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1.
The ambrosia beetle Platypus quercivorus is a vector for the fungus that causes Japanese oak wilt, and susceptibility to infestation by P. quercivorus varies by tree species. We postulated that P. quercivorus discriminates among host tree species differing in susceptibility to attack. To test this postulate, we counted the number
of flying male beetles (NFM), the number of holes bored by male beetles (NH), and the number of flying female beetles (NFF)
per unit area of bark surface in three fagaceous tree species: Quercus crispula (with high susceptibility to infestation) and Q. serrata and Castanea crenata (both with low susceptibility). NFM and NH were used to calculate the proportion of male beetles that bored holes out of
those that flew to the tree (PBM). We used generalized additive models to predict NFM, NFF, and PBM. The locations of trees,
expressed as x and y coordinates, numbers of weeks after the first male beetle’s flying (WEEK), diameters of trees 130 cm above ground (DBH),
and tree species (SP) were incorporated into the models as candidate explanatory variables. The best-fit models for NFM and
NFF included WEEK and DBH and the effect of location; SP was not included in the models. For PBM, the best-fit model included
WEEK, DBH, and SP. The results indicate that male P. quercivorus prefer Q. crispula to Q. serrata and C. crenata and that selection is made before boring holes on trees, but that P. quercivorus do not discriminate among host species when they fly to trees. 相似文献
2.
The spatial distribution patterns of the attack on fresh logs ofPasania edulis was studied for the oak borer,Platypus quercivorus (Murayama), and two species of Scolytid ambrosia beetles,Xylosandrus crassiusculus (Motschulsky) andXyleborus attenuatus Blanford, in 1994 and 1995. On the logs where onlyP. quercivorus attacked, the entry holes were distributed uniformly when attack intensity was low. However, the distribution pattern became
more aggregated with the increase in attack intensity. On logs where bothP. quercivorus and the two Scolytid species attacked, there was a negative association between the spatial distribution of the entry holes
ofP. quercivorus and that of scolytids. Simultaneous attack of two scolytids also increased the degree of aggregation of the entry holes ofP. quercivorus. The entry holes of scolytids were distributed in groups irrespective of the attack intensity of scolytids andP. quercivorus. These results suggest an asymmetrical interspecific relationship betweenP. quercivorus and scolytids. Concentration of the entry holes ofP. quercivorus in a small area may cause a considerable decline in the reproductive success in the galleries constructed there. 相似文献
3.
To provide evidence for the aggregation ofPlatypus quercivorus (Murayama) (Coleoptera: Platypodidae) in association with the mass mortality of oak trees in Japan, we compared the number
of beetles attracted to oak logs bored by males with the number of beetles attracted to logs that had not been bored. Large
numbers of males and females were attracted to the bored logs, and the total numbers increased as the number of entry holes
in the logs increased. This result shows that both male and female beetles aggregate on logs bored by the males. We collected
a large number of beetles attracted to living trees bored by the beetles, and the total number of beetles collected increased
as the number of entry holes/m2 on the tree trunk increased. Beetles also aggregated on living trees bored by the males. 相似文献
4.
Niche differentiation, in terms of time and space, has been reported within a community of ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) in a tree trunk. Two platypodid ambrosia beetles, Platypus quercivorus (Murray) and Platypus calamus Blandford, utilize a similar height range with respect to the Quercus serrata Murray (Fagaceae) trunk. The sapwood and heartwood (i.e., wood types) are known to differ in their physical and chemical characteristics. The objective of this study was to determine the differences among ambrosia beetles, in terms of wood type preferences, in a Q. serrata tree trunk. We analyzed the horizontal distribution patterns of ambrosia beetles within two mature Q. serrata tree trunks. Platypus calamus and the other ambrosia beetles [P. quercivorus, Ambrosiodmus lewisi (Blandford), Ambrosiophilus atratus Eichhoff, and Xyleborus sp.] showed different horizontal distribution patterns within the wood. The former tended to utilize the heartwood, whereas the latter utilized the sapwood. These results suggest that the wood type can be regarded as one of the niche dimensions of ambrosia beetles in a Q. serrata trunk. 相似文献
5.
