Labial Framework Research Articles

Redescription of Basiria gracilis (Thorne, 1949) Siddiqi, 1963 (Rhabditida, Tylenchidae) from South Africa.

Basiria gracilis is redescribed from North West Province, South Africa, associated with willow (Salix sp.), which is a dominant ornamental tree species in the province. B. gracilis is characterised by its female body length (692-994 µm), lateral field with two longitudinal incisures, weakly cuticularised labial framework, high lip region lacking annuli, stylet 8-13 µm long, axial spermatheca filled with small rounded sperm, conical-elongated female tail with round to pointed terminus (103-146 µm, c=6.1-7.4, c'=8.8-12.1). Morphologically, B. gracilis is closely related to B. paragracilis but the taxa are differentiated on the basis of lip region and stylet morphology. In addition, B. gracilis is reported for the first time from South Africa. Line drawings, LM and SEM illustrations are given for the species.

Representing Female Desire Within A Labial Framework of Sexuality

Sexual experiences, rather than being neutral, are specifically male or female. Yet at present no conceptual framework exists for representing female sexual desire. This has resulted in frequent misrepresentations of female sexual experience. To correct this, a labial framework is proposed, not to replace or oppose a phallic framework, but to exist alongside it. The lips of the mouth and those of the genitals provide a felicitous doubling of sexuality and speech to represent female desire and sexual pleasure as labial. Phallic and labial rhythms are organized differently in sexual arousal and desire, since, as Simone de Beauvoir put it, "Man 'gets stiff,' but woman 'gets wet.'" The labial framework therefore represents female psychosexuality more in terms of "wetware" than of "hardware."

Swedish Plectida (Nematoda). Part 3. The genus Loveninema gen. n.

A new genus Loveninema gen. n., with two new species L. tubulosa gen. n., sp. n. and L. unicornis gen. n., sp. n. is de-scribed from bottom sediments collected in Skagerrak off the west coast of Sweden. Loveninema gen. n. is unique amongother genera of Plectida by possessing a midventral labial projection located on the ventral edge of the oral opening andprotruding anteriorly. Other diagnostic characters include: sclerotised labial framework in the shape of a conoid ring withthree projections extending posteriorly: one mid-dorsal, one left-subventral and one right-subventral; papilliform outer la-bial and cephalic sensilla; amphidial fovea a transverse slit located anterior to cephalic sensilla bases; excretory pore open-ing on the ventral side of the labial region; pharynx uniformly muscular, cylindrical; female reproductive systemdidelphic, amphidelphic; male reproductive system monorchic, with reflexed testis; spicules present; gubernaculum pres-ent or absent; either alveolar or tubular supplements present in males, absent in females; caudal glands and spinneret pres-ent. L. tubulosa gen. n., sp. n. is particularly characterised by the 0.66–1.12 mm long body; short midventral labialprojection; straight vagina without sclerotisations; male without alveolar and with 12–15 tubular supplements, 15.0–21.5µm long spicules, and with gubernaculum. L. unicornis gen. n., sp. n. is particularly characterised by the 0.65–0.98 mmlong body; long midventral labial projection; straight vagina without sclerotisations; male with up to 20 alveolar and without tubular supplements, 11.5–14.0 µm long spicules, and without gubernaculum.

First Report of Leipotylenchus abulbosus in Iran.

