Meloidogyne grahami n. sp. (Meloidogynidae), A Root-knot Nematode on Resistant Tobacco in South Carolina

Meloidogyne grahami n. sp. is described and illustrated from specimens on tobacco (Nicotiana tabacum) originally from Florence, South Carolina. Considered for several years to be only a race of M. ineognita, this new species readily attacks NC-95 tobacco, a variety with resistance to the M. incognita group that is common in the major U.S. tobacco-producing areas. M. grahami n. sp. is related most closely to the three subspecies of the M. incognita group but differs from all of them, especially in its distinctive perineal pattern and larger larvae (av. 421 μm, vs. 385 μm or less). Also, the dorsal esophageal gland orifice of females of M. grahami n. sp. is further from the base of the styler (5 μm) than in M. i. incognita and M. i. acrita. Comments are given on the distribution of this new species.     

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).     

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.     

Meloidogyne incognita wartellei n. subsp. (Meloidogynidae), a Root-knot Nematode on Resistant Soybeans in Louisiana

Meloidogyne incognita wartellei n. subsp, is described and illustrated from roots of soybean (Glycine max L.) near Washington, Louisiana. It is rather limited in distribution in that state, being known at five locations comprising about 60,000 acres. It not only attacks commonly susceptihle soybeans but is a destructive pest on other commercial soybean varieties that are resistant to other forms of the M. incognita group in the area. This new subspecies is related most closely to M. i. incognita and M. i. acrita, but differs especially in the females having a delicate stylet with small, rounded knobs sloping posteriorly; dorsal esophageal gland orific further back (5 μm) from base of stylet; and excretory pore often two to three stylet lengths (sometimes more) from the anterior end. Also, males are often without detectable head annules and with an average stylet length of 22.4 μm. Comments and morphometric data are given on M. i. incognita and M. i. acrita.     

Meloidogyne platani n. sp. (Meloidogynidae), a Root-knot Nematode Parasitizing American Sycamore

Meloidogyne platani n. sp. is described and illustrated from specimens obtained from roots of American sycamore, Platanus occidentalis, in Virginia. This new species shows certain similarities with M. arenaria but differs from it by a number of distinctive characters. The perineal pattern of females is rounded with fine, wavy to zig-zag striae and raised, convoluted striae in the inner lateral line regions. The stylet of females is 16.5 μm long with large, rounded stylet knobs set off from the shaft. Males have a low head cap and smooth head region. The styler length is 22.0 μm, and the stylet knobs are rounded and set off from the shaft. Mean second-stage juvenile length is 443.0 μm, and stylet length is 12.2 μm. The head region of juveniles is not annulated, and the tail has a definite terminus. This nematode causes severe galling and reproduces well on sycamore. Other good hosts include white ash and tobacco cv. NC 95. M. platani n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of approximately 45 (2n).     

Meloidogyne hispanica n. sp. (Nematoda: Meloidogynidae), the 'Seville Root-Knot Nematode'

Meloidogyne hispanica n. sp. is described and illustrated from specimens obtained from peach rootstock, Prunus persica silvestris Batsch, from the Seville district of Spain. The perineal pattern of the female is oval shaped to rectangular with low dorsal arch and often widely spaced lateral lines with fringe-like striae. The stylet, 14.1 μm long, has broad, distinctly set off knobs. Males have a high, rounded head cap that slopes posteriorly. Labial disc and medial lips are fused to form elongate lip structures. The robust styler, 23.5 μm long, has large, rounded knobs that are slightly set off from the shaft. Mean second-stage juveniles length is 392.6 μm. The truncate head region is generally not annulated. The distinctly rounded and raised labial disc and the crescent-shaped medial lips form dumbbell-shaped lip structures. The stylet, 11.1 μm long, has rounded, posteriorly sloping knobs. The slender tail, 46.4 μm long, has large irregular-sized annules in the posterior region and ends in a bluntly rounded tip. Tomato was a good host; tobacco, pepper, and watermelon were poor hosts; cotton and peanut were nonhosts. Meloidogyne hispanica n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of 2n = 33-36. The esterase pattern is unique among Meloidogyne species.     

