Two New Species of Actinolaimidae Thorne, 1939 (Nemata: Dorylaimida) from China

Two new species of Actinolaimidae are described from China. Trachactinolaimus brevicaudatus n. sp. is 3.4-4.4 mm long; a = 40-60, b = 3.5-5.2, c = 20-21 in female and 34-39 in male; odontostyle length is 29-33 µm; spicules are 67-77 µm long; and the stoma has four onchia with numerous mural denticles. The female has a longitudinal vulva, and the male has 20 to 23 contiguous ventromedian supplements. Egtitus sinensis n. sp. is 1.7-2.2 mm long; a = 24-33, b = 3.1-3.9, c = 16-19 in female and 0.7-0.9 in male; odontostyle length is 25-29 µm; spicules are 55-56 µm long; and the prerectum 53-77 µm long. The cardia is short and blunt conoid, 13-19 µm long. The male has 12 to 13 ventromedian supplements at intervals of 2-3 µm.     

Two New Species of Aphelenchoididae (Nemata) from Declining Red Pines in Maryland

Aphelenchoides resinosi n. sp. and Ektaphelenchus joyceae n. sp. are described and illustrated from red pines of the Allegheny plateau of Maryland, USA. The new species were found in trees infested with Bursaphelenchus xylophilus. Primary diagnostic characters of A. resinosi females are constriction of the head, basal stylet knobs, tong postuterine sac, two incisures in the lateral field, and conical tail four to five anal body widths long with a simple terminal mucro. Diagnostic characters of the males are two pairs of subventral caudal papillae and spicule shape: Primary diagnostic characters of E. joyceae females are a slight constriction of the head, six similar lips, conical tail, and short postuterine sac. Diagnostic characters of the males are spicule size and shape, a single row of spermatocytes, and one pair of caudal papillae. Within-tree distributions of A. resinosi and E. joyceae are presented. A total of 70% of both red-needled and chlorotic-needled trees in the study were positive for A. resinosi and E. joyceae. Branch hierarchy was related to the percentage of samples positive for A. resinosi.     

Two New Species of Prismatolaimus de Man, 1880 (Nemata: Prismatolaimidae) in Southern Chile

Two new species of Prismatolaimus are described from Orange Bay, Hoste Island, Chile. Prismatolaimus novoporus sp. n. is distinguished by its females being 1.08-1.28 mm long and monovarial with a long postvulvar sac, and having a long tail (c'' = 21.5-32.2); males have 11-20 supplements confined to the posterior part of the body. Prismatolaimus chilensis sp. n. is distinguished by its amphidelphic reproductive system, short tail (c'' = 9.5), V = 63.4; males have 23 supplements reaching up to the neck region. A well-developed dorsal body pore behind the cardia connected with an apparently glandular organ is reported in P. novoporus sp. n. Function of the organ is unknown, and it is not a general feature in the genus. The generic diagnosis of Prismatolaimus is emended and keys to species, both females and males, are presented. The systematic position of Prismatolaimus is discussed, and it is judged to be the only genus of Prismatolaimidae. Also, it is concluded that Prismatolaimidae and Bastianidae represent two sister taxa in Araeolaimida or Leptolaimina.     

Descriptions of Three New Longidorus Species from Slovakia (Nemata: Longidoridae)

Three new Longidorus species from Slovakia are described. Longidorus carpathicus n. sp. most closely resembles Longidorus silvae but differs by having a longer odontostyle, odontophore, and total stylet; smaller a and c ratios; and longer distance to the guide ring. This new species also resembles L. picenus, L. macrosoma, and L. major but differs by having a narrower lip width. It further differs from L. picenus by having a longer odontostyle and smaller c ratio, and by lacking males; from L. macrosoma by having a longer odontostyle, smaller c ratio, by lacking males, and a more pronounced J1 tail peg; and from L. major by having a shorter body length, longer odontostyle, longer odontophore, and longer J1 tail peg. Longidorus piceicola n. sp. most closely resembles L. eridanicus, from which it differs by having a greater lip width, longer tail, smaller c ratio, larger c'' ratio, shorter hyaline tail length, and a conically rounded vs. hemispherical tail. This new species differs from L. cylindricaudatus by having a larger lip width, longer odontostyle and odontophore, and a greater distance to the guide ring; from L. nevesi by having a shorter body length, longer odontostyle, larger c'' ratio, and shorter hyaline tail length. Longidorus juglansicola n. sp. most closely resembles L. athesinus but differs by its longer body, wider lips, and larger a and c ratios. It closely resembles L. vineacola but differs by its shorter body length, smaller c ratio, and an almost parallel lip outline vs. an expanded lip outline; from L. lusitanicus by a longer odontophore and tail, and an almost parallel lip outline vs. an expanded lip outline.     

