Basilaphelenchus brevicaudatus n. sp., the third species of this apparently rare genus, is described and illustrated. It was recovered from wood and bark samples from a dead forest tree in the Golestan province of northern Iran. It is typologically characterised by female body length (448 (365-492) μm), three lines in the lateral fields, raised cephalic region having a sclerotised vestibule and cephalic framework, stylet thin with delicate conus and thicker shaft, both parts lacking a visible lumen, and with three elongate, backwardly directed knobs, small, spherical to spade-shaped metacorpus with small, posteriorly located valve (at 72 (58-74)% of metacorpus length), simple vulva without flap at 72.5 (69-78)% of body length, post-vulval uterine sac 32.4 (29.0-37.0) μm long, functional rectum and anus, female tail conical, short (c′ = 2.6 (1.9-3.3) in female, and 2.5 (2.3-2.8) in male), dorsally convex and ventrally concave with blunt end or having a small mucron, both forms with a hyaline-like tip. Males common, with well-curved 9.2 (9.0-10.5) μm long spicules measured along the mid-line, three pairs of small caudal papillae (lacking the single P1 ventral papilla) and no bursa at tail tip, but with hyaline region, similar to females. Basilaphelenchus brevicaudatus n. sp. is compared with the two currently known species of the genus, the type species, B. persicus, and B. grosmannae. Molecular phylogenetic inferences using partial sequences of small and large subunit ribosomal RNA genes (SSU and LSU) from different isolates of the new species revealed that it belongs to the Tylaphelenchinae clade.
A new species of Bursaphelenchus, extracted from unprocessed logs of Milicia excelsa from Cameroon and arriving in the port of Leghorn, Tuscany, Central Italy, is described. Bursaphelenchus irokophilus n. sp. is based upon morphological and molecular characters and is characterised by the two-lined lateral field, mitten-shaped spicule possessing cucullus and well-developed and slightly dorsally curved condylus with narrowly rounded tip, female vulva with side flap, and long, smoothly tapering and strongly ventrally recurved female tail. The new species belongs to the abietinus-group and is similar to, but distinguished from, B. abietinus and B. rainulfi by the position of secretory-excretory pore, longer and slender female tail and some morphometric values. In addition, the phylogeny based on SSU and D2-D3 LSU regions shows that this species belongs to the abietinus-group, the relationship among the species of this group being discussed.
Bursaphelenchus rockyi n. sp., isolated in Peking, China, from peat moss imported from Russia, is described. It is characterised by a lateral field with four lines, excretory pore located at the base of the nerve ring or slightly posterior, spicule 15.9 (15.1-17.3) μm long along the chord and with high condylus and a rounded tip, rostrum triangular or conical with bluntly pointed tip, lamina curvature becoming more pronounced at 60% of total length, six caudal papillae with P3 and P4 adjacent to each other, bursa small, starting posterior to P4, vulval lips hemispherical and protruding, and tail conical with finely rounded or mucronated terminus. The new species belongs to the fungivorus-group and is most similar to B. arthuri, B. arthuroides, B. fungivorus and B. seani, but can be distinguished from related species by morphological and sequencing results.
Discocriconemella sinensis n. sp. isolated in Hangzhou, Zhejiang, China, from the rhizosphere of Camellia sinenis is described. The new species was characterised morphologically and molecularly. Important morphological details were elucidated by SEM photographs. The new species is characterised by an uninterrupted rounded cephalic disc, en face showing a rectangular labial plate with slit-like oral apertures, labial plate surrounded by slightly elevated projections resembling rudimentary lobes, R = 66 (64-69), Rex = 21 (17-24), stylet 74 (67-81) μm long, excretory pore located at the base of the pharyngeal bulb, vulva open, tail short and conoid with a lobed terminus. The species belongs to the group 1 lip pattern. Morphologically, it is most similar to D. discolabia, D. mauritiensis, D. mineira and D. perseae. This is the first new Discocriconemella species described from China. Phylogenetic analyses based on analysis of the D2-D3 expansion segments of the 28S rRNA, ITS rRNA, partial 18S rRNA, and COI gene revealed that the new species formed a separate clade from other criconematid species, thereby supporting its status as a new species of the genus. The new species showed close relationships with Criconemoides informis.
Ektaphelenchus cupressi n. sp. was isolated during a survey of nematodes associated with bark samples of a dead cypress tree (Cupressus sempervirens) in Mazandaran province, northern Iran. The new species is characterised by a female body length of 612 (520-693) μm, stylet 17-19 μm long with wide lumen and lacking basal swellings, head region hemispherical in lateral view and slightly offset from the body contour by a shallow constriction, three incisures in the lateral field, excretory pore situated anterior to level of metacorpus valve, hemizonid not seen, post-uterine sac 29-35 μm long, shape of the tail terminus, and arrangement of the male caudal papillae. By a combination of morphological characters, e.g., stylet without knobs or swellings at the base, short conical tail, PUS length, and only a vestigial anus and rectum in most individuals, the new species shares similarities with species belonging to three genera, i.e., Anomyctus, Ektaphelenchus, and Seinura. Phylogenetic analysis based on small subunit (SSU) and partial large subunit (LSU) sequences of rDNA confirmed its status as a new species.
