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During a recent inventory survey of the nematofauna of tea plantation at Zhejiang Province, China, Discocriconemella parasinensis n. sp. was detected in the rhizosphere of Camellia sinensis . The new species can be characterized by having the uninterrupted rounded labial disc, en face view showing rectangular-rounded labial plate without submedian lobes, R = 82.6 (80-86), Rex = 22 (21-23), stylet length of 68.3 (59-76) μm, excretory pore located 1-2 annuli posterior to the esophageal bulb, vulva open, postvulval body elongated conoid, and tail conoid with bilobed terminus. Morphologically, the species shares the same lip-type with D. discolabia , D. mauritiensis , D. mineira , D. perseae , and D. sinensis . Phylogenetic relationships of the new species based on D2-D3 expansion segments of 28S, ITS, and 18S rRNA genes revealed that D. parasinensis n. sp. formed a separated clade from other criconematid species, thereby supporting its status as a new species of the genus. The new species showed close phylogenetic relationships with Criconemoides geraerti ., (© 2022 Junxia Li et al., published by Sciendo.)

A stunt nematode species, Quinisulcius curvus , recovered from the rhizosphere of sea randa ( Guettarda speciosa ), is described and characterized herein based on integrative taxonomy. Morphometrics and distribution of all reported populations of Q. curvus are also discussed. The Chinese population of Q. curvus displayed slight variation in stylet length; however, the rest of the characters matches well with the original description. This is the first record of Q. curvus from Hainan, China, and the first molecular characterization for this species. Phylogenetic analysis based on partial 18S, 28S and ITS sequences placed Q. curvus with related stunt nematodes species, but clearly separated from them. The present study expanded the geographic record and provided molecular data on Q. curvus from China., (© 2021 Authors.)

Two stunt nematode species, Geocenamus brevidens and Quinisulcius capitatus , were recovered from the potato growing regions of southern Alberta, described and characterized based on integrative taxonomy. Morphometrics, distribution, and host associations of both species are discussed. The Canadian populations of both species displayed minor variations in morphometrical characteristics (viz., slightly longer bodies and tails) from the original descriptions. The populations of G. brevidens and Q. capitatus species examined in this study are proposed as standard and reference populations for each respective species until topotype specimens become available and molecularly characterized. Phylogenetic analyses, based on partial 18S, 28S, and ITS sequences, placed both species with related stunt nematode species. The present study updates the taxonomic records of G. brevidens and Q. capitatus from a new location, southern Alberta, Canada, and will aid in the decision whether these stunt nematodes should be included in nematode management programs., (© 2021 Authors.)

Three populations of neotylenchid nematodes were isolated in Ningbo, P. R. China, from white pine lumber (Pinus monticola) imported from the USA. The nematodes were morphologically intermediate between Hexatylus and Deladenus. The nematodes were molecularly characterized based on sequences of the rDNA small subunit 18S, large subunit 28S D2/D3, and internal transcribed spacer sequences. The phylogenetic inferences placed the nematodes with other neotylenchid nematodes, i.e., Fergusobia and Rubzovinema. Based on the morphology and phylogenetic analysis, this nematode is described herein as Delatylus andersoni n. gen., n. sp. The new genus/species is characterized by the female body habitus ranging from nonobese to semiobese and from straight to dorsally curved when heat relaxed, cephalic framework with six unequal sized lip sectors, lateral fields having 10 to 12 lines, 4 to 5 guide rings on the stylet, excretory pore posterior to the nerve ring, spermatheca diminished or absent, vulvar opening large, and relative proximity of vulva to the anus. Detailed morphological and molecular characterization of the new genus/species is presented along with the comparison of the related genera.

Populations of Criconemoides parvus , Discocriconemella hengsungica , and Discocriconemella limitanea , isolated in Hangzhou, China from the rhizosphere soil of woody perennials were characterized morphologically and molecularly. The morphometric data of the Chinese populations were compared with populations from other regions of the world. DNA barcoding with the mitochondrial COI gene confirmed conspecificity of Chinese and Costa Rican populations of D. limitanea . Phylogenetic assessment using a near full-length 18S ribosomal DNA sequence provided weak support for a grouping of Criconemoides parvus from China and C. annulatus from western North America. The phylogenetic position of D. hengsungica from China and an unknown species of Discocriconemella from Thailand relative to D. limitanea suggests that the genus Discocriconemella is not monophyletic. The study provides the first record of D. hengsungica in China and confirms the presence of C. parvus previously reported from China. Biogeographic implications of these nematode distributions are discussed., (© The Society of Nematologists.)