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1.
Bark beetles (Coleoptera: Curculionidae, Scolytinae) are commonly recognised as important agents of tree mortality in coniferous forests of the Western Carpathians. They, together with weevils, are consistently associated with ophiostomatoid fungi. Information regarding conifer beetle-associated fungi in the Western Carpathians remains incomplete and unreliable, particularly with respect to fir-infesting bark beetles. This study aims to clarify associations between fungi in the genera Graphilbum, Leptographium, Ophiostoma and Sporothrix (Ophiostomatales) and their beetle vectors in Norway spruce (Picea abies), European larch (Larix decidua) and silver fir (Abies alba). Samples associated with 20 bark beetle species and weevils were collected from nine stands in Poland and the Czech Republic. Fungi were isolated from adult beetles and galleries. Isolates were identified based on morphology, DNA sequence comparisons for four gene regions (ITS, LSU, ß-tubulin, TEF 1-α) and phylogenetic analyses. In total, 46 distinct taxa were identified, including 25 known and 21 currently unknown species. Several associations between fungi and subcortical insects were recorded for the first time. In addition, O. borealis and O. quercus were detected from A. alba for the first time. The composition of the fungal communities varied among the studied tree species and to a lesser degree among the beetle species. The spruce-infesting bark beetles were commonly associated with species of Leptographium s. l. and Ophiostoma s. str.; the larch-infesting bark beetles were often associated with Ophiostoma s. str. and Sporothrix, while the fir-infesting bark beetles were commonly associated with Ophiostoma s. str. and Graphilbum. The most commonly encountered fungal associates of the examined insects were (a) Grosmannia cucullata, G. piceiperda, Grosmannia sp. 1, Ophiostoma macroclavatum and O. piceae with the spruce-infesting bark beetles; (b) O. pseudocatenulatum and Sporothrix sp. 1 with the larch-infesting bark beetles; and (c) O. piceae, Ophiostoma sp. 2 and Graphilbum sp. 2 with the fir-infesting bark beetles. The differences in fungal associates among the bark beetle species occurring on P. abies, L. decidua and A. alba could be linked to the different habitats that these beetles occupy.  相似文献   

2.
Pathogen occurrence was studied in 16?099 adult specimens of 10 different bark beetle species, which live associated on Norway spruce (Picea abies (L.) Karst.). Beetles (mainly Ips typographus L. and Pityogenes chalcographus L.) were collected from 6 different localities in Austria (4 secondary spruce stands and 2 natural forest type stands, 9 sampling plots in total) in elevations between 400?m and 1600?m. Various viral, protozoan, and fungal pathogens could be diagnosed with a light microscope in the examined beetles. Numerous pathogen species were known from former studies, some pathogens were totally new or could be found in a new host species beside their type host. The most dominant pathogen species were Protozoa, Gregarina cf. typographi, Malamoeba cf. scolyti, and Chytridiopsis cf. typographi. Over the whole investigation period, the highest pathogen diversity with eight pathogen species was found in I. typographus. Differences were observed in the pathogen complex of each beetle species from the different collection sites and in different years of investigation. Several species showed an overlapping in their host range and infected various bark beetle species. Furthermore, pathogen occurrence and prevalence differed in bark beetles from 4 different sampling plots in an area (one locality) within a distance of a few kilometres.  相似文献   

