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1.
Abundant bog oak trunks occur in alluvial deposits of the Raba River in the village of Targowisko (southern Poland). Several of them contain galleries of the great capricorn beetle (Cerambyx cerdo L.). A well-preserved subfossil larva and pupa, as well as adults of this species, are concealed in some of the galleries. These galleries co-occur with boring galleries of other insects such as ship-timber beetles (Lymexylidae) and metallic wood borers (Buprestidae). A dry larva of a stag beetle (Lucanidae) and a mite (Acari) have been found in the C. cerdo galleries. Selected samples of the trunks and a sample of the C. cerdo larva were dated, using radiocarbon and dendrochronological methods, to the period from 45 bc to ad 554; one sample was dated to the period from 799 to 700 bc. Accumulation of the channel alluvia containing the bog oak trunks is synchronous with the Roman Warm Period (late antiquity/Early Mediaeval times). The most recent part of this period correlates with massive accumulations of fallen oak trunks noted from various river valleys in the Carpathian region and dated to ad 450–570. The results indicate that C. cerdo was more abundant within the study area during the Roman Warm Period than it is today.  相似文献   

2.
Fungus-induced galls can attract spore-feeding arthropods as well as gall-feeding ones, resulting in diverse communities. Do large fungal galls support more abundant and diverse arthropod communities than small fungal galls? To address this question, we investigated the structure of the arthropod community associated with bud galls induced by the fungus Melanopsichium onumae on the tree species Cinnamomum yabunikkei (Lauraceae) in central Japan. Thirteen species of arthropods were associated with M. onumae galls. Dominant arthropod species were represented by the larvae of a salpingid beetle (a spore feeder), a nitidulid beetle (a spore feeder), a cosmopterigid moth (a spore feeder), an unidentified moth (a gall tissue feeder), and a drosophilid species (a gall tissue feeder). Arthropod abundance and species richness were positively correlated with gall diameter. The majority of the most abundant species were more frequently found in large galls than in small ones, indicating that large fungal galls, which have more food and/or space for arthropods, could support a more abundant and diverse arthropod community.  相似文献   

3.
Most wood-feeding insects need an association with microbes to utilize wood as food, and some have special organs to store and convey the microbes. We report here the discovery of the microbe-storage organ (mycangium) in stag beetles (Coleoptera: Lucanidae), which develop in decayed wood. The mycangium, which was discovered in the abdomen, is present in all adult females of 22 lucanid species examined in this study, but absent in adult males. By contrast, adult insects of both sexes of selected Passalidae, Geotrupidae, and Scarabaeidae, which are related to Lucanidae, lacked mycangia similar to those of the lucanid species. Yeast-like microbes were isolated from the mycangium of five lucanid species. DNA sequence analyses indicate that the microbes are closely related to the xylose-fermenting yeasts Pichia stipitis, Pichia segobiensis, or Pichia sp. known from the gut of a passalid species.  相似文献   

4.
以东亚浅海生态系统关键种和重要经济生物——刺参(Apostichopus japonicus)为研究对象,设置380、750和1900 ppm 3个pCO2梯度(实测pH分别为8.06、7.72和7.41),研究CO2驱动的海洋酸化对刺参碳、氮收支的影响。结果显示酸化会抑制刺参对碳、氮生源要素的摄入,pH每降低1个单位,刺参摄取的碳和氮会分别减少40.28 mg/g/d和2.48 mg/g/d;粪便碳、粪便氮、呼吸碳和排泄氮均与pH存在线性正相关关系,而生长碳、氮与pH无线性关系。酸化影响了刺参对碳、氮的分配模式,但用于生长的碳、氮占摄食碳、氮的比例未受影响。研究表明,刺参对海洋酸化具有一定的适应能力,这种适应或许与其较低的钙化程度和在自然条件下pH多变的生境中"提前适应"有关。  相似文献   