Description of Globodera ellingtonae n. sp. (Nematoda: Heteroderidae) from Oregon

A new species of cyst nematode, Globodera ellingtonae, is described from soil collected from a field in Oregon. Second-stage juveniles (J2) of the species are characterized by body length of 365-515 μm, stylet length of 19-22.5 μm, basal knobs rounded posteriorly and pointed anteriorly, tail 39-55 μm, hyaline tail terminus 20-32.5 μm, and tail tapering uniformly but abruptly narrowing and constricted near the posterior third of the hyaline portion, ending with a peg-like, finely rounded to pointed terminus. Cysts are spherical to sub-spherical, dark to light brown and circumfenestrate and cyst wall pattern is ridge-like with heavy punctations. Males have a stylet length of 21-25 μm and spicule length of 30-37 μm with a pointed thorn-like tip. Females have a stylet length of 20-22.5 μm, one head annule and labial disc, heavy punctations on the cuticle, and short vulval slit 7.5-8 μm long. Morphologically this new, round-cyst species differs from the related species G. pallida, G. rostochiensis, G. tabacum complex and G. mexicana by its distinctive J2 tail, and by one or another of the following: shorter mean stylet length in J2, females and males; number of refractive bodies in the hyaline tail terminus of J2; cyst morphology including Granek’s ratio; number of cuticular ridges between the anus and vulva; and in the shape and length of spicules in males. Its relationship to these closely related species are discussed. Based upon analysis of ribosomal internal transcribed spacer (ITS) sequences, G. ellingtonae n. sp. is distinct from G. pallida, G. rostochiensis, G. tabacum and G. mexicana. Bayesian and Maximum Parsimony analysis of cloned ITS rRNA gene sequences indicated three clades, with intraspecific variability as high as 2.8%. In silico analysis revealed ITS restriction fragment length polymorphisms for enzymes Bsh 1236I, Hinf I, and Rsa I that overlap patterns for other Globodera species.     

Descriptions of Chitwoodius brasiliensis n.sp., Chitwoodius rusticulus n.sp., and Vancterlindia venata n.sp. (Dorylaimida: Tylencholaimidae: Vanderlindiinae)

Chitwoodius brasiliensis n.sp. is described from soil around plant roots in Vicosa, MG State, Brazil. It has a body 1.9 mm (1.6-2.5) long, odontostyle and odontophore 33 μm (31-37) and 34 μm (31-36) long, respectively, and males with spicules 59-61 μm long. Chitwoodius rusticulus n.sp. from Colombian rain forest differs from other species of the genus in having a weakly muscular anterior part of the oesophagus, a pore-like vulva, and an unsclerotized vagina. Vanderlindia venata n.sp. from lucerne soil in South Kilimanjaro, Tanzania, differs from the type and only other known species of its genus in having a smaller and less slender body (L = 3.34 mm [3.15-3.71], a = 50 [46-53]), odontostyle 2.3-2.5 times lip region width long, and stylet guiding ring located at 1.2-1.4 times lip region width from anterior end.     

Heterodera graminophila n. sp. (Nematoda Heteroderae) from Grass with a Key to Closely Related Species

Heterodera graminophila n. sp., a member of the H. goettingiana group, is described and illustrated from roots of barnyard grass, Echinochloa colonum (L.) Link, in Baton Rouge, La. This new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to H. cyperi Golden, Rau &Cobb, 1962, and H. graminis Stynes, 1971, but differs particularly in having a small, inconspicuous anus without a circum-anal pattern and located about 20% of the cyst length from the vulval cone terminus, and a longer vulval slit averaging 45 μ in length. A key, based on cyst and larval characters, is presented for identification of the 10 Heterodera species in the H. goettingiana group.     

Description of Meloidogyne pini n. sp., a Root-Knot Nematode Parasitic on Sand Pine (Pinus clausa), with Additional Notes on the Morphology of M. megatyla

Meloidogyne pini n. sp. is described from sand pine, Pinus clausa, in Georgia. The perineal pattern of the female has a large cuticular ridge surrounding a deeply recessed perivulval area. The lateral fields are marked by transverse striae. The female stylet is 14.6 μm long, and the knobs are small, rounded, and set off from the straight and narrow shaft. The excretory pore is near the level of the base of the stylet. The labial disc of the male is large, rounded, and fused with the crescent-shaped medial lips. The head region is smooth, the styler is 20.8 μm long, and the cone is more than twice as long as the shaft. The knobs are rounded and set off from the shaft. In the second-stage juvenile, the labial disc, medial lips, and lateral lips form one smooth, continuous, ovoid head cap. Mean juvenile length is 434 μm, stylet length is 12.8 μm, and tail length is 44.4 μm. M. pini n. sp. also parasitizes loblolly and slash pine. Additional morphological details of M. megatyla are presented.     

Description of the Kona Coffee Root-knot Nematode,Meloidogyne konaensis n. sp.

