Two new insect-associated tylenchids, Sychnotylenchus hibisci n. sp. and Neoditylenchus xiphydriae n. sp. (Tylenchomorpha: Anguinidae), from Japan

Summary We isolated two tylenchid species belonging to the Sychnotylenchinae, Sychnotylenchus hibisci n. sp. and Neoditylenchus xiphydriae n. sp., from the bark beetle Ernoporus corpulentus and wood wasp Xiphydria ogasawarai, respectively. Sychnotylenchus hibisci n. sp. is characterised by its moderately stout body in both male and female, gubernaculum to spicule length ratio of one-third or less, crustaformeria structure composed of four columns with six large, rounded cells, and a broad female tail with a rounded terminus. The new species is closely related to S. ulmi, with which it shares body shape and gubernaculum to spicule length ratio, but is distinguished by the female tail shape and several morphometric values. Neoditylenchus xiphydriae n. sp. is characterised by its oval to leaf-shaped male bursa, male tail tip reaching the distal end of, and protruding beyond the bursa, a long post-vulval uterine sac (PUS), and a conical female tail with a narrowly rounded terminus. The species is typologically similar to N. pinophilus but is distinguished by its male spicule shape, gubernaculum to spicule length ratio, and longer PUS. Phylogenetically, the Sychnotylenchinae belongs under the Anguinidae (superfamily Sphaerularioidea) and is closely related to several Ditylenchus, Neotylenchus, Neomisticius, and Ficotylus species.

Martininema semicordatae n. sp. (Nematoda: Aphelenchoididae) associated with Ficus semicordata in China

Summary A new nematode species was recovered from the syconia of Ficus semicordata from Xishuangbanna Tropical Botanical Garden, Yunnan Province, China. It is described herein as Martininema semicordatae n. sp. and is characterised by having the combined characters of a long post-vulval uterine sac, excretory pore located at nerve ring level, amoeboid sperm, three pairs of subventral papillae on the male tail, rounded male tail tip with mucron, absence of gubernaculum (= apophysis), and a recurved, rose-thorn-shaped spicule lacking a terminal cucullus. Martininema semicordatae n. sp. differs from other sequenced species by differences in the partial small subunit (SSU) rRNA gene and D2-D3 expansion segments of the large subunit (LSU) rRNA gene. Phylogenetic analysis with LSU D2-D3 expansion segment sequences suggested that M. semicordatae n. sp. is clustered in a highly supported monophyletic clade with M. guangzhouense, M. fistulosus and M. baculum, and shares a common ancestor with these three species.

Ficophagus chaozhouensis n. sp. (Nematoda: Aphelenchoididae), an associate of Ficus hirta Vahl var. roxburghii (Miq.) King in China

Summary A new nematode species was recovered from the syconia of Ficus hirta var. roxburghii from Chaozhou, Guangdong, China. It is described herein as Ficophagus chaozhouensis n. sp. and is characterised by possessing the combined characters of a short post-uterine sac, excretory pore located near the head, amoeboid sperm, three pairs of subventral papillae on the male tail, rounded male tail tip with mucron (occasionally swollen), absence of gubernaculum (or apophysis), a blunt rosethorn-shaped spicule without a terminal cucullus, and a digitate rostrum with a broadly squared tip. Ficophagus chaozhouensis n. sp. was separated from other sequenced species by differences in the partial small subunit (SSU) rRNA gene and D2-D3 expansion segments of the large subunit (LSU) rRNA gene. Phylogenetic analysis with LSU D2-D3 expansion segment sequences suggested that F. chaozhouensis n. sp. is clustered in the same highly supported monophyletic clade with F. aculeata, F. maxima and F. yoponensis, and is sister to F. aculeata.