5.
The antifungal potential of the pygidial gland secretion of the troglophilic ground beetle Laemostenus punctatus from a cave in Southeastern Serbia against cave-dwelling micromycetes, isolated from the same habitat, has been investigated. Eleven collected samples were analyzed and 32 isolates of cave-dwelling fungi were documented. A total of 14 fungal species were identified as members of the genera Aspergillus, Penicillium, Alternaria, Cladosporium, Rhizopus, Trichoderma, Arthrinium, Aureobasidium, Epicoccum, Talaromyces, and Fusarium. Five isolates were selected for testing the antifungal activity of the pygidial gland secretion: Talaromyces duclauxi, Aspergillus brunneouniseriatus, Penicillium sp., Rhizopus stolonifer, and Trichoderma viride. The microdilution method has been applied to detect minimal inhibitory concentrations (MICs) and minimal fungicidal concentrations (MFCs). The most sensitive isolate was Penicillium sp., while the other isolates demonstrated a high level of resistance to the tested agent. L. punctatus has developed a special mechanism of producing specific compounds that act synergistically within the secretion mixture, which are responsible for the antifungal action against pathogens from the cave. The results open opportunities for further research in the field of ground beetle defense against pathogens, which could have an important application in human medicine, in addition to the environmental impact, primarily.  相似文献   

6.
We applied a multi-isotope approach to examine aspects of niche partitioning, competition, and mobility for rodents in the Central Highlands of Madagascar. Specifically, we used carbon (δ13C), nitrogen (δ15N), and strontium (87Sr/86Sr) isotope ratios in bone to investigate diet and mobility for endemic tufted tail rats (Eliurus spp.), and introduced black rats (Rattus rattus) and house mice (Mus musculus) within and outside a fragment of montane humid forest in the Ambohitantely Special Reserve. There was a clear spatial segregation in trapping success for different species: Eliurus was only in the forest interior and edge, Mus only outside of the fragment in a marsh and park housing complex, and Rattus in all habitats except the housing complex. We find only moderate support for mobility of rodents among habitats. Mus may routinely move between the marsh and housing complex. However, regular movement between the forest edge and interior, or between the forest fragment and surrounding grassland is not supported. Taxa appear to target different foods: Rattus tends to feed at a higher trophic level than Eliurus, and Mus consumes some C4 resources. To date, strontium isotopes have been underutilized in ecological research. Here, we show that they are highly complementary to carbon and nitrogen isotope data. Even in localities with relatively uniform underlying geology, it may be possible to distinguish individuals that regularly forage in different habitats.  相似文献   

7.
The southern pine bark beetle guild (SPBG) is arguably the most destructive group of forest insects in the southeastern USA. This guild contains five species of bark beetles (Coleoptera: Curculionidae: Scolytinae): Dendroctonus frontalis, Dendroctonus terebrans, Ips avulsus, Ips calligraphus, and Ips grandicollis. A diverse community of illicit receivers is attracted to pheromones emitted by the SPBG, including the woodborers Monochamus carolinensis and Monochamus titillator (Coleoptera: Cerambycidae). These woodborers have been traditionally classified as resource competitors; however, laboratory assays suggest that larval M. carolinensis may be facultative intraguild predators of SPBG larvae. This study used polymerase chain reaction (PCR)-based molecular gut content analyses to characterize subcortical interactions between M. titillator and members of the SPBG. The half-lives of SPBG DNA were estimated in the laboratory prior to examining these interactions in the field. A total of 271 field-collected M. titillator larvae were analyzed and 26 (9.6?%) tested positive for DNA of members of the SPBG. Of these larvae, 25 (96.2?%) tested positive for I. grandicollis and one (3.8?%) for I. calligraphus. Failure to detect D. terebrans and D. frontalis was likely due to their absence in the field. I. avulsus was present, but primers developed using adult tissues failed to amplify larval tissue. Results from this study support the hypothesis that larval Monochamus spp. are facultative intraguild predators of bark beetle larvae. Additionally, this study demonstrates the capabilities of PCR in elucidating the interactions of cryptic forest insects and provides a tool to better understand mechanisms driving southern pine beetle guild population fluctuations.  相似文献   