Trichodorus elefjohnsoni n. sp. (Nemata: Trichodoridae) from Undisturbed Appalachian Forest

A new species of Trichodoridae, Trichodorus elefjohnsoni, is described from undisturbed regions of Great Smoky Mountains National Park, United States. It resembles T. orientalis De Waele &Hashim, 1984, T. persicus De Waele &Sturhan, 1987, and T. taylori De Waele, Mancini, Roca, '' Lamberti, 1982 in arrangement of ventromedian cervical papillae and posterior preanal supplements, but differs by combinations of the following characteristics: body length 516-731 μm; spicule length 33-50 μm, spicules densely striated, constricted medially; vaginal sclerotizations ovate; one pair of lateral body pores near vulva.     

Identification of Entomopathogenic Nematodes in the Steinernematidae and Heterorhabditidae (Nemata: Rhabditida)

This paper contains taxonomic keys for the identification of species of the genera Steinernema and Heterorhabditis. Morphometrics of certain life stages are presented in data tables so that the morphometrics of species identified using the keys can be checked in the tables. Additionally, SEM photographs and diagnoses of the families and genera of Steinernematidae and Heterorhabditidae are presented.     

A New Species and New Combinations of Brevitobrilus Tsalolikhin, 1981 (Nematoda: Tobrilidae) from Spain

A new species of Brevitobrilus Tsalolikhin, Brevitobrilus montanus n. sp., found in high mountain lakes and rivers in Granada, Spain, is described. Additional data on Brevitobrilus granatensis (Ocafia &Zullini, 1988) n. comb. are provided. Brevitobrilus raontanus n. sp. is characterized by moderate size (1.3-1.8 mm), amphid aperture width one-quarter the head width, subterminal seta distance from terminus four times the width of the terminal end of the tail, and supplements S5 and S6 separated. Tobrilus granatensis Ocafia &Zullini, 1988; Tobrilus sardus Vinciguerra &Zullini, 1991; and Tobrilus siculus Vinciguerra &Zullini, 1991 are all transferred to Brevitobrilus. Differences among the 13 species of Brevitobrilus are discussed.     

Morphometrics of Infective Juveniles of Steinernema spp. and Heterorhabditis bacteriophora (Nemata: Rhabditida)

Selected morphometrics of Heterorhabditis bacteriophora and seven species of Steinernema from in vivo culture were compared in relation to time of harvest. In addition, five Steinernema species were reared in vitro and their morphometrics were compared with those from in vivo culture. With in vivo culture, there was generally a negative linear relationship between body length of infective juveniles (IJ) and time of harvest. The distance from the anterior end to the excretory pore (EP) and the tail length (T) of IJ also varied with time of harvest. The E percentage (= EP/T x 100) was the least variable. Body lengths of IJ reared in vitro were much less than those of IJ reared in vivo. The study suggests that IJ harvested from in vivo culture within 1 week of emergence from cadavers are best for species identification. Infective juveniles from in vitro culture should not be used for species identification.     

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.     

Marine Nematodes of Bothnian Bay,Finland: Ethmolaimus hailuotoensis n. sp. (Ethmolaimidae: Nemata)

Ethmolaimus hailuotoensis n. sp. from Bothnian Bay, northern Baltic Sea, is described and illustrated. Ethmolaimus hailuotoensis n. sp. has a strongly sclerotized luminal lining of the terminal esophageal bulb and esophagus. The most characteristic feature is a lateral series of large concentric, sclerotized rings with a fine, internal longitudinal oval sclerotization. In addition, E. hailuotoensis n. sp. is distinguished from other Ethmolaimus species by its smaller body size, fewer number of precloacal supplements (7-8), conical tail, and the position of amphid posterior to the buccal cavity. Females of E. hailuotoensis n. sp. studied were hermaphroditic. Ethmolaimus hailuotoensis n. sp. coexisted with E. pratensis. Ethmolaimus pratensis from Bothnian Bay has a characteristic row of sublateral hypodermal glands, a character not before seen in Ethmolaimidae.     

