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Ocean Expo Park, established in 1976 on subtropical Okinawa Island, Japan, has approximately 8000 planted or naturally grown trees in an area of 77.2 ha. Windfall of these trees occurs mainly due to typhoons; wood chips made from the trunks and roots of windfall trees are commonly used as mulching material throughout the park areas, despite possible infection by pathogenic fungi such as Phellinus noxius, the pathogen causing brown root rot. P. noxius is distributed in tropical and subtropical areas worldwide and has a broad host range. The fungus can infect host plants with mycelia via root‐to‐root contact or with basidiospores. Here, we report the current status of tree damage caused by brown root rot in the park and infer the infection routes of P. noxius based on microsatellite markers. Among a total of 294 trees surveyed in the park, P. noxius was isolated from 13 trees of five species. P. noxius was observed more frequently on Ficus microcarpa than on other tree species. Ficus superba var. japonica was identified as a new host species, and Bombax ceiba was first recorded as a host plant of P. noxius in Japan. Among the 13 P. noxius isolates from the diseased trees, 2 isolates from adjacent diseased trees were considered to be of the same genet, while the other 11 isolates were different genets, indicating that infection by basidiospores occurred frequently among trees in the entire park, although spread via root systems also occurred between at least two adjacent trees. An identical genet was not detected at distant locations, which suggests that the disease does not spread via chips. However, mulching with chips can lead to wood decay due to decaying fungi other than P. noxius. Therefore, in accordance with the precautionary principle, the park currently prohibits the chipping and mulching of windfall or damaged trees and is considering disposal methods such as burning. [ABSTRACT FROM AUTHOR]

Summary: Two Ruehmaphelenchus species were isolated from the ambrosia beetles Euwallacea kuroshio and E. interjectus , collected from Okinawa and Kagoshima, Japan, respectively. Both nematodes were successfully cultured on a lawn of the grey mould Botrytis cinerea. Morphological observation and molecular characterisation revealed that both species are undescribed; therefore, the nematodes are described herein as R. kuroshioi n. sp. and R. interjectus n. sp. Phylogenetically, both species are closely related to R. formosanus , R. fujiensis , R. digitulus and R. asiaticus. Ruehmaphelenchus kuroshioi n. sp. is characterised by a conical male and female tail, which has a terminal projection (mucron), small male spicule with a weakly-developed triangular condylus, dorsal and ventral limbs that are connected to each other by three different tissues, and clearly separated distal pairs of genital papillae (P3 and P4). However, R. kuroshioi n. sp. can be distinguished from its close relatives by a combination of male and female tail characters and its distinctive phylogenetic status. Ruehmaphelenchus interjectus n. sp. is almost identical to R. formosanus , sharing characteristic lateral spikes of the spicule; they form a well-supported phylogenetic clade. However, R. interjectus n. sp. is distinguished from R. formosanus by morphometric values and ribosomal RNA, i.e. , a 6-bp difference from the ca 1.7 kb molecular sequence of the 18S ribosomal RNA of R. formosanus , which warrants independent species status. [ABSTRACT FROM AUTHOR]

Summary: Steinernema tielingense was found to be widely distributed in Japan. The molecular characteristics of the nematodes isolated from Japan are basically in accordance with those mentioned in the original description of S. tielingense. However, the Japanese isolates are morphologically distinct from the type population by the following characters: length of the infective juvenile, 711 (671-769) μ m, excretory pore of adult males and infective juveniles located posterior mid-pharynx, D% < 50%, smaller H value of 35% and shorter spicules in adult males of both generations. Although discrepancies in morphology and morphometric data between the Chinese isolate and Japanese isolate were observed, the molecular data matched and on this basis the Japanese isolate was identified as being conspecific with S. tielingense. The symbiotic bacterium isolated from the Japanese population of S. tielingense was identified as Xenorhabdus bovienii. [ABSTRACT FROM AUTHOR]