8.
 The Australian buprestid beetle Merimna atrata (Coleoptera: Buprestidae) approaches forest fires because its larvae develop in freshly burnt wood. So far nothing is known about possible sensory systems enabling the beetles to detect fires and to cope with the thermal environment close to the flames. We found that M. atrata has two pairs of infrared (IR) organs on the ventrolateral sides of the abdomen. Each IR organ consists of a specialized IR-absorbing area which is innervated by one thermosensitive multipolar neuron. The primary dendritic branches ramify into more than 800 closely packed terminal endings which contain a large number of mitochondria. We called the special morphology of the dendritic region a terminal dendritic mass. The type of IR receptor found in M. atrata is unique in insects and can best be compared with the IR organs of boid snakes. Received: 14 August 2000 / Accepted in revised form: 18 October 2000  相似文献   

9.
Many insects form groups through interactions among individuals, and these are often mediated by chemical, acoustic, or visual cues and signals. In spite of the diversity of soil-dwelling insects, their aggregation behaviour has not been examined as extensively as that of aboveground species. We investigated the aggregation mechanisms of larvae of the Japanese rhinoceros beetle Trypoxylus dichotomus, which live in groups in humus soil. In two-choice laboratory tests, 2nd- and 3rd-instar larvae gathered at conspecific larvae irrespective of the kinship. The ablation of maxillae, which bear chemosensilla, abolished aggregation behaviour. Intact larvae also exhibited aggregation behaviour towards a larval homogenate. These results suggest that larval aggregation is mediated by chemical cues. We also demonstrated that the mature larvae of T. dichotomus built their pupal cells close to a mesh bag containing a conspecific pupal cell, which indicated that larvae utilize chemical cues emanating from these cells to select the pupation site. Thus, the larvae of T. dichotomus may use chemical cues from the conspecifics in two different contexts, i.e. larval aggregation and pupation site selection. Using conspecific cues, larvae may be able to choose suitable locations for foraging or building pupal cells. The results of the present study highlight the importance of chemical information in belowground ecology.  相似文献   

10.
为了探究连续海拔梯度上亚高山-高山草甸群落多样性、碳氮磷化学计量特征及其环境适应策略,以五台山南坡自然分布的亚高山-高山草甸群落为研究对象,沿海拔梯度(2 201~3 011 m)设置9个样地,采用相关性分析、偏冗余分析(pRDA)的方法,分析亚高山-高山草甸群落多样性和碳氮磷化学计量特征及其与环境因子的关系. 结果表明:在五台山南坡2 201~3 011 m海拔范围内,亚高山-高山草甸群落的Patrick指数、Shannon-Wiener指数、Simpson指数、Pielou指数平均值分别为11、2.15、0.87、0.93. 随着海拔的升高,Patrick指数、Shannon-Wiener指数、Simpson指数均呈显著下降趋势,而Pielou指数变化不显著. 群落TC、TN、TP含量平均值分别为461.19、23.32、1.96 mg/g,C∶N、C∶P和N∶P平均值分别为19.99、242.17、12.10. 与全球尺度和草地生态系统区域尺度的研究相比,该区域草甸群落具有相对稳定的TC含量,以及TN、TP含量高和N∶P低的特点,群落水平下相对较低的N∶P(<14)说明草甸群落植物生长更倾向于受氮元素的限制. 随着海拔升高,群落TC含量、C∶N、C∶P沿海拔梯度均呈显著上升趋势,而群落TN、TP含量均呈显著下降趋势,群落N∶P变化不显著. 在海拔梯度上,群落碳氮磷化学计量特征存在差异性,在一定程度上说明了草甸群落对海拔生境的不同适应策略. 偏冗余分析结果表明,环境因子(海拔和土壤因子)分别解释了亚高山-高山草甸群落多样性和碳氮磷化学计量特征总变化的70.8%和67.8%,海拔因子的解释贡献率大于土壤因子. 研究显示,海拔和土壤因子对五台山亚高山-高山草甸群落多样性和碳氮磷化学计量变化特征存在显著影响,其中海拔因子的影响尤为突出.   相似文献   

