Area Of Honshu Research Articles

Extinction Threat to a Previously Undescribed Species of Gall Wasp (Hymenoptera: Cynipidae) and Two Associated Parasitoid Species (Hymenoptera: Braconidae and Eulophidae) on a Threatened Rose.

Diplolepis ogawai Abe and Ide sp. nov. (Hymenoptera: Cynipidae) induces galls on Rosa hirtula (Regel) Nakai (Rosales: Rosaceae), which is endemic to a restricted area of Honshu, the main island of Japan. The gall is induced mainly on the leaf of R. hirtula in spring and the mature gall falls to the ground in early summer. The gall-inducing wasp emerges from the gall on the ground in the following spring, suggesting that D. ogawai is univoltine. From spring to summer, the braconid Syntomernus flavus Samartsev and Ku and the eulophid Aprostocetus sp. are parasitic on the larva of D. ogawai in the gall, and the adult wasp of both parasitoid species emerges from the gall on the ground in summer. For S. flavus, this is the first distribution record in Japan and the first host record. Since R. hirtula is threatened with extinction by succession and deforestation, D. ogawai and its two parasitoid wasp species are considered to be at risk of coextinction with the threatened rose. In the event that the population size of this rose species is further reduced, D. ogawai and its parasitoids may -become extinct prior to the extinction of R. hirtula. To conserve these three wasp species associated with R. hirtula, protection of remnant vegetation where individuals of this threatened rose species grow is necessary.

A new species of the Spirobranchuskraussii complex, S.akitsushima (Annelida, Polychaeta, Serpulidae), from the rocky intertidal zone of Japan.

A new species of Spirobranchus (Annelida: Serpulidae) is described based on specimens collected at the coastal Shonan area of Sagami Bay and the adjacent areas of Honshu, Japan. Spirobranchusakitsushima sp. nov. forms large aggregations in the intertidal rocky zone of warm-temperate Japanese shores. This species was referred to as Pomatoleioskraussii (Baird, 1864) until the monotypic genus Pomatoleios was synonymized with Spirobranchus. This new species is formally described based on morphologically distinct Japanese specimens with supporting DNA sequence data. The calcareous opercular endplate of Spirobranchusakitsushima sp. nov. lacks a distinct talon, but some specimens have a slight rounded swelling on the endplate underside, while in other species of the S.kraussii complex a talon is present, usually extended, and with bulges. We examined sub-fossil tube aggregations of the new species and suggest that such aggregation stranded ashore is a good indicator of vertical land movements (uplift and subsidence) resulting from past events, such as earthquakes, in Honshu, Japan.

Les problèmes géologiques et typologiques des sites paléolithiques dans le Nord-Est du Japon

The northeastern area of Honshu is composed of six departments: Aomori, Iwate, Akita, Miyagi, Yamagata and Fukushima. The study of Paleolithic began in 1927 and has given place to the discovery of the site of Hanaizumi. Subsequently, one pushed the research below on land and the discovery of the first paleolithic site in Iwajyuku happened in 1946. Then, H. Nakagawa took back a success of survey of the geomorphological processes and the ordering of the fluviatile terraces with some layers from the volcano-sedimentary deposit of the Pleistocene in the basin of Kitakami and the one of Mabechi. Therefore, we understood that the archaeological levels of the region contain several sedimentary deposits volcano of quaternary origin from the Mounts Öu. In the basin of Kitakami, one noted the deposit of fall pyroclastic of Aiçra (AT) above the layer of the local volcanic ash from Kurosawajiri. Especially, it is one key of an important layer, the last horizon located under AT and above the tephra of Daïfudô from the local volcano, the pyroclastic stream of Towada and the involution of the layer of the volcanic ash from Kurosawajiri. More than 610 paleolithic sites has been counted in the Northeast.

A trial application of particle-induced X-ray emission analysis to microplastic samples collected from the seashore

Here, we apply 20 MeV particle-induced X-ray emission (PIXE) to elemental analysis of microplastic samples with a diameter of approximately 2 mm, collected from the seashores of the northeastern area of Honshu in Japan. The samples were in a grain form with unwanted elements adhering to their surfaces. The PIXE measurements were conducted in a helium atmosphere. For normalization, the number of K X-rays of the residual gas argon was used instead of the directly measured beam irradiation, and the number of continuous X-rays in the PIXE spectrum was used instead of the mass of each sample. Thirteen elements were identified on the microplastics, among which were toxic chromium and lead. Thus, PIXE analysis is useful for analyzing microplastic samples.

