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1.
A new nematode species was discovered during a diversity survey of plant-parasitic nematodes on turfgrass conducted in North and South Carolina in 2010 and 2011. It is described herein as Hemicaloosia graminis n. sp. and is characterized by two annuli in the lip region, one lateral line, body 610.0–805.0 μm long, stylet 65.0–74.6 μm long, vulva at 84.1% –85.8% of the body , 254–283 annuli, vulva at the 38–53rd annulus from tail terminus, 12–14 annuli between vulva and anus, tail elongate-pointed, 67.5–84.8 μm long in females and spicule straight, 31.0 μm long, caudal alae well developed, two lateral lines in males. The newly described species is morphologically closest to H. paradoxa, but has a longer stylet (65.0–74.6 vs 61.0–65.0 μm) and a higher V-value (84.1–85.8 vs 78.1–84.0%), less RV (38–53 vs 50–56), higher RVan (12–14 vs 10) in females, and a shorter tail (30.1 vs 36.7 μm) and more anteriorly located excretory pore (105.9 vs 140.0 μm) in the male. It was easily differentiated from other species based on near-full-length small subunit rRNA gene (SSU) and ITS1 sequences. Phylogenetic analysis from SSU supports placement in a monophyletic clade with the genus Caloosia. An identification key and a table of distinguishing characteristics are presented for all seven species of Hemicaloosia.  相似文献   

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Summary The family Heteroderidae is revised. On the basis of shared, derived characters sister groups are established and arranged in a phylogenetic tree. A hypothetical, primitive ancestor for the family is defined. The genus Verutus has a large equatorial vulval slit and is considered to be the most primitive form. The genus Meloidodera developed by a reduction in vulval size. Genera which developed later exhibit a subterminally located vulval slit and progressively lost the annulation of the female cuticle. In this process four evolutionary lines emerge: (i) a posterior shift of the vulva and the formation of more or less distinct vulval lips gave rise to the genera Zelandodera and Cryphodera; (ii) changes in the lip configuration of the second-stage juvenile gave rise to the genera Hylonema, Afrodera n.g., Heterodera and Bidera; (iii) changes in the composition of the female cuticle resulted in the genera Thecavermiculatus, Atalodera, Sherodera, Sarisodera and Bellodera n.g. and; (iv) a reduction in vulval slit size led to the development of the genera Dolichodera, Globodera, Cactodera and Punctodera. The genera Ephippiodera and Rhizonema are synonymized with Bidera and Sarisodera respectively. Verutus and Meloidodera are recognized as subfamilies Verutinae and Meloidoderinae and the genera in the four evolutionary lines are recognized as subfamilies Cryphoderinae, Heteroderinae, Ataloderinae and Punctoderinae respectively.Two new genera, Afrodera and Bellodera, are erected for species originally described in Sarisodera and Cryphodera. Both new genera are characterized by a depressed vulval slit and the anus located on the dorsal side of the vulval cone. Differences in lip configuration of the infective juvenile and a postulated difference in female cuticle justifies their placement in different subfamilies. The lip configuration of the infective juveniles in the subfamilies Verutinae, Meloidoderinae, Cryphoderinae, Ataloderinae and Punctoderinae remains basically unchanged. The possible development of this character in the subfamily Heteroderinae is discussed and illustrated. The family Heteroderidae, its six subfamilies and 17 genera are defined or redefined, and for each of the genera the nominal species and their synonyms are listed. New synonyms introduced are: Heterodera rumicis and H. scleranthi of H. trifolii, H. ustinova of Bidera avenae and H. mali of Globodera chaubattia. Cactodera acnidae (Schuster & Brezina, 1979) n. comb. and Dolichodera andinus (Golden, Franco, Jatala & Astogaza, 1983) n. comb. are transferred from Heterodera and Thecavermiculatus respectively. Keys are provided for all taxa for which no suitable keys are available in the literature. Species inquirendae are listed. ac]19840606  相似文献   

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This generic level taxonomic review of the nematode superfamily Aphelenchoidea is based upon a study of specimens from 24 of the 28 described genera. The diagnoses of these genera are presented, and some are emended with new information. One new genus, Huntaphelenchoides, and five new combinations are proposed. The families Paraphelenchidae and Anomyctidae are placed in synonymy with Aphelenchidae and Aphelenchoididae, respectively. The genera Asteroaphelenchoides and Pseudaphelencboides are placed in synonymy under the genus Aphelenchoides. Rare male and/or female specimens of Peraphelenchus, Anomyctus, Laimaphelenchus, Aphelenchus, Cryptaphelenchoides, Megadorus, Tylaphelenchus, and Entaphelenchus, are redescribed and illustrated. Four plates, containing 106 original drawings of the males, females, stylets, and spicules of representatives of 22 aphelenchoid genera, are presented.  相似文献   