11.
The effectiveness and integrity of forest-based emissions reduction schemes such as Clean Development Mechanism Afforestation Reforestation (CDM A R) project and Reducing Emissions from Deforestation and Degradation (REDD+), along with conservation and enhancement of carbon (C) stocks implementation and assessment in developing countries are required not only, the appropriate monitoring and evaluation, rather the precise values of constants being used to estimate the C stocks or C credit in place of default or guess value. Estimates are reported of the C content of wood of four forest species (Shorea robusta, Pinus roxburghii, Tectona grandis and Cinnamomum camphora) and two important farm species (Populus deltoides and Eucalyptus treticornis) in the temperate region of Indian Himalayas, derived using the ash content method. These species were considered keeping in view of their potentiality for the C sequestration and storage projects across the developing countries specifically the South East Asian Countries. The specific gravity, ash content and C proportion is estimated for these six species by selecting random woods pieces. These estimates are designed to improve the calculations of biomass C for use in estimation of C credits in the developing region under CDM A R projects and REDD+ program supported by developed country. Regression analysis of C prediction models revealed that, for all six species, C content may be estimated through specific gravity of the wood by a linear equation without intercept. Indirectly, this results also implies that among the two farm trees, eucalyptus has high potentiality for C capturing and among four forest trees, Shorea robusta has high potentiality, therefore these two should have preference for plantation/regeneration as well as for conservation.  相似文献   

12.
13.
In 1996–1999, different mortality factors of pollen beetle larvae were investigated in twenty six rape fields in the northern part of Switzerland which had either a wild flower strip or an extensively managed meadow adjacent to the long side of the field. At 3 and 30 m into the crop from the conservation strip, total mortality, mortality from predators, parasitoids and unspecified factors were measured. Total pollen beetle larval mortality was 66–96%. Mortality caused by predators was 16–27% and there was no significant difference between mortality at 3 m and that 30 m from the extensively managed meadows. However, in fields with wild flower strips adjacent to them, the percentage mortality from predators was significantly greater at 30 m than at 3 m. The range of parasitism of pollen beetle larvae was 0–54% and was on average greater at 3 m than at 30 m. In fields with wild flower strips, the percentage parasitism with Tersilochus heterocerus was significantly higher than in fields with extensively managed meadows. However, mortality from all parasitoids was only 1–2% and there was no significant difference between 3 and 30 m. The effect of parasitoids on pollen beetle mortality was masked by the high unspecified mortality and the mortality from predators. The unspecified mortality was 46–72% and was significantly greater in 1998 and 1999 than in 1996 and 1997. These differences are probably because of meteorological factors (wet in 1999 and dry in 1998). The possible influences of the two types of conservation strips on pollen beetle larval density were investigated. The results show that in fields with adjacent wild flower strips, the pollen beetle larvae were more evenly distributed (but not significantly so) than in fields with extensively managed meadows where larval density decreases faster from the edge into the rape field.  相似文献   

14.
The objectives of this work are to use gene sequence data to assess the hypothesis that the Lithodinae arose from ancestors with uncalcified abdomens in shallow waters of the North-East Pacific, investigate the monophyly and interrelationships of genera within the Lithodinae and to estimate the scale and minimum number of biogeographic transitions from the shallow environment to the deep sea and vice versa. To do this, phylogenetic analysis from three mitochondrial and three nuclear markers was conducted using minimum evolution, maximum likelihood and Bayesian methods. The Lithodinae as defined to include North Pacific genus Cryptolithodes may be paraphyletic, with the Hapalogastrinae and Cryptolithodes as sister taxa. This implies that the soft-bodied abdomen of the Hapalogastrinae might not be plesiomorphic for the Lithodidae. Paralomis, Lopholithodes, Phyllolithodes, Lithodes and Neolithodes share a common ancestor, from which the North Pacific Hapalogastrinae did not descend. Lithodid ancestors are likely to have had a north Pacific, shallow water distribution and to have had planktotrophic larvae. North Pacific genus Paralithodes is paraphyletic; P. brevipes is the most basal member of the genus (as sampled) while P. camtschaticus and P. platypus are more closely related to the genera Lithodes and Neolithodes. Genera Lithodes, Neolithodes and Paralomis (as sampled) are monophyletic if Glyptolithodes is included within Paralomis. Lopholithodes is closely related to, but not included within, the Paralomis genus. Paralomis is divided into at least two major lineages: one containing South Atlantic, West African, and Indian Ocean species, and the other containing Pacific and South American species. Several species of Paralomis do not resolve consistently with any other groups sampled, implying a complex and possibly rapid global evolution early in the history of the genus. Relationships within the Lithodes genus vary between analytical methods, suggesting that conclusions may not be stable. Consistently, however, Indian Ocean and Pacific forms—L. murrayi, L. longispina and L. nintokuae form a group separated from Atlantic species such as L. santolla, L. confundens, L. maja and L. ferox.  相似文献   