Discoveries of the genera Baeochila and Idiocysta from Japan, with descriptions of two new species (Hemiptera: Heteroptera: Tingidae).

Two lace bug genera, Baeochila Drake Poor, 1937 and Idiocysta China, 1930 (Hemiptera: Heteroptera: Tingidae) are recorded from Japan for the first time, and two new species, B. horvathi sp. nov. and I. takarai sp. nov., are described. The former was collected from the vines of Hedera rhombea (Miq.) Bean (Araliaceae) and the bark of Trachycarpus fortunei (Hook.) H.Wendl. (Arecaceae) in suburbanized areas of Honshu, Shikoku and Kyushu, and the latter was collected from the leaves of Freycinetia formosana Hemsl. (Pandanaceae) in the laurilignosa ecosystem of the Ryukyu Islands. The distribution ranges and host plant relationships of the two new species are discussed. Keys to all species of the two genera and photographs of living individuals for the new species are also presented.

Analysis of Impact On Land Pricing from High-Speed-Rail in Honshu Area

Several decades of High-Speed Rail (HSR) in Japan have generated direct impacts on Japanese’s life regarding reducing short time travel, enabling newly accessible areas, and increasing transport market. This paper discusses the indirect effects of HSR network in Honshu area based on urbanisation sustainability regarding land pricing impacts. This study conducts the quantitative analysis to measure the impact of Shinkansen network in the prefecture with and without HSR stations. The land price data is received since 1983. In this study, four case studies have been highlighted using ANOVA analysis to determine the correlation between each case. Besides, the Least Significant Different (LSD) analysis is used to compare the relationship on each pair later on. The research found that the big cities show no relation to land price with other towns due to the land prices in metropolitan areas had expensive before coming to HSR. And, the LSD analysis results show dramatically different on land price in both cases Osaka – Shimane, and Osaka – Tottori that represent high values of |xi-xj| around 4,500 Yen/m2. But, the comparisons of those cities with Kyoto represents slightly different on land value at 401.74 Yen/m2.

Epidemiology and pathological mechanisms of tick-borne encephalitis.

Tick-borne encephalitis virus (TBEV), a member of the genus Flavivirus within the family Flaviviridae, causes fatal encephalitis with severe sequelae in humans. TBEV is prevalent over a wide area of the Eurasian continent including Europe, Russia, Far-Eastern Asia, and Japan. While it was previously thought that TBEV was not endemic in Japan, the first confirmed case of serologically diagnosed TBE was reported in 1993 in the southern area of Hokkaido Prefecture, Japan. In addition, TBEV has been isolated from dogs, wild rodents and ticks in the area. Our epizootiological survey indicated that endemic foci of TBEV were maintained in Hokkaido and other areas of Honshu. TBEV can be divided into three subtypes based on phylogenetic analyses. The Japanese isolates were classified as the Far Eastern subtype, which causes severe neural disorders with a higher mortality rate up to 30%. However, how viral replication and pathogenicity contribute to the neurological manifestations remains unclear. Recent studies have revealed distinctive mechanisms of TBEV pathogenicity and viral genetic factors associated with virulence. This review discusses the recent findings regarding the epidemiology and pathogenesis of TBEV.

An Increasing Trend in the Early-Winter Precipitation around Japan and Its Relationship with Enhanced Heating over the Tropical Eastern Indian Ocean

This study examines the factors responsible for the long-term changes of winter monsoonal flow around Japan in association with increasing precipitation trends in December along the coastal areas of Honshu (the main island of Japan) facing the Sea of Japan. The precipitation around the tropical eastern Indian Ocean and maritime continent has significantly increased in recent years. Thus, a packet of the stationary Rossby wave associated with the anomalous heating deflects the subtropical jet to the south over the eastern edge of the Eurasian continent. The deflection of the jet gives favorable conditions for the development of a low pressure trough in the lower level on the eastern side, leading to the formation of negative height anomalies near the surface around Japan.