3.
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   

4.
Elm (Ulmus, Ulmaceae) is one of the most popular and important trees in urban and landscape areas in Iran. A severe decline of elm trees has recently been observed in some areas of Kerman and Shiraz cities. However, the identity of the causal agents has not yet been investigated. The purpose of this study, carried out in the years 2012–2014, was to isolate and identify fungal trunk pathogens associated with decline symptoms observed in elm trees. Samples were collected from trunks and branches of trees showing various disease symptoms and internal wood lesions. Fungal isolations were made from discolored or decayed wood tissue. In Kerman some elm trees were attacked by the beetle Aeolesthes sarta; therefore, samples were also collected from larvae and adults of beetles associated with trees showing wood damage. Fungal isolates were identified by morphological, cultural and molecular characteristics. Thirteen fungal species, Phaeoacremonium (P.) minimum, P. parasiticum, P. sicilianum, P. alvesii, P. fraxinopennsylvanicum, Spencermartinsia viticola, Dothiorella (Do.) sarmentorum, Neoscytalidium hyalinum, Diatrype (Di.) whitmanensis, Cosmospora viridescens, Phoma (Pho.) herbarum, Phellinus (Phe.) tuberculosus and Inonotus levis were identified. Phaeoacremonium parasiticum was the only species isolated from both larvae and adult beetles. Pathogenicity trials were performed on detached shoots of elm under greenhouse conditions. Dothiorella sarmentorum was the most virulent species based on the length of wood necrosis. This study is the first report of P. sicilianum, C. viridescens and Phe. tuberculosus in Iran. In addition, most of the isolated species are reported for the first time on elm trees in the world.  相似文献   

5.
Ecological investigation of the distribution and composition of dung beetle species utilizing feces of wild mammals has rarely been attempted, especially in cool-temperate forests. In this study we recorded and evaluated the community structure of dung beetle species utilizing feces of Japanese monkeys (Macaca fuscata) by conducting a macro-scale inventory survey in the northeastern Shirakami Mountains, located in the northernmost part of mainland Japan. Moreover, to assess the effect of human-induced forest disturbance on species assemblages in this cool-temperate area, we also carried out field sampling using pitfall traps baited with monkey feces in primary forests, secondary forests, and coniferous plantations, during every season except winter. Our findings were: (1) 14 dung beetle species comprising eight dwellers and six tunnelers utilized monkey feces; (2) Aphodius eccoptus was the core species in dung beetle assemblages attracted to the feces during spring and summer; (3) the frequency of occurrence of every species was extremely high in spring; and (4) human-induced forest disturbance did not increase species richness or biomass in cool-temperate forests.  相似文献   

6.
Spatial and temporal aspects of flight activity of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), were investigated in a grain-growing district in southern New South Wales, Australia. This species is now considered an important economic pest in Australia due to the development of a high level of resistance to phosphine. Flight activity was monitored at 4-weekly intervals near and away from grain silos. We present data for the first time from trapping with a commercial aggregation pheromone lure (active trapping phase), as well as data on C. ferrugineus by-catch from trapping using an aggregation pheromone lure for another species (passive trapping phase). There was a strong seasonal pattern to flight activity, with no flight detected during the winter months of June, July, or August. This appears to be primarily related to ambient temperature, with maximum temperatures above 20 °C initiating flight. Beetles were trapped both near and away from grain storages, demonstrating flight dispersal in the farm environment. The results of this study in southern New South Wales also show that C. ferrugineus beetles of both sexes are flying in the farm environment. During the passive trapping phase, the sex ratio of trapped beetles did not deviate from 1:1, but during active trapping, the sex ratio was biased to females (3:1). While more work is required, information garnered from this study provides a basis for management strategies for the control of C. ferrugineus in south-eastern Australia.  相似文献   

7.
There is growing evidence that insects rely on chemical cues to locate food, hosts, predators, and potential mates. The pulse beetle Callosobruchus maculatus has been recognized for decades as the major post-harvest insect pest of legume seeds. In a previous study, we identified five volatile organic compounds in the headspace of dried green pea seeds as electroantennographically active in C. maculatus antennae: 1-pentanol, 1-octen-3-ol, (E)-2-octenal, nonanal, and 3-carene. Some of these compounds used individually elicited attraction toward C. maculatus adults. However, since volatile compounds are generally perceived by insects as blends, we hypothesized that C. maculatus might particularly show attraction to different mixtures of the aforementioned compounds. To test this, we examined the behavioral response of C. maculatus toward a quinary, a quaternary, two ternary, and three binary mixtures in a dual choice Y-tube olfactometer. The results seem to indicate that in a dual choice situation, the first choice made by the beetles is an indication of the attractive or repellent properties of the mixture tested. In most cases, a positive response of C. maculatus to the mixtures of volatiles was observed. Females were attracted to five mixtures, while males were attracted only to two binary mixtures consisting exclusively of aldehydes. The other mixtures caused C. maculatus to respond negatively, suggesting they were repellent. Further investigations with the attractive mixtures should be done in real storage conditions with the aim of developing a trap for the pulse beetle, C. maculatus.  相似文献   