Two new nematode species of the genus Tobrilus Andrássy, 1959 (Nematoda, Triplonchida) from Lake Baikal, Russia

Two new nematode species of the genus Tobrilus Andrássy, 1959 from Lake Baikal are described and illustrated. The first species Tobrilus elginus sp. nov. was found in the littoral zone of Maloye More Bays. The second species Tobrilus juliae sp. nov. dwells on bodies of dead sponges Lubomirskia baicalensis (Pallas, 1776). Tobrilus elginus sp. nov. is most similar to T. amabilis Tsalolikhin, 1974 and T. bekmanae Tsalolikhin, 1975. In contrast to the first species it has a shorter body and spicules, longer gubernaculum and a shorter supplements row. Its body is shorter and thinner, tail and supplement row are shorter and the vulva is more posterior as compared to the second species. The body size of Tobrilus juliae sp. nov. is most similar to T. securus Gagarin & Naumova, 2011 and T. saprophagus Naumova & Gagarin, 2017. From the first of these species it differs by the thinner body, shorter tail, comparatively shorter outer labial setae and shorter spicules. It differs from the second species by a thinner body, shorter male tail and shorter labial setae.

Paractinolaimus persicus sp. n. (Nematoda: Actinolaimidae) from Iran

A new species of the genus Paractinolaimus, namely, Paractinolaimus persicus sp. n., is described. It is characterised by body 2.3–2.6 mm long; low, truncate lip region; four massive, acute onchia; stoma walls covered with sparse tiny denticles; odontostyle 25–28 μm long; well developed, didelphic-amphidelphic female reproductive apparatus; vulva a longitudinal oval pore; absence of advulval papillae; female tail 146–224 µm long (c’ = 3.3–5.9), elongated filiform, curved ventrad, and with acute terminus; male tail convex conoid with blunt terminus; and 17–18 nearly contiguous ventromedian supplements. This species was recovered from the rhizosphere of wild grass. Line drawings, LM and SEM photographs and measurements are provided.

Ficophagus auriculatae n. sp. (Nematoda: Aphelenchoididae), an associate of the Ficus auriculata-complex in China

Summary A new nematode species was recovered from the syconia of Ficus auriculata-complex, including F. auriculata, F. oligodon and F. hainanensis, from Xishuangbanna Tropical Botanical Garden, China. It is described herein as Ficophagus auriculatae n. sp. and is characterised by possessing the combined characters of a short post-uterine sac, excretory pore located between the metacorpus and the stylet basal knobs, testis multi-reflexed, amoeboid sperm, three pairs of subventral papillae on male tail, rounded male tail tip without mucron, absence of gubernaculum (= apophysis) and sickle-shaped spicules with terminal cucullus. Ficophagus auriculatae n. sp. was differentiated from other sequenced species by the partial small subunit rRNA gene and D2-D3 expansion segments of the large subunit rRNA gene. Phylogenetic analysis with the above-mentioned sequences suggested that F. auriculatae n. sp. has a closer relationship with F. fleckeri in the same highly supported monophyletic clade than with the other sequenced Ficophagus and Schistonchus sensu lato species.

Aphelenchoides medicagus n. sp. (Tylenchina: Aphelenchoididae) found in Medicago sativa imported into China from the USA

Summary Aphelenchoides medicagus n. sp. isolated in Ningbo Port, P.R. China, from dried leaves and shoots of Medicago sativa imported from the USA, is described. It is characterised by a lateral field with four lines (three bands), stylet 9.0-12.0 μm long, excretory pore situated at same level as, or slightly posterior, to the nerve ring, vagina sclerotised, female vulval flap absent, post-uterine sac short, spicules 9.2-14.2 μm long (median curved line), rosethorn-shaped, apex and rostrum rounded, poorly developed, female and male tail conical with terminus bearing star-like processes. The new species belongs to the Group 3 category of Aphelenchoides species sensu Shahina. Phylogenetic analyses based on 18S, ITS and 28S D2-D3 of rDNA and mtCOI sequences confirmed its status as a new species and closely related to A. besseyi and A. fujianensis.