Unveiling the origin of Quercus serrata subsp. mongolicoides found in Honshu, Japan, by using genetic and morphological analyses

AbstractQuercus mongolica is a tree found in temperate deciduous forests in east Asia. In Japan, Q. mongolica var. crispula is commonly found; moreover, an oak whose morphology is similar to that of Q. mongolica var. mongolica of the Asian continent has been found in certain areas of Honshu and Hokkaido. Recently, the oak found in Honshu was described as Q. serrata subsp. mongolicoides (QSM). However, genetic comparison between this oak and Q. mongolica var. mongolica of the Asian continent has not been performed; the origin of QSM is thus unknown. Therefore, we aimed to determine the origin of QSM by conducting nuclear microsatellite (nSSR), chloroplast DNA (cpDNA) and leaf morphology analyses for the three taxa, as well as other congeners. The cpDNA variation overlapped among the three taxa, suggesting low discrimination ability for these taxa. Although morphological congruency was found between QSM and Q. mongolica var. mongolica, results of nSSR analyses showed that QSM contained a genetic admixture of Q. mongolica var. mongolica of the Asian continent and Q. mongolica var. crispula of Japan, bolstering an admixture hypothesis. The nSSR and cpDNA analyses suggested that Q. mongolica var. crispula can be the progenitor of Q. mongolica var. mongolica and harbors the ancestral cpDNA haplotypes. Therefore, we concluded that QSM might have been created by an admixture that likely occurred within Japan between Q. mongolica var. crispula and putative relict Q. mongolica var. mongolica, which might have diverged in or around Japan from Q. mongolica var. crispula during the late Pleistocene.

First record of Triops strenuus Wolf, 1911 (Branchiopoda, Notostraca), a tadpole shrimp of Australian origin, from Japan

Three species of tadpole shrimp, i.e.,Triops granarius(Lucas, 1864),Triops longicaudatus(LeConte, 1846) andTriops cancriformis(Bosc, 1801-1802), have been known from Japan. In this paper the author describes a fourthTriopsspecies (= Triops strenuusWolf, 1911) living in the rice paddies of a southern area of Honshu, the largest of the four main islands of Japan. This species was probably endemic to the Australian continent, and no habitat distribution outside Australia has been reported so far. The impact on the existing ecosystem of Japan is quite unknown, and therefore, it is necessary to announce this intrusion into Japan in order to clarify the invasion route, habitat ecology, and the future measures against this new alien species. This invasion is considered to be caused by the resting eggs brought together with silica sand (imported from Western Australia into Japan for the large-scale beach improvement). The results presented here also describe the phylogenetic relationship with all the Australian species described so far, but also all the knownTriopsspecies of the world, based on the nucleotide sequences of mitochondrial DNA.

Pollution of radiocesium and radiosilver in wharf roach (Ligia sp.) by the Fukushima Dai-ichi Nuclear Power Plant accident

Radionuclide concentrations in wharf roaches inhabiting coastal areas of Honshu, Japan, were investigated in October 2011 and June 2012. Relative high concentrations of 110mAg (2.1–127 Bq kg-wet−1), 134Cs (2.6–61 Bq kg-wet−1), and 137Cs (3.5–92 Bq kg-wet−1) were detected in specimens from the eastern Honshu areas. Significantly lower 137Cs concentrations (0.7–1.6 Bq kg-wet−1) were detected in specimens from western and northern Honshu. The decay-corrected 137Cs concentration was significantly inversely correlated with the distance from the Fukushima Dai-ichi Nuclear Power Plant. Thus, wharf roach may serve as a good bioindicator for monitoring radioactive contamination of its habitats.