Meloidogyne konaensis n. sp. is described from coffee from Kona on the island of Hawaii. The perineal pattern of the female is variable in morphology, the medial lips of the female are divided into distinct lip pairs, and the excretory pore is 2-3 stylet lengths from the base of the stylet. Mean stylet length is 16.0 μm, and the knobs gradually merge with the shaft. The knobs are indented anteriorly and rounded posteriorly and the dorsal esophageal gland orifice (DEGO) is long, 3.5-7 μm. The morphology of the stylet of the male is the most useful diagnostic character, with 6-12 large projections protruding from the shaft. One medial lip may be divided into distinct lip pairs. A large intestinal caecum often extends nearly to the level of the DEGO. Mean juvenile length is 502 μm, mean stylet length is 13.4 μm, and mean tail length is 58 μm. The tail may be distinctly curved ventrally and the phasmids are located in the ventral incisure about one anal body width posterior to the anus.     

Meloidogyne mayaguensis n. sp. (Meloidogynidae), a Root-knot Nematode from Puerto Rico

Meloidogyne mayaguensis n. sp. is described and illustrated from specimens obtained from galled roots of eggplant, Solanum melongena L., from Puerto Rico. The perineal pattern of females is round to ovoid with fine, widely spaced striae. It has occasional breaks of striation laterally and a circular tail tip area lacking striae. The stylet, 15.8 μm long, has reniform knobs that merge gradually with the stylet shaft. Males have a high, rectangular, smooth head region, not set off from the body contour. The labial disc is continuous with the medial lips which do not slope posteriorly. The styler, 22.9 μm long, has large rounded backward sloping knobs; the shaft is of uneven diameter. Mean body length of second-stage juveniles is 453.6 μm. The truncate head region is not annulated, and the rounded, slightly raised labial disc and the crescentic medial lips form dumbbell-shaped lip structures. The stylet, 11.6 μm long, has rounded, posteriorly sloping knobs. The slender tail, 54.4 μm long, gradually tapers to a bluntly pointed tip. Tomato, tobacco, pepper, and watermelon are good hosts; cotton and peanut are not hosts. M. mayaguensis n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of 2n = 44-45. The enzyme patterns are unique among Meloidogyne species.     

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.     

Effects of Host Resistance on the Fecundity of Globodera rostochiensis

The fecundity of Globodera rostochiensis (R₁A) females that developed on resistant Rosa and susceptible Katahdin potato cultivars were compared. Cysts collected from each cultivar were bulked, separated into four sizes (> 500 μm, 355-500 μm, 250-355 μm, and < 250 μm), and crushed to determine fecundity as measured by viable egg content (VEC). Fewer and generally smaller cysts developed on Rosa than on Katahdin. Although cyst size significantly (P = 0.01) influenced VEC, cyst age (8 or 13 weeks) had no effect. Regardless of size, cysts produced on Rosa contained significantly fewer viable eggs than did cysts produced on Katahdin. The fecundity of progeny from cysts produced on Rosa was significantly reduced compared with that of progeny from cysts produced on Katahdin. After two generations on Katahdin, the VEC of cysts from a population originating from Rosa was significantly less than that of cysts from a population originating from Katahdin, indicating that in the presence of a pure population of G. rostochiensis R₁A, the females that develop on the resistant cultivar Rosa represent a diminished rather than a superior selected population.     

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.     

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.     

Description of Trilineellus clathrocutis n.g., n.sp. (Tylenchorhynchinae: Tylenchida Thorne, 1949) with a Key to Species and Observations on Tylenchorhynchus sensu stricto

TrilineeIlus clathrocutis n.g., n.sp. is described and illustrated. It was found as an associate of corn (Zea mays) in Stockton, Georgia, USA, and is related to a group of Tylenchorhynchus sensu lato species having three lines in nonareolated lateral fields. This new species is closely related to Tylenehorhynehus divittatus Siddiqi 1961, T. sculptus Seinhorst 1963, and T. triglyphus Seinhorst 1963 (syn. T. chonai Sethi & Swarup 1968) Tarjan 1973. It differs from these species primarily by having longitudinal striae on the body. These four species are differentiated from Tylenchorhynchus sensu stricto by having three lateral lines instead of four. They differ from Uliginotylenchus Siddiqi 1971 by having nonareolated lateral fields, fewer than 25 annules on conoid rounded tails, differently shaped gubernacula, nonattenuated stylets, and other distinctive characters. They differ from Triversus Sher 1973 by having the male tail enclosed by the bursa and by having rounded female tails. SEM observations of T. clathrocutis reveal a cuticle deeply cut by longitudinal and horizontal striae and bearing wide (> 2.0 μm) annules. Trilineellus is proposed to accommodate the new species and the three-incisured species still within Tylenchorhynchus. Tylenchorhynchus is thereby the repository for species within Tylenchorhynchinae having four lines in the lateral field, no conspicuous labial disc, and bursa enclosing the male tail.     

