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  • Author or Editor: Keiko Hamaguchi x
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Summary

A new aphelenchoidid entomoparasitic nematode was isolated from the body cavity of overwintering individuals of a tenebrionid beetle, Uloma marseuli, collected at Shiga, Japan. The nematode is characterised by its six equal-sized lips forming a dome shape continuous with body contour. It has a moderately thick stylet, with wide lumen, a long two-part long (conus + conophore) and elongate oval or pear-shaped metacorpus with glandular anterior part. The male spicules are separate with a well-developed condylus, triangular rostrum and smoothly and strongly curved calomus-lamina complex. A gubernaculum or apophysis is absent. There are two pairs of papilliform male genital papillae. Females lack a post-vulval uterine sac, have a seemingly vestigial rectum and anus, and conical tail. The combination of the typological characters of the species does not fit any currently accepted aphelenchoidid genus and is somewhat intermediate between the Ektaphelenchinae and Entaphelenchinae. The molecular phylogenetic analysis also suggested that the nematode is close to both Ektaphelenchoides (Ektaphelenchinae) and Peraphelenchus (Entaphelenchinae). Thus, the nematode is described and illustrated as Lenisaphelenchus ulomae n. gen., n. sp. and tentatively placed in the Ektaphelenchinae.

In: Nematology

Summary

Two new Neomisticius species, typologically and phylogenetically close to each other, are described and illustrated from dead Quercus trees and an ambrosia beetle, Platypus quercivorus. The two species share some stylet morphological characteristics, namely, they both possess a long conus occupying more than half of the total stylet length, a long crustaformeria composed of more than 160 cells (eight rows of more than 20 cells each), and a short and broad female tail with a digitate tip. They are distinguished from each other by N. variabilis n. sp. having a wide, spindle-shaped male bursa with a blunt terminus and N. platypi n. sp. having an oval bursa with a rounded terminus. In addition, the males and females of both species have three large rectal glands and the posterior end of the male testis (distal end of the vas deferens) bears three cells that seemingly function as a valve between the vas deferens and the cloacal tube. These characteristics have not been reported in other tylenchids. Currently, the genus contains only three species: the two new species and N. rhizomorphoides, which has a normal stylet with a short conus, a short crustaformeria, and lacks rectal glands and valve cells in the vas deferens. Therefore, the two new species are readily distinguished from N. rhizomorphoides and, based on the previous definition, may even represent a new genus. However, considering their phylogenetic closeness and biological similarities (e.g., association with ambrosia beetles), the generic definition of Neomisticius was emended to include these new species.

In: Nematology

Summary

A new Devibursaphelenchus species isolated from the bark of a dead Quercus aliena, which had been infected and killed by Japanese oak wilt, was collected in Shiga, Japan. The new species is characterised by the relatively large body in males (661-768 μm) and females (893-1071 μm), conspicuous male bursal flap, male spicule with long condylus and wide blade, female post-vulval uterine sac (PUS) 39-54 μm or 1.6-2.3 times the vulval body diam. long, vestigial female anus, and female tail forming a strongly ventrally recurved elongate conoid with bluntly pointed or narrowly rounded terminus. The new species is typologically similar to D. lini, sharing a large body, conspicuous bursal flap, long PUS, and spicule shape, but can be distinguished from it by the absence of variation in the female tail shape, i.e., the tail of the new species is always long and strongly ventrally curved, while the tail shape varies more in D. lini. A previous molecular phylogenetic analysis suggested that the new species is fairly close to D. lini, but can be distinguished from it by the 1.0% (16 bp) difference within 1.6 kb of the 18S and 3.7% (26 bps) difference within 0.7 kb of the D2-D3 LSU ribosomal RNA genes. The newly found nematode is described and illustrated herein as D. alienae n. sp.

In: Nematology

Summary

A new rhabditid entomophilic nematode was isolated from adult Epuraea (Haptoncus) ocularis collected from brown to light brown sap on the trunk of Ulmus parvifolia in Kyoto, Japan. The typological characters of the species, anteriorly opened peloderan bursa with nine bursal rays with the first, fifth, and eighth pairs directed dorsally, very long and two-part spicule with broad tip, and elongate conical female tail, do not fit the current nominal rhabditid genera. While phylogenetic analyses based on the near-full-length small subunit (18S) ribosomal RNA sequence tentatively suggest that the species is the sister of Buetschlinema, the typological and biological characters of the new species clearly differ from that genus, and so a new species is described herein as Chylorhabditis epuraeae n. gen., n. sp.

In: Nematology

Summary

Bursaphelenchus tadamiensis, which was initially isolated from a stag beetle, Dorcus striatipennis, collected from sap flow of Quercus crispula in Fukushima, north-eastern Japan, was re-isolated three times from sap flow of Quercus spp. in western Japan. The re-isolated populations were mostly morphologically consistent with the type population, but the male bursal flap showed high variations in the newly collected populations. Molecularly, the type and new populations showed differences in the internal transcribed spacer region of ribosomal DNA and mitochondrial cytochrome oxidase subunit I gene, suggesting that the species is genetically divided into several local populations. The isolation pattern of B. tadamiensis, i.e., the species was initially isolated from sap flow-associated beetles and subsequently isolated from sap flow, suggests that the species prefers and is adapted to the sap flow environment as its habitat.

In: Nematology