Colonization History of the Carrion Beetle Necrophila jakowlewi (Coleoptera: Silphidae) in Japan Inferred from Phylogeographic Analysis

Community compositions in continental islands have been strongly affected by the connection and separation of land via land bridges during the cycle of glacial and interglacial periods. The biota of the Japanese archipelago is a result of colonization from the adjacent mainland of East Asia via land bridges at the north and south that existed during the Pliocene and in glacial periods during the Pleistocene. The carrion beetle Necrophila jakowlewi (Coleoptera: Silphidae) is discontinuously distributed in inland regions of the East Asian mainland, the Korean Peninsula, the central area of Honshu, Japan, and several adjacent islands. This species is thought to have migrated into Japan via the southern land bridge. We conducted phylogenetic and phylogeographic analyses using a partial sequence of the cytochrome oxidase subunit I gene and estimated the divergence times among populations to elucidate the colonization process of N. jakowlewi into Japan. Populations of N. jakowlewi were estimated to have diverged in the Japanese archipelago during the last glacial period, whereas the related species, N.japonica and N. brunnicollis, diverged during the interglacial or the last glacial period. In N. jakowlewi, most haplotypes were unique to separate regions, suggesting that the regional populations have been segregated from one another without gene flow by geographic isolation due to rising sea level after the last glacial period.

Cross-breeding results between Pieris napi from southern area of Hokkaido and Tsugaru area of Honshu(Lepidoptera, Pieridae)

Cross-breeding results between Pieris napi from southern area of Hokkaido and Tsugaru area of Honshu(Lepidoptera, Pieridae)

Reproductive Activity of the Small Japanese field mouse (Apodemus argenteus) in Yamaguchi Prefecture, Japan

The small Japanese field mouse (Apodemus argenteus) is endemic to Japan that is distributed on all of the main islands of Japan, including Hokkaido, Honshu, Shikoku and Kyushu, and on smaller islands larger than approximately 150 km 2 (Nakata et al. 2009). It is widely distributed from lowlands to alpine zones, and is semi-arboreal, feeding mainly on seeds, fruits, and arthropods (Abe et al. 2005). The breeding season of this species varies geographically; reproduction peaks in the summer in Hokkaido and in sub-alpine zones of Honshu (Miyao et al. 1963; Fujimaki 1969; Kimura 1977; Tateishi 2006), in the spring and summer in the lowlands and low montane areas of Honshu (Yukawa 1973; Murakami 1974; Nishikata 1979; Torii and Tanaka 1989; Shibata 2000), and in the winter in Kyushu (Yoshida 1972). In Yamaguchi Prefecture, located in the westernmost part of Honshu, characterization of this species is very limited and its life cycle and breeding season remain unknown. Therefore, this study sought to determine the reproductive activity of the small Japanese field mouse in Yamaguchi Prefecture.

Rainfall Tendency in Winter Sugadairakogen Highlands, Nagano Prefecture

The temporal tendency of winter rain events in the Sugadairakogen Highlands was investigated using 33 years daily records of rainfall/snowfall discrimination at the Sugadaira Montane Research Center, University of Tsukuba, and the characteristics of atmospheric circulation in relation to the precipitation-phase changes were analyzed for 12 precipitation events by simple laser-type disdrometer observations with numerical weather simulations. The frequency of rainy days was 12 % from December to February, and 70 % of the rainy days were accompanied with traveling extratropical cyclones. A long-term increase of the snowfall frequency by extratropical cyclones was observed from November to April. The rainy days did not show a long-term trend. However, the large year-to-year variability of rainy days was significantly correlated with the index of the Pacific Decadal Oscillation. The year with an abrupt increase in the number of rainy days corresponded with the warm winter with less accumulated precipitation amount when the snow cover structure in high elevation areas is likely to be affected by the occurrence of rain. In the five rainfall-only cases and seven rainfall and snowfall cases identified in three winter seasons, rainfall dominant events were accompanied with broad warm-air mass expansion covering Honshu area with various courses of extratropical cyclones. On the other hand, rainfall with snowfall events were accompanied with a cyclone passing along the south coast of Japan or long-ranged cold front, and the precipitation phase changed mostly from rain to snow. In Sugadaira, southerly winds were suppressed before the phase change, and the air temperature stayed around 0 °C. A numerical simulation confirmed that weakening of the wind was due to the barrier effect behind the Echigo mountain range with prevailing east-west component winds by the traveling cyclone. A numerical model successfully simulated the rainfall-only events because the synoptic-scale circulation controlled the broad warm air migration. However, cases of a precipitation shift from rainfall to snowfall were not fully simulated. The causes of the discrepancies between the observation and simulation were discussed from the viewpoint of the low-level air-mass exchanges in the large valleys running in the south-north direction and the occurrence of Foehn in the lee-sides of mountain ranges accompanied with a traveling cyclone.