In this study, we describe Labrys fuzhouensis sp. n. based on detailed morphology revealed by scanning electron microscopy and molecular data inferred from 18S and 28S rRNA. The new species differs from other Labrys species by a combination of several morphometric and morphological characters: vulva-anus distance 66-74 μm, tail length 172-182 μm, post-uterine sac 11-12 μm, excretory duct less sclerotised, and hexagon-shaped labial disc. The novelty of L. fuzhouensis sp. n. is also confirmed by multi-dimensional scaling analysis. The 18S and 28S rRNA-based phylogenies suggest that the new species nested in the Labrys clade as sister to L. chinensis. In addition to the new species description, Coslenchus rafiqi is reported from China for the first time, the description being supplemented by the first molecular data (18S and 28S rRNA) for this species.
Longidorus barsii sp. n., from Mt Tara in the Balkan Peninsula, is described and characterised by using a polyphasic approach. The species has numerous males. The female body is 5-7 mm long, rather stout and resembles a large Xiphinema. The lip region is wide, with rounded sides continuous with the neck, frontally flattened and depressed around the oral aperture, amphids are pouch-like and distinctly bi-lobed and the odontostyle is moderately long. The nuclei of the pharyngeal glands are in the normal position, the dorsal nucleus located somewhat posterior to anterior third of bulb. The uteri are long, the distal inner epithelium densely covered with papilla-like outgrowths. The tail is rounded, bluntly conoid and very short. Alpha-numerical identification codes: A4/5, B45, C3, D3, E2, F3, G 1(2), H1, I2, J1, K67. The morphologically most similar species are L. kheirii, L. polyae and L. profundorum. Additional observations are provided on the anterior body region and genital organs in L. barsii sp. n., L. piceicola, L. silvae, and L. uroshis. Selected features are discussed from the taxonomic and functional points of view. The D2-D3 expansion domains of the 28S rRNA gene and the ITS region of L. barsii sp. n. were amplified and sequenced. Phylogenetic analysis using the D2-D3 expansion domains of the 28S rRNA gene revealed close evolutionary relationships with L. polyae, L. athesinus and three unidentified Longidorus spp.
Pasteuria penetrans is a hyperparasite with potential as a biological control agent of root-knot nematodes, Meloidogyne spp. In this study two exotic Pasteuria isolates (PP-3 and PP-J) were developed on different Meloidogyne spp. collected from different districts of Punjab, Pakistan. The development of PP-3 and PP-J on different field populations of Meloidogyne spp. showed differential infectivity in terms of nematode reproduction variables. The development of PP-3 and PP-J was maximum on tomato as compared to cucumber. It was probably due to more invasion sites for nematodes present in the tomato roots. However, a bigger root system has not always been a guarantee for development of Pasteuria on Meloidogyne spp. For successful development of Pasteuria, the key parameters are the percentage of infected females, number of endospores (female)−1 or endospores (mg root powder)−1. The results of these parameters are greater in tomato as compared to cucumber.
The distribution and community structure of plant-parasitic nematodes associated with betel (Piper betle) vine and their relationship with soil chemical properties were investigated in four major growing regions of West Bengal, India. Ordinary kriging method was applied to infer the patterns of spatial distribution of major plant-parasitic nematodes across the growing regions. Meloidogyne and Rotylenchulus were found to be the most abundant genera in betel vine crops in all growing regions. Co-inertia analysis between soil properties and nematode abundance indicated that soil chemical characters significantly affect abundances of plant-parasitic nematodes. The type of betel vine crop (sweet and bitter) also has a significant effect on the abundance of plant-parasitic nematodes, with the highest abundance of Meloidogyne reported from the bitter type of betel crop. Spatial distribution depicted a higher abundance of Meloidogyne throughout the North Bengal growing region. Root-knot and reniform nematodes are two important plant-parasitic nematodes of betel vine that might cause economic yield loss to the growers in West Bengal.
Bark beetles (Curculionidae: Scolytinae) have a significant economic impact on forest stands and agricultural settings in Israel. We focus on nematodes associated with bark beetles collected from different host plants attacked by Scolytinae. The sampling was conducted in forest plantations and fruit tree orchards in several areas in Israel. A total of 430 beetle specimens of eight species were examined for the presence of nematodes. Fifteen nematode species were detected and identified based on molecular and morphological characteristics. Among the examined scolytids, the pine bark beetle, Orthotomicus erosus, the most widely distributed and frequently occurring species in Israel, was accompanied by the highest nematode diversity, with 11 species recovered. Nematode associations with the almond bark beetle (Scolytus amygdali), the olive bark beetle (Phloeotribus scarabaeoides) and the fig bark beetle (Hypoborus ficus) were recorded for the first time. Our study thus supplies novel information on scolytid-associated nematodes in Israel.