The ambrosia beetle Platypus quercivorus causes mass mortality of Fagaceae trees in Japan, and tree species differ in their susceptibility to P. quercivorus. We hypothesized that interspecific differences in susceptibility are caused by differences in beetle infestation patterns,
that is, how many beetles fly to a tree and how many of those arriving bore holes. To examine how tree susceptibility is related
to these parameters, two tree species with different degrees of susceptibility were studied (highly susceptible Quercus crispula and less susceptible Q. salicina). Specifically, we measured the number of male beetles per unit area that flew to the host trees (NFM) and the density of
holes bored by male beetles (DH). From these two values, we calculated the proportion of male beetles flying to a host tree
that bored holes (PBM). These parameters were compared for the two Quercus species. Although the two species did not differ in NFM in 2003, PBM was markedly lower for Q. salicina than for Q. crispula and DH was significantly lower for Q. salicina than for Q. crispula. Thus, the lower susceptibility of Q. salicina is partly explained by its low PBM. 相似文献
6.
Genotype distribution of Raffaelea quercivora in the oak galleries and its composition in the mycangia of Platypus quercivorus 
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下载免费PDF全文 Raffaelea quercivora is the pathogenic fungus that causes Japanese oak wilt. The female monogynous ambrosia beetle, Platypus quercivorus, carries this fungus in mycangia on the pronotum. These beetles bore galleries in oak trees with their partners to produce offspring, and they deposit fungus on the gallery walls from their mycangia. The offspring mature in the gallery, before loading the fungal pathogen and flying from the gallery to other healthy trees. To investigate the unloading and loading modes of the fungus within the gallery, we developed four polymorphic microsatellite markers for R. quercivora and identified the fungal genotypes in the galleries and mycangia of the beetles. Small wood chips were sampled at 5–10‐mm intervals from the walls of five galleries in a dead Quercus serrata tree. The pronota were also sampled from five female adult beetles. The genotypes of the R. quercivora isolates from the wood chips and pronota were identified using the microsatellite makers. The genotypic analysis showed that each gallery was inhabited patchily by 5–10 genotypes of R. quercivora, and the mycangia of each beetle contained 3–6 genotypes. These results indicate that diverse R. quercivora genotypes are unloaded repeatedly from the mycangia of female beetles onto the gallery wall, which results in their patchy distribution on the walls. When the offspring leave the host tree, the fungal clones that proliferate in the walls are also loaded repeatedly into the mycangia of the mature beetles. 相似文献
7.
Naoto Kamata Kojiro Esaki Kenji Mori Hiroyuki Takemoto Toru Mitsunaga Hiroshi Honda 《Journal of Forest Research》2008,13(2):122-126
An ambrosia beetle, Platypus quercivorus, is a vector of Japanese oak wilt, which causes massive mortality of oak trees in Japan. Previous studies have identified
(1S,4R)-4-isopropyl-1-methyl-2-cyclohexen-1-ol ((−)-IMCH) as the major component of the aggregation pheromone of P. quercivorus. We tested the ability of synthetic (−)-IMCH to attract P. quercivorus adults. The synthetic compound attracted 14.4 times as many P. quercivorus, of both sexes, as control traps. Control and (−)-IMCH-baited traps both captured 3.32 times as many males as females, probably
because of the nature of Lindgren funnel traps and of male-biased emergence sex ratio early in the season of adult flights.
(−)-IMCH was proved to be a major component of the aggregation pheromone of P. quercivorus. 相似文献
8.
Dai Kusumoto Hayato Masuya Toshihide Hirao Hideaki Goto Keiko Hamaguchi Wen-I Chou Wiwat Suasa-ard Sawai Buranapanichpan Sopon Uraichuen Oraphan Kern-asa Sunisa Sanguansub Aumporn Panmongkol Thu Pham Quang Sih Kahono Heddy Julistiono Naoto Kamata 《Journal of Forest Research》2014,19(4):404-410
Japanese oak wilt (JOW) has been prevalent in Japan since the late 1980s. Infections of the fungus, Raffaelea quercivora Kubono et Shin. Ito, which is transmitted by an ambrosia beetle [Platypus quercivorus (Murayama)], can cause JOW. Although R. quercivora, P. quercivorus, and oak trees are distributed in other Asia–Pacific countries, the incidence of JOW has not been reported outside Japan. In this study, we collected R. quercivora isolates from 5 Asian countries, including Japan, and compared their ability to induce sapwood discoloration by inoculating Q. serrata logs. The tangential widths of the discoloration in sapwoods inoculated with non-Japanese isolates were equivalent to or greater than those of the 2 Japanese isolates. This indicates that a lack of JOW incidence outside Japan is not because of the lowered ability of R. quercivora to spread discoloration compared with the Japanese isolates. Statistical analyses of the relationship between discoloration and phylogeny based on DNA sequences of actin and chitin synthase showed that the discoloration width was independent of phylogenetic relatedness among the isolates. To discuss why the occurrence of JOW has not been reported outside Japan, further studies (e.g., on host susceptibility and P. quercivorus aggression) throughout Asia are needed. 相似文献
9.