8.
Snow/wind damage is one of the important natural disturbances in forest ecosystems, especially in a montane secondary forest. However, the effects of snow/wind damage remain unclear which affects the management of these forests. Therefore, we investigated the responses of species, individual tree traits and stand structure to snow/wind damage in a montane secondary forest. Results show that, amongst the canopy trees, Betula costata exhibited the most uprooting, bending and overall damage ratio (the number of damaged stems to the total number of stems in a plot); Quercus mongolica showed the highest breakage ratio and Fraxinus mandshurica and Juglans mandshurica the least overall damage ratios. Among the subcanopy trees, Carpinus cordata, Acer mono, Acer tegmentosum and Acer pseudo-sieboldianum showed the least uprooting and breakage, and the most bending damage. A. pseudo-sieboldianum demonstrated the lowest breakage and highest bending damage ratios. These findings indicate that different species have various sensitivities to snow/wind damage. Larger trees (taller, wider crowns) tend to break and become uprooted, while smaller trees are bent or remain undamaged, suggesting that tree characteristics significantly influence the types of damage from snow and wind. Stands of Q. mongolica and B. costata had the highest damage ratios, whereas A. pseudo-sieboldianum had the lowest snapping ratio. In summary, the severity and type of snow/wind damage are related to individual tree attributes and stand-level characteristics. Therefore, selection of suitable species (e.g., shorter, smaller with deep root systems, hard wood, bending resistance and compression resistance) and appropriate thinning are recommended for planting in the montane secondary forests.  相似文献   

9.
Tobacco beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae), is one of the most serious insect pests of stored tobacco, and traps baited with the female-produced sex pheromone, serricornin, are used for monitoring the pest. In two trapping experiments carried out in tobacco warehouses in Greece, two commercially available trap and lure systems for L. serricorne were found to be equally effective in terms of the numbers of beetles trapped. In contrast to previous reports, anhydroserricornin was unattractive and lures containing serricornin and anhydroserricornin were less attractive than lures containing serricornin only. The sex pheromone of the other main insect pest of tobacco, Ephestia elutella (Hübner) (Lepidoptera: Pyralidae), could be added to the lures without affecting the attractiveness of either pheromone to their respective species. Lures remained attractive for at least 4 weeks under field conditions, and, in laboratory tests, release of pheromone could still be detected after 30 days at 27 °C. The stereoisomeric composition of the serricornin in the two commercial lures was similar with high proportions of the attractive (4S,6S,7S)-isomer. The proportion of the (4S,6S,7R)-isomer was low, and this is known to reduce the attractiveness.  相似文献   

