New alien and native Ektaphelenchid nematodes (Tylenchomorpha: Ektaphelenchinae) from China with details on host association and geographical distribution

Summary Bark in an empty container from the USA was inspected in Ningbo port, China, and a Devibursaphelenchus population was detected. It was processed and identified as Devibursaphelenchus minor sp. n. The new species is characterised by the lateral field with three incisures, female stylet tripartite, 13.9 (12.7-14.6) μm long without basal thickenings, secretory-excretory pore at the same level as nerve ring or slightly posterior, vagina not sclerotised, vulval lips slightly protruding and vulval flap absent. Post-vulval uterine sac (PUS) not well developed, very short and obscure, extending for half vulval body diam. long, anus and rectum indistinct or absent. Posterior body region conical elongated, gradually narrowing, slightly ventrally curved, ending with a bluntly pointed terminus. Male rare, the spicules are arcuate, separate, 8.2 μm along the chord line, with well-developed condylus, triangular rostrum with finely rounded tip, cucullus or apophysis absent. Tail conical, dorsally convex, ventrally slightly concave with bluntly pointed terminus, ventral bursa not confirmed. Two pairs of genital papillae present. It differs from all other species in this genus by extremely short body length of females and males. Molecular phylogenetic analyses based upon rRNA D2-D3 sequences confirmed it as a new species.

mentioning

confidence: 99%

Detection and identification of Devibursaphelenchus minor sp. n. isolated in the bark from the USA

2023

Redescription of Ektaphelenchoides compsi Baujard, 1984 (Tylenchina: Aphelenchoididae) isolated from Pinus massoniana in Fujian Province, China

Fang

et al. 2021

Summary Ektaphelenchoides compsi is redescribed morphologically with new molecular characterisation. It was isolated from a dead Pinus massoniana tree in Ningde City, Fujian Province, China. Detailed morphology of the spicule, female gonad, hemizonid position, arrangement of male caudal papillae and female tail terminus shape are documented. It is characterised by a lateral field with three lines (forming two bands), tripartite stylet 17.8 (17.0-19.4) μm long without basal thickenings, metacorpus rectangular with anterior 40% granular and posterior part weakly muscular, metacorpal valve slightly posterior to middle of metacorpus, excretory pore at level of nerve ring, vagina with thickened walls and strongly developed muscular bundles, vulval lips slightly protuberant, vulval flap absent, distal region of post-vulval uterine sac appearing as a weakly developed oogonia, anus and rectum indistinct, female posterior part (‘tail’) dorsally convex, conical, terminal region contracted into a bluntly pointed tip. The spicules are arcuate, 15.6 (14.3-16.3) μm along the chord, lamina smoothly curved to distal end, capitulum slightly concave, condylus well-developed with broadly rounded tip and slightly depressed at dorsal end, rostrum triangular with finely rounded tip, cucullus absent, and with seven caudal papillae present. The near full length 18S and 28S D2-D3 regions of rRNA genes sequences were characterised. The phylogenetic analyses revealed that the Fujian population of E. compsi grouped with the Zhejiang population of E. compsi, both being morphologically identical.

Detection and identification of Ektaphelenchoides diversislocis sp. n. isolated from Pinus woodlands of China and Japan

Fang

et al. 2022

Summary Understanding the occurrence and distribution of parasitic nematodes is crucial – some are economic pests, and some are important predators of their insect associates. In our recent nematode inventory survey, two populations of an ektaphelechid nematode were detected in the branches of Pinus trees; later the same nematode population was detected in plant quarantine examinations of wood packaging material imported from Japan. The species was processed and identified as Ektaphelenchoides diversislocis sp. n. The new species can be characterised by having three lateral lines, stylet long and tripartite, excretory pore at the level of nerve ring, comparatively longer post-vulval uterine sac, indistinct rectum and anus. Female posterior body region conical, gradually narrowing, like a mucron or filiform. Male spicule with well-developed condylus, triangular rostrum, and cucullus absent. The species is morphologically and molecularly close to E. compsi. The new species was characterised with near full-length 18S, 28S D2-D3 regions, and internal transcribed spacer (ITS) rRNA genes and mitochondrial cytochrome oxidase I (COI) gene sequences. The species within the Ektaphelenchoides genus are considered to have predatory roles against insect associates; therefore, the discovery of E. diversislocis sp. n. from local and foreign woodlands warrants increased sampling and research attention.