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.     

Descriptions of Two New Species of Tylenchorhynchus Cobb, 1913 (Nematoda: Tylenchida), with Details on Morphology and Variation of T. claytoni

Two new species of plant parasitic nematodes (Tylenchorhynchus quaidi n. sp. and T. tritici n. sp.) from Pakistan are described and illustrated. Tylenchorhynchus quaidi n. sp., from soil around roots of potato (Solanum tuberosum) from an experimental field of NNRC, Karachi, Pakistan, is distinguishable from other species by its peculiar sunken dome-shaped head. Although similar to T. goffarti, it differs by head shape, areolation of lateral field, ratios a (23-28 vs. 29-37) and c (11-14 vs. 13-20), and a vagina that is half sclerotized and half unsclerotized. Tylenchorhynchus tritici n. sp., from soil around roots of wheat (Triticum aestivum) from Campbellpur, Pakistan, is similar to T. ventrosignatus and T. nordiensis. It differs from T. ventrosignatus by a continuous lip region, number of head annules (2-3 vs. 4), coarse body annulation, absence of a wave-like structure near the vulva, and by tail shape and number of tail annules (15-23 vs. 28-32). It differs from T. nordiensis by stylet length (12.4-14.6 vs. 11-13 μm), shape of stylet knobs, number of head annules (2-3 vs. 4), non-areolated lateral field in region of phasmids, and not fusing in posterior third of tail. Morphometrics of Tylenchorhynchus claytoni from soil around stunted maize (Zea mays L.), in Muscatine County, Iowa, and several other populations are given. Detailed morphometric data on T. claytoni based on topotypes collected from type locality and several other populations revealed that this species shows variations in the shape of tail in females, number of tail annules (and sometimes annules extending further back on the terminus, almost being an annulated terminus), position of phasmid, and shape of lip region. The subgenus Bitylenchus is proposed as a new synonym of Tylenchorhynchus and its species referred to the latter genus.     

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.     

New and Known Species of Pratylenchus Filipjev, 1936 (Nematoda: Pratylenchidae) from Haryana,India, with Remarks on Intraspecific Variations

Two new monosexual and one bisexual species Pratylenchus Filipjev, 1936 collected from Haryana state of India are described and illustrated. The primary distinguishing features of these species are Pratylenchus microstylus n. sp.: L = 331-458 μm, spear = 11 or 12 μm; Pratylenchus cruciferus n. sp.: L = 648-793 μm, central core of lateral fields with oblique lines, hemizonid 2-8 annules anterior to excretory pore; Pratylenchus ekrami n. sp.: spear = 11-13 μm, spermatheca oblong, post vulval uterine sac with differentiated cells, tail with 26-40 annules, males abundant. Studies on intraspecific variations of P. cruciferus, P. ekrami, and P. coffeae (Zimmermann, 1898) Goodey, 1951 revealed that spear length and value of ''V'' are the least variable characters. Body length and size of post vulval uterine sac varies to varying degrees in different species. Shape of median bulb in P. ekrami, number of incisures in P. coffeae, and tail shape in P. ekrami and P. coffeae exhibit the greatest amount of intraspecific variations. P. zeae Graham, 1936 and P. thornei Sher & Allen, 1953 are the other species collected during the present studies.     

Description of Tylenchorhynchus thermophilus n. sp. (Nematoda: Tylenchina) from Saltgrass in Death Valley,California

A stunt nematode, Tylenchorhynchus thermophilus n. sp., is described and illustrated from soil collected around roots of saltgrass (Distichlis spicata) in Death Valley, California. It is distinguished from the similar species, T. ewingi, T. mexicanus, and T. mashoodi, in having a longer female body, longer tail with more annules, and larger phasmids. Physical and chemical analysis of soil from saltgrass roots showed it to consist of 71% sand and possess high salinity (salt content of 0.51%) and a pH of 9.3.     

Morphological Observations of Pratylenchus penetrans from Celery and Strawberry in Southern Ontario

Pratylenchus penetrans was obtained from Premier strawberry in Norfolk County and the Niagara Peninsula and from celery in the latter area. Host affected the dimensions of P. penetrans to a greater extent than geographical area in Ontario. Adults of P. penetrans from southern Ontario tended to be smaller than those reported elsewhere. The presence of three lip annules was consistent in the seven populations studied, although in some specimens one of the annules did not entirely encompass the head. Crenations around the tail tip of females of P. penetrans was common in the populations studied. Not all of the morphological characters were proportional in size to length of the females of P. penetrans.     

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.     

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.     

Morphological Differences Between Radopholus citrophilus and R. similis

SEM observations of the external morphology of populations of Radopholus citrophilus and R. similis revealed several diagnostic differences. The cloaco-spicular orifice on males of R. citrophilus had three to seven genital papillae (anterior hypoptygmata), whereas males of R. similis were either smooth or had one or two shorter genital papillae (anterior hypoptygmata). Females of R. citrophilus had four annules in the region of the vulval opening, but R. similis had five annules in the same region. The labial disc and lateral lips appeared to be of diagnostic significance, but these areas were more susceptible to artifacts due to fixation. An unknown population of Radopholus from Puerto Rico with a chromosome number of n = 4 was morphologically similar to R. similis. These morphological differences provide additional support that R. citrophilus and R. similis are distinct species.     

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.     