Leipotylenchus abulbosus (Thorne, 1949) Sher, 1974 belongs to the family Tylenchidae, subfamily Leipotylenchinae, and order Tylenchida. During the spring and autumn months of 2008 to 2010, 80 samples were collected from rhizosphere soil of symptomatic plants including wheat (Tritichum aestivum L.), beet (Beta vulgaris L.), and maize (Zea mays L.) from Meighan and Gavar regions of Markazi Province in central Iran. Plants were dwarfed and leaves were chlorotic. Diseased plants comprised ~7% of all plants in the field. Sandy loam soil was collected from roots up to 15 cm from the base of the plants. Nematodes were extracted from the soil by sieving and centrifugation (3). For species identification, nematodes were transferred to anhydrous glycerin (2) and mounted on slides by the paraffin ring method. Identification was based on morphometric and morphological characteristics of females and males. No other forms of the nematode were isolated from collected samples. L. abulbosus was found in 10% of the collected samples. The nematodes showed typical characteristics of the genus Leipotylenchus: striated and anteriorly flattened lip region, stylet without basal knobs, didelphic gonads, four incisures in lateral fields that were areolated in the posterior portion, presence of deirids and adanal caudal alae, amphid inconspicuous in males. Males contained bursa in tail. Females contained an almost straight body, tapering anteriorly from median bulb and posteriorly beyond the anus; cuticle thick, annules fine. Labial framework was moderately sclerotized. Median bulb with prominent valvular apparatus in the center, oval, occupied two-thirds of the body. Deirids were prominent and at the level of the excretory pore. Vagina a transverse slit at right angles to body axis, extending less than half width into body. Tai1 finely annulated, short, tapering to a narrow tip but becoming broader just before the terminus. Phasmids small in anterior half of the tail. Measurements of 12 females: body length = 1,377 ± 90 (1,276 to 1,469) μm; a = 39.2 ± 1.62 (36.8 to 41.1); b = 7.2 ± 0.34 (6.6 to 8.30); c = 11.1 ± 0.16 (10.7 to 11.3); V% = 52.6 ± 1.42 (50.4 to 53.8); stylet length = 17 ± 0.22 (16.6 to 18) μm; tail length = 124 ± 6.83 (116 to 137) μm); and 7 males: (body length = 1,150 ± 56.84 (1,090 to 1,246) μm; a = 39.5 ± 1.48 (37.5 to 41.5); b = 6.4 ± 0.21 (6.1 to 6.8); c = 9.5 ± 0.06 (9.4 to 9.6); T% = 55.1 ± 0.91 (54.4 to 56.20); stylet length = 17.6 ± 0.36 (17 to 18) μm; tail length = 120 ± 3.77 (115 to 129) μm) conformed to the description of L. abulbosus. L. abulbosus, originally isolated from crop plants in surveyed regions, was cultured on beet (B. vulgaris L.) in the greenhouse. Pure cultures of the nematode were inoculated on beet seedlings at the 4- to 6-leaf stage as described previously (1). Sterilized soils were inoculated with 1,000 infective mature nematodes with three replications. Infection of beet roots by the nematode resulted in leaf chlorosis and reduction in plant height. Previously, L. amiri was collected from soils associated with the roots of onion (Allium cepa L.) plants in Pakistan (4). However there have not been any reports of L. abulbosus in crop plants before. To our knowledge, this is also the first report of L. abulbosus infecting wheat, beet, and maize plants in Iran.

A New Genus of Hoplolaiminae: Plesiorotylenchus Striaticeps N.Gen., N.Sp. (Nematoda: Tylenchida)

The ectoparasite Plesiorotylenchus striaticeps n. gen., n. sp., obtained from the rhizosphere of grapevines at Osman, Turkey, is described. The new genus is close to Rotylenchus Filipjev, 1936, but differs from it and is characterized by the presence of a lip region with longitudinal striae radially disposed and a rectangular labial disc. Plesiorotylenchus n. gen. is considered as Hoplolaiminae because of the short and rounded tail with annulation following its contour, phasmids near anus, strong stylet and labial framework. Bursa not indented terminally. Plesiorotylenchus striaticeps n. sp. is characterized by a truncate lip region in profile with 35-40 longitudinal striae, C-shaped habitus and oesophageal gland overlapping intestine with three gland nuclei.

Three New Tylenchs (Nematoda) From Australia

Tylenchorhynchus tobari n. sp., monosexual, L = 0.61-0.77 mm, V = 51-56, stylet = 17-19 μm, is distinguished by its four-lobed lip region with thin four-lobed disc, narrow body annules with longitudinal striae on neck, cuticular markings in mid ventral line behind vulva, about 50 annules on tail, non-annulated terminus. Tylenchorhynchus velatus n. sp., bisexual, L = 0.66-0.80 mm, V = 51-57, stylet = 22-25 μm, is distinguished by its six-lobed lip region with thin oval disc, vulval sheath about 10 μm long, tail with about 25 annules, annulated terminus. Morulaimus simplex n. sp., bisexual, L = 1.15-1.61 mm, V = 51-59, stylet = 62-74 μm, is distinguished by its continuous lip region less elaborately divided than in other known species, inconspicuous labial framework, prominent sclerotisation behind basal plate, tail with 35-45 annules, terminus annulated.