Pratylenchoides hispaniensis n. sp. (Nemata: Pratylenchidae)

Pratylenchoides hispaniensis n. sp. is described and illustrated from a bisexual population found in a natural habitat at Santa Elena, Jaen, central Spain. Its main distinctive characters are very long esophageal gland lobe (81-117 μm; N'' = 51-71) overlapping the intestine 3 to 5 times the body width; lateral field with six incisures; stylet knobs sloping posteriorly; labial disc encircled by the irregular sectors of the first annule; tail cylindrical, extremity annulated, and frequently with a slight dorsal indentation of the hyaline portion at the end of the lateral field. Pratylcnchoides hispaniensis n. sp. appears closely related to P. megalobatus and P. nevadensis. It differs from the former primarily by its longer body length (761-998 vs. 430-621 μm), longer stylet length (20.5-24.4 vs. 18-21 μm), six incisures in the lateral field vs. four for P. megalobatus, and posteriorly sloping stylet knobs vs. rounded or anteriorly flattened knobs in P. megalobatus. It differs from P. nevadensis mainly by the shape of the stylet knobs (sloping in P. hispaniensis vs. rounded in P. nevadensis), length of esophageal lobe (81-117 vs. 34-82 μm), and position of esophageal gland nuclei (all posterior to esophago-intestinal junction in P. hispaniensis vs. at least one nucleus anterior to junction in P. nevadensis).     

Thalassomermis megamphis n. gen., n. sp. (Mermithidae: Nemata) from the Bathyal South Atlantic Ocean

Thalassomermis megamphis n. gen., n. sp. (Mermithidae: Nemata) was extracted from sediment collected off the coast of Brazil at a depth of approximately 1,000 m. Although the food of this new nematode is unknown, the reduction of the stoma and esophagus and presence of a trophosome indicate that it is parasitic in its juvenile stages. Thalassomermis megaraphis n. gen., n. sp. is assigned to Mermithidae because of its similarity to that family in the appearance of the cephalic sensory receptors, the long and tubular vagina, and copulatory muscles of the male extending posteriorly throughout most of the length of the tail. Thalassomermis megamphis n. gen., n. sp. differs from all other members of Mermithidae by the large, lenticular, intracuticular amphidial fovea with coiled, emergent terminal filaments as well as the small amphidial aperture situated over the center of the fovea.     

Three New Species of Nothacrobeles (Nemata: Cephalobidae) from the Mojave Desert, California

Three new species of Nothacrobeles are described from localities in the Mojave Desert, southern California. Nothacrobeles triniglarus n. sp. is characterized by the presence of a long post-vulval sac and three tubular adoral projections. Both N. spatulatus n. sp. and N. nanocorpus n. sp. are smaller than any other known species within the genus. Nothacrobeles spatulatus n. sp. has labial probolae that are short and spatulate without a basal ridge, whereas those of N. nanocorpus n. sp. are flattened and plate-like. Furthermore, N. nanocorpus n. sp. is unique by its extremely short esophageal corpus (less than 25 µm long in adult females) and the small size of its guard processes. An emended diagnosis of the genus is given to accommodate distinctive characteristics of these new species. A table comparing the 11 valid species of Nothacrobeles is presented.     

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.     

Descriptions of Three New Longidorus Species from Alaska (Nematoda: Longidoridae)

Three new Longidorus species, L. alaskaensis n. sp., L. paralaskaensis n. sp., and L. bernardi n. sp., are described from specimens collected near Fairbanks, Alaska. Longidorus alaskaensis differs from all species of Longidorus by the presence of a caecum-like structure situated at the reflex of the oviduct. Longidorus paralaskaensis most closely resembles L. alaskaensis n. sp., L. crassus Thorne, L. picenus Roca, Lamberti &Agostinelli, and L. silvae Roca, differing from the last three of these species by having a parallel vs. a tapered lip region, and from all four by having a more narrowly rounded tail tip. Longidorus paralaskaensis differs from L. alaskaensis by having a longer odontostyle (119-128 vs. 110-118 μm) and by lacking the caecum-like structure found at the reflex of the oviduct. Longidorus bernardi n. sp. most closely resembles L. mirus Khan, Chawla &Seshadri, from which it differs by having a longer tail with a more acutely rounded tip, a longer body length (3.5-4.6 vs. 3.0-3.6 μm), and a larger c'' value (1.6-1.8 vs. 1.3-1.6). Longidorus bernardi differs from L. sylphus Thorne, L. africanus Merny, L. auratus Jacobs &Heyns, and L. conicaudatus Khan by having a slightly expanded lip region vs. a lip region with parallel body walls and a more finely rounded tail tip.     