Description of Thecavermiculatus andinus n.sp. (Meloidoderidae), a Round Cystoid Nematode from the Andes Mountains of Peru

Thecavermiculatus andinus n.sp. is described and illustrated from Oxalis tuberosa originally collected in the vicinity of Lake Titicaca high in the Andes mountains of southern Peru. This new species differs markedly front the other two species in the genus, especially in having a much greater female vulval-anal distance and annules with lined punctation on most of the female body with a lacelike pattern restricted to the posterior portion, particularly at the vulva and anus which do not protrude. Females are essentially spherical with protruding neck, white to yellowish in color, and can easily be mistaken for potato cyst nematodes. Among the dozen or more known weed and crop host plants are potato and eggplant. In order to accommodate this new species, the genus Thecavermieulatus is emended. A key to the species of this genus is presented.     

Two New Species of Epsilonema from South Indopacific (Nemata,Epsilonematidae)

Two new species of Epsilonema are described from coral sand from Polynesia and New Caledonia. Epsilonema exoticum, with ca. 131 annules, is characterized by heterogeneous vacuolar ornamentation, small amphid, and male with small field of tiny copulatory thorns. Epsilonema enigmaticum, with ca. 168 annules and small vacuoles and ridges on the cuticle, differs from all other species of the genus by the number (10-16) of subcephalic setae.     

Description of Tylenchorhynchus qasimii sp. n. with a New Report of T. kegasawai from Pakistan

A new stunt nematode, from soil around the roots of coconut (Cocos nucifera L.) and rice (Oryza sativa L.) from Karachi, Pakistan, is described and illustrated as Tylenchorhynchus qasimii n. sp. This new species is characterized by having females with 3–4 head annules, anteriorly directed stylet knobs, absence of post anal extension, presence of rounded sperm filled spermatheca and conoid to bluntly rounded hemispherical tail terminus. Males are common. Also included is the record of T. kegasawai from around the roots of rice (O. sativa L.), a new report from Sindh, Pakistan.     

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.     

Nematodes Parasitic on Forest Trees: III. Reproduction on Selected Hardwoods

The host-parasite relationships of 13 species of plant parasitic nematodes and five species of hardwoods native to the southeastern United States were tested on greenhouse-grown tree seedlings for 6-10 months. Criteria for parasitism were completion o f life cycle and population increase of nematodes. Belonolaimus longicaudatus, Helicotylenchus dihystera, Scutellonema brachyurum and Tylenchorhynchus claytoni parasitized and reproduced on three or more of the species tested. Hoplolaimus galeatus and Pratylenchus brachyurus parasitized two species, Trichodorus christiei and Criconemoides xenoplax parasitized only red maple. Meloidogyne javanica/Liriodendron tulipifera combination was the only positive root-knot nematode/hardwood host-parasite relationship. Hemicycliophora silvestris, Meloidogyne arenaria, M. incognita, and M. hapla were not parasites of the tree species tested.     

Cuticle Ultrastructure of Criconemella curvata and Criconemella sphaerocephala (Nemata: Criconematidae)

Cuticle ultrastructure of Criconemella curvata and C. sphaerocephala females is presented; males were available only in the second species. Ultrathin sections revealed three major zones: cortical, median, and basal. The cortical zone in the females consists of an external and internal layer. In C. curvata the external layer is trilaminate and at each annule it is covered by a multilayered cap. In C. sphaerocephala the trilaminate layer is lacking and the external cortical layer includes an osmophilic coating. In both species the internal layer consists of alternate striated and unstriated sublayers. The median zone is fibrous with a central lacuna and the zone is interrupted between the annules. The basal zone of the cuticle is striated and narrower between each annule. The cuticle of the C. sphaerocephala male is typical of Tylenchida, except under both lateral fields; the striated layer becomes forked at the first incisure and the innermost two prongs of the fork overlap each other, resulting in a continuous striated band.     

Descriptions of Meloidogyne camelliae n.sp. and M. querciana n.sp (Nematoda:Meloidogynidae), with SEM and Host-Range Observations

Meloidogyne camelliae n.sp. on camellia (Camellia japonica) from Japan and M. querciana n.sp. on pin oak (Quercus palustris) from Virginia, USA, are described and illustrated. M. camelliae n.sp. is distingnishable from other species of the genus especially by its striking perineal pattern having heavy ropelike striae forming a squarish to rectangular outline with shoulders or projections, appearing sometimes ahnost starlike. M. querciana differs from other species by its characteristic perineal pattern round to oval in outline, sometimes with a low arch, and sunken vulva surrounded by a prominent obovate area devoid of striae. M. querciana shows some relationship to M. ovalis, but differs further fxom the latter by longer larvae, absence of annules on head of larvae, and rarity of males. Examination of specimens of M. camelliae n.sp. and M. querciana n.sp. with the scanning electron microscope confirmed observations made by optical microscopy and revealed diagnostic and other structures in greater detail. In greenhouse host tests, M. camelliae infected camellia heavily, showed moderate infection on oxalis, only a trace infection on tomato, and no infection on five other plants tested; and M. querciana attacked pin oak, red oak, and American chestnut heavily, but did not infect nine other test plants. In another test, pin oak seedlings did not become infected when heavily inoculated with and grown in the presence of two populations of M. incognita incognita and one of M. incognita acrita. The common names "camellia root-knot nematode" and "oak root-knot nematode" are respectively proposed for M. camelliae and M. querciana.     

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.