Ficophagus curtipes n. sp. (Nematoda: Aphelenchoididae), an associate of Ficus curtipes in China

Summary A new nematode species was recovered from the syconia of Ficus curtipes from Xishuangbanna Tropical Botanical Garden, Yunnan, China. It is described herein as Ficophagus curtipes n. sp. and is differentiated from all currently described species in the genus by the possession of a spicule with a ventrally recurved tip (terminal barb). It is further characterised by possessing a short post-uterine sac, an ovoid spermatheca, presence of crustaformeria, excretory pore located near the head, amoeboid sperm, three pairs of subventral papillae on the male tail, rounded male tail tip without mucron, rose-thorn-shaped spicules without cucullus and absence of gubernaculum (= apophysis). Ficophagus curtipes n. sp. was differentiated from other sequenced species by the partial small subunit rRNA gene and D2-D3 expansion segments of the large subunit rRNA gene. Phylogenetic analyses suggested that F. curtipes n. sp. has a closer relationship with F. benjamina and F. microcarpus in the same highly supported monophyletic clade than to the other sequenced Ficophagus and Schistonchus s.l. species.

Description of Tripylella jianjuni sp. n. (Nematoda: Tripylidae) from New Zealand

Summary Tripylella jianjuni sp. n. (Tripylidae) is described from New Zealand. Females are characterised by a relatively long body (1743 (1675-1860) μm in the female and 1747 (1576-1979) μm in the male), outer labial setae (8-9 μm long) and cephalic setae (4-5 μm long) in a single circle, two large subventral teeth in two adjacent stomatal chambers, relatively short pharynx (b = 5.5 (5.4-5.6) in the female and 5.7 (5.3-6.1) in the male), vulva located slightly anterior to mid-body (V = 44 (43-46)), protuberant lips, and long filiform tail (461 (398-531) μm, c = 3.8 (3.3-4.2) and c′ = 23.2 (18-29) in the female, and 450 (362-511) μm, c = 3.9 (3.6-4.4) and c′ = 19.0 (16.0-20.8) in the male), tail with three ventromedian caudal setae. Males have arcuate spicules 37 (35-41) μm long, gubernaculum straight, 14 (12-16) μm long, three ventromedian supplementary papillae located anterior to the cloacal aperture, and a single plus four pairs of subventral caudal setae located posterior to the cloacal aperture on the tail. Preliminary analyses of phylogenetic relationships within the Triplonchida were done using the SSU and D2-D3 region of LSU DNA sequences.

Description of Stegelletina lingulata sp. n. (Nematoda, Rhabditida, Cephalobidae) from xeric environments in Iran

A new species belonging to the genus Stegelletina, S. lingulata sp. n., is described from xeric natural areas from Iran. It is characterized by having small body (0.51–0.69 mm in females and 0.45–0.64 mm in males), cuticle slightly tessellated especially at anterior end, lateral field with three longitudinal incisures, lips with long acute process at primary axils and three more dentate processes at secondary axils, primary axils with one triangular axillar guard process and secondary axils lacking axillar processes, labial probolae long (9–11 µm) with slender peduncle lacking adaxial expansion and with convergent smooth prongs, stoma, pharynx and reproductive systems cephaloboid, excretory pore at isthmus level, spermatheca 1.1–1.4 times, and post-vulval sac 0.9–1.2 times the corresponding body diameters in length, female rectum 0.6–0.8 times anal body diameter long, female tail conoid (35–47 µm long, c = 14.0–15.6, c' = 2.1–2.7) with fine rounded terminus, male tail conoid, curved ventrad (53–59 µm long, c = 11.0–12.0, c' = 1.9–2.5) with rounded terminus, spicules 31–33 µm long with ventrally straight manubrium and gubernaculum 14–17 µm long. Measurements and illustrations (line drawings, LM and SEM) are provided for this species. In addition, comments on the morphology of the lip region of the species of the genus Stegelletina are included.