Denny Irawati Shinso Yokota Tomohiro Niwa Yuya Takashima Chisato Ueda Futoshi Ishiguri Kazuya Iizuka Nobuo Yoshizawa 《Journal of Wood Science》2012,58(2):180-183
The chemical characteristics and the suitability for enzymatic saccharification in the spent culture media (SCM) of Auricularia polytricha were examined in order to investigate the utilization of the SCM as a biomass resource for alternative energy production.
Wood meals from 3 hardwood species (Quercus serrata, Betula platyphylla var. japonica, and Alnus japonica) and 2 softwood species (Pinus densiflora and Cryptomeria japonica) were used as basal culture media. Dry weight of fruiting bodies were higher in the cultural media made of B. platphylla var. japonica and A. japonica. Amount of weight loss in media showed almost the same value among the cultural media made of 5 species, except for media
made of C. japonica. The amounts of the main chemical components (Klason lignin, holocellulose, and α-cellulose) in SCM showed lower values than
those in wood meals (WM) and fresh media (FM). After saccharification of the media by Meiselase for 48 h, the hydrolysis weight
decrease dramatically increased in SCM. The amount of glucose in SCM ranged from 10.9 to 19.2 g/100 g dry biomass. The highest
amount of glucose was obtained in the SCM from B. platyphylla var. japonica. These results indicate that SCM of A. polytricha is a suitable biomass material to produce fermentable sugars for bio-ethanol production. 相似文献
10.
Rapid ?ōhi?a Death (ROD) is a fungal disease of ?ōhi?a lehua (Myrtaceae: Metrosideros polymorpha) caused by Ceratocystis lukuohia and C. huliohia. ROD is the aetiological agent of widespread mortality of this important tree on Hawai?i Island, but its epidemiology remains unclear. We investigated the prevalence and viability of C. lukuohia in ambrosia beetle frass in ROD‐affected ?ōhi?a trees. A total of 200 frass traps were placed onto C. lukuohia‐infected ?ōhi?a at four locations on the east side of Hawai?i Island. Frass was collected and screened for the presence of C. lukuohia DNA using a diagnostic qPCR assay. In addition, frass samples were screened for viability by carrot baiting. All trapped beetles were of the genus Xyleborus, with the majority being the non‐native X. ferrugineus. Of the frass samples tested, 62% contained C. lukuohia DNA and 17% of carrot baits were positive for the fungus. These results indicate that ambrosia beetle frass releases C. lukuohia into the environment. We discuss the potential role infested frass could play in the ROD pathosystem. 相似文献
11.
The effects of clear-cutting on the decomposition rate of leaf litter and on nitrogen (N) and lignin dynamics were investigated
in a temperate secondary forest. Decomposition processes were examined over an 18-month period by the litterbag method and
compared between a clear-cut site and an adjacent uncut control site using leaf litter from five dominant tree species (Clethra barvinervis, Quercus serrata, Camellia japonica, Ilex pedunculosa and Pinus densiflora). The decomposition rate for litter from C. barvinervis, Q. serrata and I. pedunculosa was significantly greater in the clear-cut plot than in the control plot, and there was no significant difference between
plots for C. japonica and P. densiflora. Water content of litter was consistently lower in the clear-cut plot than in the control plot. Nitrogen mass increased after
6 months in the control plot, whereas no net increase of N was observed in the clear-cut plot. Nitrogen concentration increased
with respect to accumulated mass loss of litter and was consistently lower in the clear-cut plot for all five species. The
mass of lignin remaining in decomposing litter was generally lower in the clear-cut plot, but lignin concentration in decomposing
litter was not significantly different between the clear-cut and control plots. 相似文献
12.
Keiko Hamaguchi Kenryu Kato Kojiro Esaki Naoto Kamata 《Journal of Forest Research》2011,16(6):518-521
The ambrosia beetle, Platypus quercivorus, is an insect vector for the causal agent of Japanese oak wilt disease, Raffaelea quercivora. We have developed 10 new polymorphic microsatellite markers from Type 1, one of the genetic types of the beetle, using a
biotin-enrichment procedure. Fifty-three adult beetles were used for characterization of the markers. The number of alleles
per locus ranged from two to nine (average 4.9). The observed and expected heterozygosity ranged from 0.49 to 0.77 and from
0.44 to 0.80, respectively. None of the loci deviated significantly from Hardy–Weinberg equilibrium. No linkage disequilibrium
was detected in any pairwise comparisons of loci. Most of the markers successfully amplified in other genetic types of the
beetle. These markers could become useful tools for population genetic studies and for parentage and sibship analysis for
this beetle. 相似文献
13.