Meloidogyne paranaensis n. sp. (Nemata: Meloidogynidae), a Root-Knot Nematode Parasitizing Coffee in Brazil

A root-knot nematode parasitizing coffee in Paran  State, Brazil, is described as Meloidogyne paranaensis n. sp. The suggested common name is Paraná coffee root-knot nematode. The perineal pattern is similar to that of M. incognita; the labial disc and medial lips of the female are fused and asymmetric and rectangular; the lateral lips are small, triangular, and fused laterally with the head region. The female stylet is 15.0-17.5 μm long, with broad, distinctly set-off knobs; the distance from the dorsal esophageal gland orifice (DGO) to the stylet base is 4.2-5.5 μm. Males have a high, round head cap continuous with the body contour. The labial disc is fused with the medial lips to form an elongate lip structure. The head region is frequently marked by an incomplete annulation. The stylet is robust, 20-27 μm long, usually with round to transversely elongate knobs, sometimes with one or two projections protruding from the shaft. The stylet length of second-stage juveniles is 13-14 μm, the distance of the DGO to the stylet base is 4.0-4.5 μm, and the tail length is 48-51 μm. Biochemically, the esterase (F₁) and malate dehydrogenase (N₁) phenotypes are the most useful characters to differentiate M. paranaensis from other species. However, the esterase phenotype appears similar to that of M. konaensis. Reproduction is by mitotic parthenogenesis, 3n = 50-52. In differential host tests, tobacco, watermelon, and tomato were good hosts, whereas cotton, pepper, and peanut were nonhosts.     

Description and SEM Observations of Meloidogyne sasseri n. sp. (Nematoda: Meloidogynidae), Parasitizing Beachgrasses

Meloidogyne sasseri n. sp. is described and illustrated from American beachgrass (Ammophila breviliffulata) originally collected from Henlopen State Park and Fenwick Island near the Maryland state line in Delaware, United States (6). Its relationship to M. graminis, M. spartinae, and M. californiensis is discussed. Primary distinctive characters of the female perineal pattern were a high to rounded arch with shoulders, widely spaced lateral lines interrupting transverse striations, a sunken vulva and anus, and coarse broken striae around the anal area. Second-stage juvenile body length was 554 μm (470-550), stylet length 14 μm (13-14.5), tail length 93 μm (83-115), tapering to a finely rounded terminus. Male stylet length 20 μm (19-21.5), spicule length 33 μm (30-36). Scanning electron microscope observations provided additional details of perineal patterns and face views of the female, male, and J2 head. Wheat, rice, oat, Ammophila sp., Panicum sp., bermudagrass, zoysiagrass and St. Augustinegrass were tested as hosts. Distribution of the species was the coasts of Delaware and Maryland. The common name "beachgrass root-knot" is proposed for M. sasseri n. sp.     

Meloidogyne morocciensis n. sp. (Meloidogyninae), a Root-knot Nematode from Morocco

Meloidogyne morocciensis n. sp. is described from specimens parasitic on peach rootstock from Morocco. This species exhibits a combination of morphological characters similar to M. arenaria, M. incognita, and M. javanica. The perineal pattern of females is oval to squarish with a moderately high to high dorsal arch, and widely spaced, smooth striae; lateral lines are absent. The stylet, 16.5 μm long, has transversely ovoid, set-off knobs. Males have a set-off, annulated head region. The large, rounded labial disc is distinctly demarcated from the crescent-shaped medial lips; lateral lips are absent. The robust stylet, 24.6 μm long, has large, rounded knobs that taper slightly posteriorly. Mean second-stage juvenile (J2) length is 401 μm. The set-offhead region has incomplete annulations; the lip structures are dumbbell shaped. The stylet, 12.3 μm long, has rounded knobs that slope posteriorly. The J2 tail, 52.6 μm long, has irregularly sized annules in the posterior region and ends in a bluntly rounded tip. Tomato, tobacco, pepper, and watermelon are good hosts; cotton and peanut are not hosts. Meloidogyne morocciensis n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of 47-49. Its esterase phenotype is identical with the three-banded phenotype (A3) of M. arenaria.