Disappearance of the folk festival and the traditional community

This is an ethnological study of a traditional annual event held at Kuriyama in Hokkaido called the Banrnochi contest. This contest is a competition over the lifting rice bales by young villagers. In Kuriyama, these contests have been held for more than 100 years ever since the local peasants migrated from mainland Japan. There used to be many similar styles of competition all over Hokkaido, but there has not been any event except that of Kuriyama for at least the last three decades. However the contest at Kuriyama also disappeared in 2003. The reason for its longer existence was a strong bond between people in the traditional agricultural community in the town. Most of the villagers migrated from the same areas of Honshu, Toyoma and Ishikawa, during the decade of 1890-1900. Since then they have lived together and helped each other not only on farming, but also in many aspects of life in their traditional agricultural community, such as religious faith, tax payment, village festivals, welfare for the aged, entertainments and risk preparedness. These social events and community organizations established a stable relationship for the villagers and became parts of their self identity. But on the other hand, the stable relationship made the Banrnochi contest resistant to necessary change following the changes of village lifestyle and so it was abandoned. In this ethnological study the Banrnochi festival, a farming competition in Kuriyama Hokkaido, was observed and the causes of its disappearance were explored through informant interviews

The Influence of Pleistocene Refugia on the Evolutionary History of the Japanese Hare, Lepus brachyurus

We performed a phylogeographic analysis of the Japanese hare, Lepus brachyurus, using the mitochondrial cytochrome b gene (1140 bp). In total, 119 haplotypes were recovered from 197 samples isolated from 82 localities on three main islands of the Japanese archipelago: Honshu, Sikoku, Kyushu, Sado Island and the Oki Islands. Results showed two distinct clades at a genetic distance of 3.5%, equivalent to an estimated 1.2 million years. The two clades, encompassing seven subclades, showed an apparent geographic affinity to Kyushu, Shikoku and the nearby area of Honshu (southern group) by one clade, whereas the other clade covered the remaining area of Honshu (northern group). The landscape shape interpolation analysis exhibited a higher genetic diversity in the southern parts of central Honshu (northern group) and Shikoku and Kyushu regions (southern group), suggesting the existence of multiple geographical origins of population expansion in each clade. The Bayesian skyline plot analysis showed that lineage diversifications occurred about 0.35, 0.20 and 0.05 million years ago (Mya), which coincide closely with the glacial-interglacial cycles during the Pleistocene. Therefore, we suggest that the Japanese hare population once inhabited northern and southern refugia, and subsequently developed several populations through local demographic fluctuations. The present day demarcation in the northern and southern geographic groups is considered to be a temporal remnant of Pleistocene population dynamics and the geographic boundary between them could move or fade away in time.

Latitudinal Variation in Birth Dates of Northern Fur Seals (Callorhinus ursinus) in Captivity