We conducted a field experiment to determine whether logs bored by male Platypus quercivorus beetle were less attractive to conspecifics after beetles had mated. Bored (with male beetles) and unbored logs were placed in a beetle-infested forest and enclosed within a cage. For half of the bored logs, female beetles were released to mate with the male beetles. Log attractiveness was determined by assessing the number of beetles captured on adhesive paper placed on each cage enclosing the log. On the logs on which female beetles were released, the number of beetles captured decreased distinctly after release, and did not differ from the number captured on the unbored logs. In contrast, the number of beetles captured on logs with only unpaired males was higher than the number captured on the unbored logs. This result confirms that the attractiveness of logs bored by male P. quercivorus beetles declines after mating occurs. To our knowledge, this is the first evidence for the relaxation of aggregation pheromone following mating for beetles in the subfamily Platypodinae. 相似文献
14.
Takuo Nagaike 《Journal of Forest Research》2010,15(1):65-70
Species composition and community structure of naturally regenerated trees in Larix kaempferi plantations and natural forests were compared in relation to altitudinal gradient. Fifty-nine L. kaempferi plantations and 26 natural forest stands including old-growth and secondary forests were selected from 1300 to 2000 m a.s.l.
in Mt Kushigata of central Japan. Vegetation plots (10 × 10 m) were established in each stand (85 plots in total). Species
composition differed significantly between forest types, particularly on high altitude plots. Some species were significantly
biased to natural forests, while no species were biased to plantations. Although some species that responded significantly
to altitude were common to both forest types (e.g., Acer ukurunduese, Castanea crenata, and Fraxinus lanuginose f. serrata), some differed between forest types (e.g., Fagus japonica, Prunus maximowiczii, and P. nipponica). Thus, plantation management altered species responses to altitude. Altitude should be considered when planning and carrying
out forest ecological restoration in plantations, because species composition of naturally regenerated trees has already been
changed by past plantation management. In particular, attention should be paid to ecological restoration at high altitude. 相似文献
15.
Tadahisa Urano 《Journal of Forest Research》2000,5(3):187-193
This study investigated the number of adults ofPlatypus quercivorus (Murayama) captured on host oak (Quercus spp.) trees, the attack density (the number of entry holes per 100 cm2), and the number of emerging adults to clarify the relationships between the beetle’s colonization on trees in oak stands
and tree mortality. The initial attack ofP. quercivorus, which was the most intense attack, was observed on most living trees simultaneously. Although some attacked trees died within
the year of the attack or in the next year, a high density of attack did not usually cause the death of host trees. Surviving
trees suffered low levels of consecutive attack after the initial attack. BecauseP. quercivorus successfully produced broods only in the dead trees, the population of the insect seems to be maintained only in stands where
oak mortality occurs. However, the adults that landed on most of the surviving trees appeared unable to reproduce probably
due to degradation of host quality. Thus, oak mortality probably ceases within 3 or 4 years after the start of infestation
in a stand, with subsequent reductions in population density of the borer. 相似文献
16.
The aim of this study was to determine and quantify the wood‐decay fungi found on logs of forest tree species (beech, oak, hornbeam, Scots pine and fir) stored in log depots located in six different provinces in the Western Black Sea Region of Turkey. Additionally, it was aimed to determine the natural durability of some important wood species against the most commonly detected wood‐decay fungi. Eighteen families, 31 genera and 45 species belonging to the division Basidiomycota were detected; Antrodia crassa was identified for the first time in Turkey. The abundance of Panus neostrigosus, Polyporus meridionalis, Trametes hirsuta, T. versicolor and Stereum hirsutumincreased significantly with the holding time of the logs (r = 0.99, 0.87, 0.53, 0.57 and 0.78, respectively, p < 0.05). The majority of the fungal species were detected on logs stored in depots for 4–6 years (66%). The percentage of fungal species found on the logs with a holding time of three years or less was 29%, whereas the percentage for those detected on logs stored for seven or more years was 31%. Among the wood species, the greatest number of fungal species (29) and highest amount of fungi (2,539) occurred on beech wood. Natural durability tests showed that T. versicolor caused the greatest loss of wood mass, with an average of 23%. Field studies and natural durability tests performed in the laboratory showed that beech wood lost the most mass among the timber species studied. 相似文献
17.