Descriptions of Four New Species of Criconematoidea (Tylenchina: Nemata) from Southern Chile

Four new species of Criconematoidea are described from Hoste Island, Chile. Criconema certesi n. sp. is distinguished by the fine, spine-like, cuticular extensions on body annuli; projection of annuli into rows of scales on posterior part of body; single, smooth, labial annulus set off by short collar from second (first body) annulus which is about same diameter as first (labial) annulus. Male with prominent caudal alae, slender curved spicules, and four incisures in lateral field. Ogma terrestris n. sp. is distinguished by small scales with rounded tips bearing minute, short bristles; scales number 21 at mid-body; and first (labial) annulus rounded, not retrorse, not set off from succeeding annuli, narrower in diameter from second (first body) annulus. Hemicycliophora macrodorata n. sp. is distinguished by its large size (L = 1.52 [1.28-1.72] mm); large stylet (146 [127-161] μm); annuli = 297 (280-315); tail slightly spicate, lateral field with or without interruptions of incisures, occasional anastomoses; and males with U-shaped spicules. Paratylenchus fueguensis n. sp. is distinguished by its prominent stylet with large, rounded knobs (4-5 μm across); cephalic region rounded not at all set off; lateral field with four incisures; lateral vulvar membranes present; and male tail short, strongly curved (almost 180°) ventrad.     

Hemicycliophora hellenica n. sp. (Nemata: Criconematidae) from Greece

Hemicycliophora hellenica n. sp. is described and illustrated from a bisexual population found in Filippias, Epirus, Greece, in the rhizosphere of giant reed (Arundo donax) and unidentified aquatic plants along the edge of irrigation canals. Hemicycliophora hellenica n. sp. is characterized by a long stylet (more than 120 µm), body length (L = 1,078-1,634 µm; R = 303-362), and lateral field marked by three lateral lines in females and four in males. The lip region is distinctive in that the female labial disc is oval and offset from the first lip region annule, and protrudes markedly; the male labial disc is very large, offset and rectangular, and protrudes distinctly. Hemicycliophora hellenica n. sp. resembles H. megalodiscus Loof by possession of a strongly protruding labial disc, but differs in having a longer female body, more body annules, longer stylet, and dorsally and ventrally indented head annules. The male labial plate is larger than in H. megalodiscus, and the male has four incisures in the lateral field vs. three in H. megalodiscus.     

Terrestrial Nematodes of Alaska I. Trichodoridae (Nemata)

Four species of Trichodoridae, two of them new and belonging to the T. aequalis complex, are reported from Alaska. Trichodorus carlingi n. sp. differs from all other species of the genus in having conspicuously hamate spicules. Vaginal sclerotizations are trapezoidal to rectangular. Trichodorus paucisetosus n. sp., which resembles T. sparsus Szczygiel, 1968 and T. nanjingensis Liu & Cheng, 1990, has sparsely setose, noncephalated spicules partially striated in one or two zones, oval to round vaginal sclerotizations, sperm in discrete spermathecae, and onchiostyle 57-72 μm long. Trichodorus californicus Alien, 1957 is reported from many sites in Alaska, and T. aequalis Allen, 1957 is reported from one site. Trichodorus californicus was collected almost exclusively from glacial refugial regions north of the Alaska Range.     

Ultrastructure of Spermatozoa in the Nematode Halalaimus dimorphus (Nemata: Oxystominidae)

The ultrastructure of spermatozoa in the free-living marine nematode Halalaimus dimorphus was studied with transmission electron microscopy. Spermatozoa in the posterior testis of the male had a large cavity filled with cellular processes, which contained a variable number of small tubules. Mitochondria and small tubules were the only cell structures observed in the cytoplasm. The spermatozoa had a bipolar structure. The anteriorly situated nucleus, which was electron-dense and homogeneous, was surrounded by a single membrane. The size of the small tubules in the cytoplasm (diam. 12-13 nm) and their relatively thick wall structure suggested that they were not normal microtubules (diam. 25 nm). The material of the small tubules was assumed to be major sperm protein (MSP). The cavity appeared to open on the surface of the spermatozoon at the posterior extremity of the cell, and also medially, at the level of the anterior end of the cavity. The pores apparently were closed by a special plug-like structure, which was an evagination of the cell. The wall of the cavity was characterized by longitudinal folds, which were mushroom-shaped in transverse section. Spermatids in the anterior testis of H. dimorphuswere characterized by fibrous bodies packed with small tubules and by cellular processes also containing small tubules. H. dimorphus sperm seem to perform swimming movements based on liquid currents commonly present in turbin-like systems. Spermatogenesis resembled that found in ticks.