15.
Olfactory stimuli play an important role in the host searching of larval phytophagous insects. Previous studies indicate that larvae that have to find feeding sites after hatching are generally attracted to host volatiles. However, there are few studies on the olfactory responses of neonate larvae to host volatiles in cases when those larvae hatched on the host plant. In the present study, we determined the olfactory responses of neonate larvae of the specialist flea beetle, Altica koreana Ogloblin, to host and six non-host plants, using a static-air "arena." Larvae responded significantly to the host plant Potentilla chinensis Ser. and five of six non-host plants, compared to the control. Larvae did not prefer the host plant over the non-host plants (except Artemisia sp.) when offered a choice. Additionally, odours of a non-host plant, which were unattractive to neonate larvae, may have masked the attractive odour of the host plant. These results indicate that common volatiles can play a major role in attracting larvae of this specialist to plants, but attraction to such odours may not be the major mechanism of host choice.  相似文献   

16.
为有效控制无锡市道路雨水径流面源污染,根据当地径流污染的特点,设计了能去除多种道路径流污染物的复合填料生物渗滤系统,进行污染雨水净化效果的试验研究.结果表明,系统对道路雨水中的悬浮性颗粒物(SS)、耗氧有机污染物(COD)和氮磷污染物均具有明显的去除效果;所有类型的复合填料生物渗滤系统对于SS均具有较高的去除率,能够达到90%以上;以活性炭填料为主的渗滤系统(GAC)对于COD和磷类污染物的去除效果相对较优,以沸石填料为主的渗滤系统(ZFM)对氮类污染物的去除效果相对较优.木屑在系统中的添加能够有效提高系统对氮类污染物的去除率;在系统中混合分散放置木屑的装填方式相较于集中分层的装置方式能够减少木屑溶出物的释放,可使系统达到更高的COD和氮磷污染物的去除效率.  相似文献   

17.
Forests play a fundamental role in the global carbon cycle and can be managed to mitigate greenhouse gas emissions and conserve or sequester carbon. Global policy and environmental changes can affect regional consumption of forest products, as well as inter-regional trade of forest goods and services. This study analyzes global and regional change impacts on the production, consumption and trade of forest products in two Nordic countries, Finland and Sweden. Annual data on removal and trade (1964–2012) for roundwood and sawnwood is used to identify structural breaks based on Chow tests. According to the analysis, the time period is divided into two periods: t1 (1964–1980) and t2 (1981–2012). In the first period, breaks occurred in 1975 and 1976 in the Finnish model and no break is found in the Swedish model. In the second period, we identify breaks in 1991 and 1992 for the Finnish model and in 2004, 2005 and 2006 for the Swedish model. Although our findings have broad empirical support, we do not identify any specific incident as a direct cause of the changes in the consumption and trade patterns of the two types of wood in these countries. The models and analysis presented here can serve as methodological tools for policymakers to better understand the effects of structural changes in the production of forest goods and services in the Nordic region and globally.  相似文献   