Comparative Morphology of Six Thornenema Species

A study of specimens of Thornenema cavalcantii, T. mauritianum, T. baldum, T. caudatum, T. longicaudatum and T. qaiseri n. sp. from Australia or Malaysia suggested that T. caudatum, T. longicaudatum, T. wickeni and probably T. loofi, form a group distinct from other species. Differences included narrowed lip region, narrow amphids, spathulate sclerotisation of the labial framework, and unusual spear shape. T. qaiseri n. sp. is described. Specimens of T. cavalcantii included three didelphic females.

Ultrastructural morphology of the body wall, stoma, and stomatostyle of the nematode, Tylenchorhynchus dubius (Bütschli, 1873) Filipjev, 1936

The fine structure of the body wall, stoma, and stomatostyle of the plant parasitic nematode, Tylenchorhynchus dubius, is described. The body wall consists of a six-layered cuticle, about 1 μ thick, and a thin interchordal hypodermis. Some details of the labial framework and the cuticular lining of the stoma are described. The shaft of the stomatostyle is composed of five distinct layers. The attachment between the shaft and the stomatal cuticle is characterized by several specializations. One of these is an extensive attachment complex formed at the lateral junction between the stomatal and stylet epithelia. The protractor musculature consists of three main units which are each subdivided anteriorly into smaller elements. Also present are four secondary muscle elements which extend posteriorly beyond the base of the stylet and attach to the cuticular lining of the esophagus above the dorsal duct orifice.The ultrastructural morphology described for T. dubius is compared with that known for other plant parasitic nematodes. Some likely relationships between structure and function are also discussed.

Pratylenchus macrostylus n. sp. (Pratylenchinae: Nematoda).

Pratylenchus macrostylus n. sp. was found in soil samples collected from around trees in Algonquin Park and Aylen Lake, Ontario, and in Stanley Park, Vancouver, British Columbia, Canada. It has the longest spear in the genus, usually 22 to 24 μ long, with the spear knob flattened on the anterior surface, the lip region roundly convex, generally with two annules. The labial framework is strongly arched and extends into two body annules. The tail is usually conically rounded with variations and the postuterine branch has a vestigial ovary.

Dactylotylenchinae, a new subfamily (Tylenchidae: Nematoda)

A new species of Dactylotylenchus, D. filiformis, was described and more information for D. crassacuticulus Wu, 1968 was presented. The thick cuticle and the digitate sclerotized labial framework of this genus provide the unique character for Dactylotylenchus in the family Tylenchidae. A new subfamily Dactylotylenchinae was created to accommodate this genus.

Dactylotylenchus crassacuticulus, a new genus and new species (Tylenchinae: Nematoda)

Several males and females of an undescribed nematode genus of the subfamily Tylenchinae were found in soil around grass collected from a location not far from Peyto Lake in the Rocky Mountains of Alberta. A new genus and new species, Dactylotylenchus crassacuticulus, is herein described to accommodate this new taxon, which is significantly different from other genera in the subfamily, in possessing a finger-like labial framework and a thick cuticle.

Three New Species of Carcharolaimus (Nematoda: Dorylaimidae)

Carcharolaimus taurus n. sp., about 1.25 mm long, with vulva at 52-53%, has a cuticularised labial framework of 6 sectors, and blunt conoid tail longer than the anal body diameter. The male has 7 ventromedian supplements. C. multicostatus n. sp., about 1 mm long, with vulva at 53-57%, has a cuticularised labial framework with 48 ribs, blunt conoid tail equal in length to the anal body diameter. C. lucidus n. sp., about 1.7 mm long, with vulva at 51-55%, has a cuticularised labial framework of 12 sectors with denticles on the walls, blunt conoid tail equal in length to the anal body diameter; male with 5 to 7 ventromedian supplements. A small muscular bulb is present in the anterior part of the oesophagus of each of these species, most strongly developed in C. multicostatus.