Keywords: Iotonchium cateniforme; Iotonchium laccariae; Iotonchium russulae; molecular; phylogeny; Tylenchomorpha EN Iotonchium cateniforme Iotonchium laccariae Iotonchium russulae molecular phylogeny Tylenchomorpha 1205 1209 5 11/23/21 20211001 NES 211001 I Iotonchium i Cobb, 1920 currently contains 11 species, four of which have been reported in Japan: I I. cateniforme i Tsuda & Futai, 1999, I I. laccariae i Tsuda & Futai, 2005, I I. russulae i Tsuda & Futai, 2005, and I I. ungulatum i Aihara, 2001. The DNA material of I I. cateniforme i , I I. laccariae i , and I I. russulae i was prepared as described previously (Iwahori I et al i ., 2000), and near-full-length of 18S ribosomal RNA (small subunit: SSU) was determined for these three species according to the methods in Iwahori I et al i . According to this classification, I I. ungulatum i and I I. russula i e belong to I Fungiotonchium i , and I I. cateniforme i belongs to I Iotonchium sensu stricto i (Tsuda & Futai, 1999, 2000, 2005; Aihara, 2001). In particular, I I. ungulatum i forms characteristic nematode galls on mushrooms of carnivorous fungi, I Pleurotus i spp. (Tsuda I et al i ., 1996; Tsuda & Futai, 2000). [Extracted from the article]

Summary: Contortylenchus genitalicola is a unique species within the genus. It parasitises the ovary or testis of the longhorn beetle, Monochamus alternatus , and has a neotylenchid-like culturable mycetophagous phase within its life cycle, while the other species in the genus parasitise bark beetles and have a typical unculturable allantonematid life cycle. Because the species was described based solely on morphology, it was necessary to confirm the phylogenetic and taxonomic status of C. genitalicola. A molecular phylogenetic analysis of the species based on ribosomal RNA sequences revealed that C. genitalicola forms a well-supported clade with Contortylenchus spp. isolated from bark beetles, an unidentified allantonematid from Iran, and ' Deladenus cf. laricis ' isolated from the metallic wood-boring beetle, Agrilus macer LeConte (Coleoptera: Buprestidae), in the USA. The generic status of C. genitalicola was supported by phylogenetic analysis, and the analysis also suggests that the diversity of the genus could be higher than currently expected. [ABSTRACT FROM AUTHOR]

Summary: Hirschmanniella diversa and H. imamuri parasitise the lotus, Nelumbo nucifera. Hirschmanniella spp. are the most important pests of lotus cultivation in Japan, but the distribution and species dominancy are not fully understood. In this study, we aimed to collect Hirschmanniella spp. individuals from lotus roots in the major lotus cultivation areas in Japan and identify them morphologically and molecularly using the 18S, D2-D3 regions of rRNA and mitochondrial cytochrome c oxidase subunit I (mtCOI). Hirschmanniella oryzae , commonly known to cause damage on rice in Japan, was also obtained and analysed for inter- and intraspecies sequence variations. All individuals of the genus Hirschmanniella extracted from lotus roots in 16 fields in ten prefectures were identified as H. diversa morphologically and molecularly. This result revealed that H. diversa is a dominant Hirschmanniella species parasitising lotus in Japan. Meanwhile, intraspecific sequence variations in H. diversa were relatively higher in the mtCOI (1-21 bases, ≦5.3%) than in the 18S rRNA and D2-D3 of 28S rRNA (0.0-0.3% and 0.0-0.4%, respectively) and in those of H. oryzae. Based on the mtCOI sequences, five haplotypes were identified and each haplotype was distributed in relatively close regions or regions in which the same lotus cultivars were grown, although further studies are required to verify this assertion. The morphological and genetic variations were higher in H. diversa than in H. oryzae (no intraspecific sequence variation in mtCOI), suggesting that H. diversa was not a recent invasive species. [ABSTRACT FROM AUTHOR]

Lecanosticta acicola is a pine needle pathogen causing brown spot needle blight that results in premature needle shedding with considerable damage described in North America, Europe, and Asia. Microsatellite and mating type markers were used to study the population genetics, migration history, and reproduction mode of the pathogen, based on a collection of 650 isolates from 27 countries and 26 hosts across the range of L. acicola. The presence of L. acicola in Georgia was confirmed in this study. Migration analyses indicate there have been several introduction events from North America into Europe. However, some of the source populations still appear to remain unknown. The populations in Croatia and western Asia appear to originate from genetically similar populations in North America. Intercontinental movement of the pathogen was reflected in an identical haplotype occurring on two continents, in North America (Canada) and Europe (Germany). Several shared haplotypes between European populations further suggests more local pathogen movement between countries. Moreover, migration analyses indicate that the populations in northern Europe originate from more established populations in central Europe. Overall, the highest genetic diversity was observed in south‐eastern USA. In Europe, the highest diversity was observed in France, where the presence of both known pathogen lineages was recorded. Less than half of the observed populations contained mating types in equal proportions. Although there is evidence of some sexual reproduction taking place, the pathogen spreads predominantly asexually and through anthropogenic activity. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]