Winter nitrogen use in deciduous species is largely uncharacterized. We investigated nitrate uptake in the fine roots of a
deciduous oak (Quercus serrata Thunb. ex. Murray). We conducted a 15N-labeling experiment using saplings of Q. serrata in the winter. During three weeks of labeled nitrate application, the concentration of 15N in the fine roots increased significantly. The amount of nitrogen absorbed, as nitrate, was 1.16 ± 1.02 mg N g DW−1, equivalent to 7.6 ± 5.8% of the total nitrogen content. Our results indicate that Q. serrata saplings have significant potential for nitrate uptake in the fine roots in midwinter (i.e., in the absence of leaves). Although
a significant amount of nitrogen applied as nitrate was accumulated, nitrate concentration in the fine roots remained low
during the labeling period. Furthermore, significant nitrate reductase activity was detected. These data suggest that Q. serrata saplings can assimilate nitrate in the fine roots in midwinter. 相似文献
18.
Tsutomu Enoki Takafumi Inoue Naoaki Tashiro Hiroaki Ishii 《Journal of Forest Research》2011,16(4):268-274
We measured the aboveground biomass, biomass increment and litterfall production of a 140-year-old, abandoned Cryptomeria japonica plantation in order to infer the effects of topography on biomass production. The plantation was unsuccessful and the naturally
regenerated broad-leaved trees contributed 93.4% (374.2 Mg ha−1) of the total aboveground biomass (400.2 Mg ha−1). Comparing between different slope positions, aboveground biomass decreased downslope corresponding to the decrease in broad-leaved
tree biomass. The biomass of C. japonica did not vary with slope position. Biomass increment and litterfall production of the broad-leaved trees also decreased downslope.
However, litterfall production per unit biomass and aboveground net primary production per unit biomass increased downslope.
Results of a path analysis showed that biomass increment of C. japonica decreased with increasing topographical convexity, whereas biomass and litterfall production of broad-leaved tree increased.
Litterfall production of broad-leaved tree decreased with increasing biomass of C. japonica, suggesting that, despite their small biomass, the presence of residual C. japonica may have negative effects on the distribution and productivity of the broad-leaved trees. Our results indicated that total
aboveground biomass of the study site was comparable to that of old-growth C. japonica plantations. We inferred that the variation in aboveground biomass of the broad-leaved trees was largely determined by the
topography, while their productivity was affected by interactions with planted C. japonica. 相似文献
19.
To clarify the effects of asynchronous seed production among tree species on the population of seed predators, we investigated
the relationship between the annual variation in production of mature acorns and the insect damage in those acorns of two
sympatric oak species, Quercus variabilis Blume and Quercus serrata Thunb. ex Murray, over 4 years at two study sites. The annual variation in acorn production was noticeable, with a coefficient
of variation (CV) at the two sites of 1.05 and 0.80 for Q. variabilis and 0.87 and 0.73 for Q. serrata. Annual fluctuation in acorn production by Q. serrata was synchronized between the two sites. Since annual fluctuation in acorn production was not synchronized between the two
species, the CVs for the total acorn production by both oak species (0.83 and 0.62 at the two sites) were lower than those
for Q. variabilis and Q. serrata alone. The rate of predation by the specialist predators (Curculio weevils) on the acorns of both species was not related to the annual acorn crop size. Prolonged diapause of Curculio weevils might stabilize their populations. The rate of acorn predation by the generalist predators (tortricid moths) was
also not related to the annual crop size. Asynchronous acorn production by the two oak species would help to stabilize the
population. 相似文献
20.
Microorganisms associated with the oak platypodid beetle,Platypus quercivorus (Murayama), were isolated from the mycangium of adult females, from the proventriculus of adults of both sexes, and from
galleries in the period before dispersal. Fungi isolated from female mycangia were separated into three groups:Raffaelea sp., yeasts (mainlyCandida spp.), and other species.Raffaelea sp. was isolated predominantly from the teneral stage to the dispersal stage, but was not isolated from the mycangia of mother
beetles in new galleries. Yeasts were isolated in every beetle stage tested and their isolation rate was over 80% from the
teneral stage to the dispersal stage. All three fungal groups were found in the female proventriculus.Raffaelea sp. was isolated only in the dispersal stage at a rate of 40%, whereas the isolation rate of yeasts gradually increased beginning
in the mature stage and reached 100% in the rearing stage. In contrast, in the male proventriculus, onlyRaffaelea sp. and yeasts were isolated in the dispersal and rearing stages. The isolation rate in the rearing stage ofRaffaelea sp. was less than 20%, but that of yeasts was 100%, although these rates were almost the same in the dispersal stage.Raffaelea sp. and yeasts were also isolated from cradles containing eclosing pupae. These results suggest thatP. quercivorus acquiresRaffaelea sp. and yeasts in their mycangia from the cradles immediately after eclosion, and maintain them to the dispersal stage. Then,
they transmit these fungi from old to new galleries by way of mycangia, and possibly the digestive system. 相似文献