6.
Thirty populations of Meloidogyne of diverse geographic origin representing 10 nominal species and various reproductive, cytological, and physiological forms known to exist in the genus were examined to determine their enzymatic relationships. The 184 bands resolved in the study of 27 enzymes were considered as independent characters. Pair-wise comparisons of populations were performed in all possible combinations to estimate the enzymatic distances (ED) and coefficients of similarity (S). A phylogenetic tree was constructed. The apomictic species M. arenaria, M. microcephala, M. javanica, and M. incognita shared a common lineage. M. arenaria was highly polytypic, whereas conspecific populations of M. javanica and M. incognita were largely monomorphic. The mitotic and meiotic forms of M. hapla were very similar (S = 0.93), suggesting that the apomictic race B evolved only recently from the meiotic race A. The five remaining meiotic species (M. chitwoodi, M. graminicola, M. graminis, M. microtyla, and M. naasi - each represented by a single population) were not closely related to each other or to the mitotic species.  相似文献   

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Perry R. N., Wharton D. A. and Clarke A. J. 1982. The structure of the egg-shell of Globodera rostochiensis (Nematoda: Tyienchida). International Journal for Parasitology12: 481–485. The ultrastructure and histochemistry of the egg-shell of Globodera rostochiensis are described. The eggshell consists of an outer vitelline layer, a chitinous layer and an inner lipid layer. The vitelline layer is not unit membrane-like and has strands of particulate material attached to its outer surface. The chitinous layer is made up of fibres consisting of a chitin microfibril core, surrounded by a protein coat. The lipid layer contains lipoprotein membranes. These vary in number, the most commonly observed pattern being two or three membranes loosely associated with the inner surface of the egg-shell.  相似文献   

10.
A new collection of adult anisakid nematodes from the intestine of the catfish Rhamdia guatemalensis from two cenotes (= sinkholes) and a cave in the Yucatan Peninsula, southeastern Mexico, has shown that they are conspecific with those inadequately described as Dujardinia cenotae Pearse, 1936. The female is redescribed and the male is described for the first time. The morphology of this species shows that it belongs to the genus Hysterothylacium. This is the only Hysterothylacium species recorded from freshwater fishes in Mexico and it may well be endemic to cenotes and caves of the Yucatan Peninsula.  相似文献   

11.
Longidorus aetnaeus Roca, Lamberti, Agostinelli & Vinciguerra, 1986 was recovered from the rhizosphere of Quercus cerris L. and Q. pubescens Willd. in north-west Bulgaria. These are new host and geographical records. The morphology and morphometrics of the females were similar to those reported for populations described from Italy. The male, described for the first time, is characterised by having short spicules and two pairs of supplements.  相似文献   

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The infective larva of Litomosoides yutajensis Guerrero et al., 2003, a parasite of the bat Pteronotus pamellii, is described; it is distinct from congeneric infective larvae by the absence of caudal lappets. The life cycles of five other species of Litomosoides are known; three are parasites of rodents, one of a marsupial and one of a bat. As with these species, the experimental vector of L. yutoajensis used was the macronyssid mite Ornithonyssus bacoti. In nature, the main vectors are probably other macronyssids but transmission by O. bacoti, with its large host-range, could account for the characteristic host-switchings in the evolution of Litomosoides. Unlike the murine model L. sigmodontis Chandler, 1931, L. yutajensis is devoid of the endosymbiontic bacteria Wolbachia and may be of great interest.  相似文献   

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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.  相似文献   

16.
Micrographs of the anterior region of 42 species in 36 genera of Tylenchoidea obtained with a scanning electron microscope are presented. Greater detail, depth of focus, and structures not previously seen with the light microscope have been obtained in this study. Some of the implications of the morphology of the face view on the classification of the rlylenchoidca are discussed.  相似文献   

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Summary Tylenchorhynchus microconus n.sp. from around roots of Australian acacia in West Bengal, India has females 0.46–0.65 mm long with coarse body annules, 15–18 m long spear with conus less than half its total length and a short conoid tail (c >1.7–2.8) with 10–15 annules and smooth terminus. T. crassicaudatus leviterminalis n.subsp. differs from T. c. crassicaudatus Williams, 1960 in having a small smooth lip region lacking annules. T. coffeae Siddiqi & Basir, 1959 is fully described from type specimens. ac]19811221  相似文献   

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Up‐scaling species richness from local to continental scales is an unsolved problem of macroecology. Macroecologists hope that proper up‐scaling can uncover the hidden rules that underlie spatial patterns in species richness, but a machinery to up‐scale species richness also has a purely practical side at the scales and for the habitats where direct observations cannot be performed. The species–area relationship (SAR) could provide a tool for up‐scaling, but no valid method has yet been put forward. Such a method would have resulted from Storch et al.'s (2012) suggestion that there is a universal curve to which each rescaled SAR collapses, if Lazarina et al. (2013) had not shown that it does not: both arguments were supported by data analyses. Here we present an analytical model for mainland SAR and argue in favour of the latter authors. We identify 1) the variation in mean species‐range size, 2) the variation in forces that drive SAR at various scales, and 3) the finite‐area effect, as the reasons for the absence of collapse. Finally, we suggest a rescaling that might fix the problem. We conclude, however, that ecologists are still far from finding a practical, robust and easy‐to‐use solution for up‐scaling species richness from SARs.  相似文献   

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