka Islands.     

Torquatoides trogoni n. sp. and Excisa ramphastina n. sp. (Nematoda: Habronematoidea: Habronematidae) in birds from the area de Conservacion Guanacaste, Costa Rica

Two new species of habronematid nematodes are described in birds from the Area de Conservacion Guanacaste, Costa Rica. Torquatoides trogoni n. sp., in Trogon massena, can be distinguished from T. torquata, T. bengalensis, and T. crotophaga in lacking lateral alae. Among species lacking lateral alae, the new species differs from T. balanocephala in having 14 versus 8-10 cephalic cuticular plaques, 21-22 versus 13-17 pairs of preanal papillae, and a beak-shaped versus U-shaped gubernaculum. The new species differs from T. singhi in body length, in having 21-22 versus 10 pairs of precloacal papillae, longer spicules, and larger eggs. The new species differs from T. crotophaga, the only other species known from Central America, in lacking lateral alae, and having 14 versus 6 cephalic cuticular plaques, 21-22 versus 17 pairs of precloacal and 3 versus 2 pairs of postcloacal papillae, and a gubernaculum. Excisa ramphastina n. sp., in Ramphastos sulfuratus, can be distinguished from E. excisa, E. biloba, E. buckleyi, E. dentifera, and E. khalili in having 1 lateral ala versus none, cervical papillae anterior versus posterior to the nerve ring, and asymmetrical caudal alae. Excisa ramphastina is similar to E. curvata in having cervical papillae anterior to the nerve ring but differs in having 1 lateral ala versus none, asymmetrical caudal alae, an average spicule ratio of 1:4.4 versus 1:3.3, and 4 versus 2 pairs of sessile papillae. The new species differs from E. columbi in having 1 versus 2 lateral alae, in the length of the spicules, in having a different spicule ratio, and in the numbers of sessile papillae.     

Protrellus dixoni n. sp. (Nematoda: Thelastomatidae) from the cockroach Drymaplaneta variegata

Abstract

In New Zealand, Protrellus dixoni n. sp. occurs in the hind gut of the introduced Australian cockroach Drymaplaneta variegata. It is distinguished from all other Protrellus species by its morphology. Females have a well developed muscular ovijector with a sphincter, and a conical tail with a filiform projection; males have four, not three, tail papillae. The taxonomic history of the genus is discussed and the generic diagnosis emended. New combinations include Protrellus eurycotesi, P. ischnopterae, P. ituana, and P. gurri. The population structure of P. dixoni in adult hosts is described: there are never more than one adult male, and usually few (one to three) adult females per host.     

Steinernema biddulphi n. sp., a New Entomopathogenic Nematode (Nematoda: Steinernematidae) from South Africa

A new species of entomopathogenic nematode (EPN), Steinernema biddulphi n. sp., was isolated from a maize field in Senekal, Free State Province of South Africa. Morphological and molecular studies indicated the distinctness of S. biddulphi n. sp. from other Steinernema species. Steinernema biddulphi n. sp. is characterized IJs with average body length of 663 μm (606–778 μm), lateral fields with six ridges in mid-body region forming the formula 2,6,2. Excretory pore located anterior to mid-pharynx (D% = 46). Hyaline layer occupies approximately half of tail length. Male spicules slightly to moderately curved, with a sharp tip and golden brown in color. The first generation of males lacking a mucron on the tail tip while the second generation males with a short filamentous mucron. Genital papillae with 11 pairs and one unpaired preanal papilla. The new species is further characterized by sequences of the internal transcribed spacer (ITS) and partial 28S regions (D2-D3) of the ribosomal DNA (rDNA). Phylogenetic data show that S. biddulphi n. sp. belongs to the “bicornutum” clade within the Steinernematidae family.     

Description of Pratylenchoides sheri n. sp. (Nematoda: Pratylenchidae)

Pratylenchoides sheri n. sp., a bisexual species from the Pacific coastal area of California, is described and illustrated. Its most distinctive characters are the esophageal glands slightly overlapping the intestine dorsally, the large ventrally slanting esophago-intestinal valve, the lack of labial sectors in the first lip annule, the presence of males, and apparently functional spermatheca. Pratylenchoides sheri is morphologically similar to P. magnicauda, but differs in length and labial conformation, its more anterior vulva, and the presence of males. Relationships of head and esophagus gland lobe characters of P. sheri are compared to other Pratylenchoides species.     

Tylenchocriconema alleni n. g., n. sp. from Guatemala (Tylenchocriconematidae n. fam.; Tylenchocriconematidae n. superfam.; Nematoda)

Tylenchocriconema alleni n.g.n.sp, is described from soil about roots of a bromeliad from Guatemala City, Guatemala. It has characteristics of both the Tylenchoidea and Criconematoidea. Tylenchocriconematidae, n. fam., and Tylenchocriconematoidea, n. superfam., are proposed to express the relationship of this species to other taxa. Tylenchulidae and Paratylenchidae are considered closely related, and Tylenchulidoidea, n. rank, is proposed to indicate their relationship.