Description of \u3ci\u3eGracilacus harnicaudata\u3c/i\u3e sp. n. (Nemata : Criconematidae) with Biological and Histopathological Observations

Obese criconematid females and larvae forming colonies were detected under the root cortex attached to the vascular cylinder of redwood roots, Sequoia sempervirens (D. Don) Endl. These specimens have been determined to represent a new species of Criconematidae, Grmilacus lzanzicaudata sp. n. Mature females are obese at midbody but posteriorly the body is constricted and hooked shaped with a rounded tail terminus. Annuli are conspicuous only anteriorly and posteriorly. The cephalic region has four submedian lobes and a circular oral disc. The vulval-lips protrude and the lateral field is marked with four lines. Eggs are partially embedded in a mucoid-like substance. There are giant nutritive cells formed in the parenchyma tissue of the vascular cylinder associated with the nematode colonies. These cells have dense cytoplasm with enlarged nuclei. Starch granules were found inside of these abnormal cells. French language title: Description de Gracilacus hamicaudata sp. n. (Nemata : Cnconenzatidae) et observations sur la biologie et l’histopathologie de cette espèce French language abstract: Des femelles renflées et des juvéniles d’un Criconematide ont été observés, assemblés en colonies, sous le cortex radiculaire et attachés au cylindre central de racines de Sequoia sempervirens (D. Don) Endl. Ils appartiennenàt une nouvelle espèce, Gracilacus hamicaudata sp. n. Les femelles matures sont renflées dans leur partie centrale, mais la partie postérieudreu corps est rétrécie et en forme de crochet, l’extrémité caudale étant arrondie. L‘annélation cuticulaire n’est visible que vers l\u27avant et l’arrière de la femelle. La région céphalique comporte quatre lobes submédians eut n disque oral circulaire. Les lèvres vulvaires sont en relief et le champ latéral comporte quatre lignes. Les oeufs sont en partie entourés par une substance mucoïde. Des cellules nutritives géantes sont formées dans le tissu parenchymatique du cylindre central, en association avec la présence des colonies du nématode. Ces cellules présentent un cytoplasme dense et des noyaux agrandis. Des granules d’amidon ont étě observés à l’intérieur de ces cellules modifiées

Five new species of the family Trischistomatidae (Nematoda: Enoplida) from North and Central America, with keys to the species of Trischistoma and Tripylina

Prado-Vera, Ignacio Cid Del, Ferris, Howard, Nadler, Steven A. (2016): Five new species of the family Trischistomatidae (Nematoda: Enoplida) from North and Central America, with keys to the species of Trischistoma and Tripylina. Zootaxa 4109 (2): 173-197, DOI: http://doi.org/10.11646/zootaxa.4109.2.

FIGURE 5. Trischistoma helicoformis n in Five new species of the family Trischistomatidae (Nematoda: Enoplida) from North and Central America, with keys to the species of Trischistoma and Tripylina

FIGURE 5. Trischistoma helicoformis n. sp. Female A – E. A: Anterior end; B: Vulva region; C: Pharyngeo-intestinal junction; D: Caudal setae lateral view; E: Body shape after death

Five new species of the genus Tripylella (Nematoda: Enoplida: Tripylidae)

Prado-Vera, Ignacio Cid Del, Ferris, Howard, Nadler, Steven A. (2016): Five new species of the genus Tripylella (Nematoda: Enoplida: Tripylidae). Zootaxa 4109 (2): 198-217, DOI: http://doi.org/10.11646/zootaxa.4109.2.

Six new and one known species of Geomonhystera (Nematoda, Monhysteridae) from moss, an epiphytic plant and soil in México and Ecuador

Prado-Vera, Ignacio Cid Del, Ferris, Howard, Subbotin, Sergei A. (2018): Six new and one known species of Geomonhystera (Nematoda, Monhysteridae) from moss, an epiphytic plant and soil in México and Ecuador. Zootaxa 4471 (1): 76-110, DOI: 10.11646/zootaxa.4471.1.

Molecular characterisation of some stubby root nematodes (Nematoda : Trichodoridae) from the USA and other countries

The stubby root nematodes are world-wide distributed polyphagous root ectoparasites and can cause damage to a wide range of crops and natural vegetation. In this study, 22 valid and putative species of stubby root nematodes were identified in 37 samples collected in Malaysia, Mexico, Russia, and the USA (California, Florida, Minnesota and Nevada). The analysis of 58 new sequences of the D2-D3 expansion fragments of 28S rRNA gene revealed the following species: Nanidorus minor from California, Florida and Mexico, N. renifer from Florida, two unidentified Nanidorus species from California and Malaysia, respectively, Paratrichodorus allius from Florida and Minnesota, P. pachydermus and Paratrichodorus sp. from Russia, Trichodorus californicus, T. intermedius,and T. obscurus from California, T. obtusus from Florida, eight unidentified Trichodorus species from California, one unidentified Trichodorus species from Nevada, and two unidentified species of stubby root nematodes, one of Trichodorus and another undetermined species from Mexico. Molecular characterisation of T. californicus, T. intermedius and T. obscurus is given for the first time. The phylogenetic tree reconstructed from the analysis of 108 D2-D3 of 28S rRNA gene sequences of 58 valid and putative species of the stubby root nematodes contained five major clades: i) Trichodorus from Europe, Asia and North America; ii) Nanidorus and Trichodorus from Asia; iii) Trichodorus from California; iv) Paratrichodorus from several distant geographical regions; and v) Monotrichodorus from Central and South America. It has been hypothesised that the California Floristic Province is one of the centres of origin and diversification of stubby root nematodes. There is no information on the economic importance of the stubby root nematode species found in California and Mexico. The confirmation of the occurrence of N. renifer and P. allius in Florida should be of concern for the blueberry and potato industries in the state