Seasonality of mammalian reproduction is ultimately related to dietary and climatic factors, and the timing of birth is scheduled to optimize offspring survival (Bronson 1985). Reproductive synchrony also represents a strategy that individuals adopt to maximize reproductive success in the course of sociobiological and ecological processes such as sexual selection and predation (Ims 1990). Pinnipeds (seals, walruses and sea lions; Carnivora, Pinnipedia) are distinct from other mammals in having two different phases in their life cycles: reproduction on land (or on ice) and foraging in water. Reproduction in most pinniped species is characterized by tight synchrony of births which ensures that pups are born at the optimal time of year (Atkinson 1997). Seasonality and synchrony of births in pinnipeds then lead to temporal aggregation of postpartum estrus and copulation (Stirling 1975; Boness 1991). Reproductive cycles of female pinnipeds are characterized by embryonic diapause and delayed implantation, a preadaptive feature shared with ursid and mustelid carnivores (Mead 1989; Boyd 1991). Lengths of postimplantation gestation (active gestation) are relatively constant in most pinnipeds (ca. 8 months), and the period of delay in embryo implantation adjusts the length of the whole gestation period and determines the timing of births (Boyd 1991). The northern fur seal (Callorhinus ursinus), a highly polygynous pinniped species, inhabits the North Pacific Ocean, Bering Sea, Okhotsk Sea, and Japan Sea, and breeds on subpolar and temperate islands during summer (Gentry 1998). Their reproduction is characterized by highly synchronized annual cycles (Trites 1992). Synchronization of estrus is linked to monopolizability of receptive females by adult males in terrestrial breeding areas and thus provides a basis for the development of polygyny in this species (Boness 1991). Temte (1985) compared the mean birth dates of two wild populations in Alaska (57°N) and in California (33°N), and postulated that the mean photoperiod of 12.5 h/day in autumn might act as a cue for the implantation and control the synchronization of annual breeding cycles of female northern fur seals. On the contrary, Spotte and Adams (1981) disagreed with the hypothesis of photoperiodic control of reproduction based on the fact that breeding activity of captive northern fur seals captured in Alaska (57°N) and translocated to Connecticut (41°N) was observed in July and August being unaffected by the difference in photoperiod between the two sites. However, their results were inconclusive because they only examined breeding activity by month and their birth records consisted of seven stillbirths that occurred over a period ranging from February to July. Temte (1993) examined birth data of pinnipeds kept in North America, Korea and New Zealand, and found a significant latitudinal gradient of birth timing in California sea lion (Zalophus californianus) and harbor seal (Phoca vitulina). Temte and Temte (1993) further explained that the latitudinal variation of births dates in California sea lions were a response to a common photoperiod (11.5 h/day) before implantation. But Temte (1993) failed to find a significant latitudinal variation in birth timing for northern fur seals due to the small sample size. In Japan, northern fur seals were kept in five aquaria under special permit for domestic law that regulates the capture and possession of this species. In four of the five aquaria, northern fur seals were kept outdoor and exposed to natural photoperiodic conditions (at least during the period from estrus to implantation). These four aquaria were located in two geographical areas with different latitudes: Honshu area (35°N), and Hokkaido area (42–43°N). In this study, we analyze the birth dates of northern fur seals kept in these aquaria to ascertain

Different phylogeographic patterns in two Japanese Silpha species (Coleoptera: Silphidae) affected by climatic gradients and topography

To reveal differences in phylogeographic patterns of flightless insect species occurring in different regions of Japan, we studied the phylogeography and demographic history of Silpha beetles occurring in cool-temperate habitats of two major islands, Honshu and Hokkaido, using sequences of the mitochondrial cytochrome oxidase subunit I (COI) gene. Honshu has a more mountainous topography, and cool-temperate habitats occur discontinuously, whereas Hokkaido, located to the north of Honshu, has more continuous cool-temperate habitats. A species endemic to Honshu, S. longicornis occurs on Honshu, whereas S. perforata occurs on Hokkaido and the East Asian continent. Our results indicate that the ancestors of S. longicornis colonized Honshu via a south-west route c. 0.7 Mya and the species has highly divergent populations in isolated mountainous areas of Honshu, whereas S. perforata colonized Hokkaido via a northern route less than 90 000 years ago and has less divergent geographic populations. During the last glacial period, S. perforata was probably restricted to refugia in southern Hokkaido and later expanded into northern Hokkaido, whereas S. longicornis populations existed in many isolated refugia, probably because of the complex topography of Honshu. Thus, our study demonstrates that, even between closely related species, interactions among biology, latitudinal climatic gradients and topography can produce different phylogeographic patterns. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 452–467.

14C Measurements of Tree Rings of a Japanese Cedar During 1945 to 2000 and Core Sampling for Environmental Studies

Japanese cedar rings sampled from Aomori Prefecture, Japan, were measured to obtain tree-ring radiocarbon data covering a period of the latter half of the 20th century in the northernmost area of Honshu (mainland Japan), to obtain records of variation in atmospheric 14C concentration caused by past atmospheric nuclear testing, and to study any possible local effects. This work, carried out on a partial disk, was also intended to provide a reference for data obtained by core sampling of live, standing Japanese black pines as a part of marine environmental studies.