18.
Flower colour is an important signal used by flowering plants to attract pollinators. Many anthophilous insects have an innate colour preference that is displayed during their first foraging bouts and which could help them locate their first nectar reward. Nevertheless, learning capabilities allow insects to switch their colour preferences with experience and thus, to track variation in floral nectar availability. Manduca sexta, a crepuscular hawkmoth widely studied as a model system for sensory physiology and behaviour, visits mostly white, night-blooming flowers lacking UV reflectance throughout its range in the Americas. Nevertheless, the spectral sensitivity of the feeding behaviour of naïve moths shows a narrow peak around 450 nm wavelengths, suggesting an innate preference for the colour blue. Under more natural conditions (i.e. broader wavelength reflectance) than in previous studies, we used dual choice experiments with blue- and white-coloured feeders to investigate the innate preference of naïve moths and trained different groups to each colour to evaluate their learning capabilities. We confirmed the innate preference of M. sexta for blue and found that these moths were able to switch colour preferences after training experience. These results unequivocally demonstrate that M. sexta moths innately prefer blue when presented against white flower models and offer novel experimental evidence supporting the hypothesis that learning capabilities could be involved in their foraging preferences, including their widely observed attraction to white flowers in nature.  相似文献   

19.
Livestock [inclusive of ruminant species, namely cattle (Bos Taurus and Bos indicus), sheep (Ovis aries), goats (Capra hircus), and buffaloes (Bubalus bubalis), and non-ruminant species, namely pigs (Sus scrofa domesticus) and chickens (Gallus domesticus)] are both affected by climate change and contribute as much as 14.5 % of global anthropogenic greenhouse gas (GHG) emissions, most of which is from ruminant animals (Gerber et al. 2013). This study aims to estimate the marginal costs of reducing GHG emissions for a selection of practices in the ruminant livestock sector (inclusive of the major ruminant species—cattle, sheep, and goats) globally. It advances on previous assessments by calculating marginal costs rather than commonly reported average costs of abatement and can thus provide insights about abatement responses at different carbon prices. We selected the most promising abatement options based on their effectiveness and feasibility. Improved grazing management and legume sowing are the main practices assessed in grazing systems. The urea (CO(NH2)2) treatment of crop straws is the main practice applied in mixed crop–livestock systems, while the feeding of dietary lipids and nitrates are confined to more intensive production systems. These practices were estimated to reduce emissions by up to 379 metric megatons of carbon dioxide (CO2) equivalent emissions per year (MtCO2-eq yr?1). Two thirds of this reduction was estimated to be possible at a carbon price of 20 US dollars per metric ton of CO2 equivalent emissions ($20 tCO2-eq?1). This study also provides strategic guidance as to where abatement efforts could be most cost effectively targeted. For example, improved grazing management was particularly cost effective in Latin America and Sub-Saharan Africa, while legume sowing appeared to work best in Western Europe and Latin America.  相似文献   

20.
Latent period, burst time, and burst size, kinetic parameters of phage infection characteristic of a given phage/host system, have been measured for a wide variety of lactic acid bacteria. However, most studies to date were conducted in optimal growth conditions of host bacteria and did not consider variations due to changes in external factors. In this work, we determined the effect of temperature, pH, and starvation on kinetic parameters of phages infecting Lactobacillus paracasei, Lactobacillus plantarum, and Leuconostoc mesenteroides. For kinetics assessment, one-step growth curves were carried out in MRS broth at optimal conditions (control), lower temperature, pH 6.0 and 5.0 (MRS6 and MRS5, respectively), or in medium lacking carbon (MRSN) or nitrogen (MRSC) sources. Phage infection was progressively impaired as environmental conditions were modified from optimal. At lower temperature or pH, infection was delayed, as perceived by longer latent and burst times. Burst size, however, was lower, equal or higher than for controls, but this effect was highly dependent on the particular phage–host system studied. Phage infection was strongly inhibited in MRSC, but only mildly impaired in MRSN. Nevertheless, growth of all the bacterial strains tested was severely compromised by starvation, without significant differences between MRSC and MRSN, indicating that nitrogen compounds are specifically required for a successful phage infection, beyond their influence on bacterial growth.  相似文献   

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