10.
New measures for effective monitoring and controlling of bark beetle infestations are needed as a response to intensified outbreaks caused by the climate change. Various environmental factors affect tree health and susceptibility, as well as stand predisposition to bark beetles. European spruce bark beetle Ips typographus L. abundance and outbreak frequency in Finland has significantly increased during the last decade. The ability to identify sites under a high risk of infestation would facilitate adaptation to this new situation and help target limited forest health management resources. Accordingly, our goal was to investigate the importance of various stand, soil and topographic characteristics in the assessing predisposition of Norway spruce dominated urban forest in southern Finland to I. typographus infestations. Information on the environmental factors was assessed in the field in 2014 and derived from a digital elevation model. Ips typographus infestation intensity was classified into three infestation index classes based on tree-wise symptoms of resin flow, discoloration and defoliation. Cumulative logit link models were utilized for investigating stand-level infestation probability. The best explanatory factors were aspect, slope, site type and soil texture. Models with the highest cumulative probabilities for severe infestation were linked with eastern aspect, moderate steep slope and rich site type fertility (0.72) and eastern aspect, shallow soil and rich site type fertility (0.71). Higher soil C/N ratios with east aspect and rich site type fertility was associated with an increased risk of severe infestation in a third model. The lowest risk was associated with southern and southwestern aspects, fine soil texture, moderate site fertility and gentle slopes.  相似文献   

11.
Niche conservatism providing support for using ecological niche modeling in biological invasions has been widely noticed; nonetheless, the impacts of human disturbance on niche changes and model predictions are not fully recognized. In this study, climate niche changes during the invasion of Japanese beetle (Popillia japonica) were studied under the framework of niche unfilling, stability, and expansion situations. The beetle might undergo niche expansion because of the small native range (Japan) relative to the broad invade range (North America). Relative roles of climatic and anthropogenic factors and their interactions in determining the spread of P. japonica were investigated. Results suggest that the climate niche was conserved during P. japonica invasion, climate niche unfilling rather than niche expansion was observed, suggesting there are suitable climate space remain unoccupied. Inclusion of anthropogenic factors into climate niche model has improved niche model prediction values in areas of high human activity. During P. japonica invasion, anthropogenic factors influenced the climate niche expression and altered the effect of climate suitability. In areas of poor or unsuitable climate, the human activities facilitated the establishment of P. japonica and functioned synergistically, whereas in highly suitable areas, including anthropogenic variables decreased climate suitability. These findings are pivotal to our understanding of climate niche conservatism and niche model transferability when predicting areas of invasion of P. japonica and can be applied elsewhere for predicting other pest’s invasion potential.  相似文献   

12.
Aromatic spice crops such as coriander, Coriandrum sativum L., and fennel, Foeniculum vulgare L., are among the major seeds exported to the international market. Observations on the stores of these crops revealed differences in their susceptibility to the cigarette beetle, Lasioderma serricorne (F.) (Col., Anobiidae). Coriander seeds proved to be the most appropriate diet for the beetle. The population dynamics of L. serricorne (F.) was determined, showing 3 generations during the period from May to October.  相似文献   

13.
The temporal phenology of leaf bud bursting, leaf initiation, leaf maturation, leaf fall, flower initiation, fruit initiation and fruit fall was recorded for eight tree species (Ficus hispida, F. squamosa, Mallotus nudiflorus, M. philippensis, Shorea robusta, Schleichera oleosa, Pongamia pinnata and Terminalia arjuna) in the tropical moist deciduous forest of Himalayan Terai region from November 2009 to October 2012. The study revealed that a short low temperature dry period, sufficient winter rain and temperature rise are the triggering factors for summer leaf flushing and, the increased soil water availability for second leaf flushing in rains. Initiation of flowering with leaf emergence in the dry period supports higher rate of fruit setting due to maximum availability and activities of pollinators. The dispersal and post dispersal success of fruits increased by their ripening before and/or in the rainy season. In T. arjuna, no correlation has been found between the fruiting and rains. M. nudiflorus and M. philippensis initiate leaves and flowers with the first significant increase in temperature and photoperiod and are thus suggested as the potential tree species for climate change studies in tropics.  相似文献   

14.
Thiamethoxam (ACTARA® 25WG) was evaluated for its insecticidal activities against the bamboo powder post beetle Dinoderus minutus Fabricius (Coleoptera: Bostrichidae). The study showed that thiamethoxam had contact toxicity against D. minutus. Based on dose-mortality responses, LC50 values for thiamethoxam against D. minutus ranged from 1.74 to 7.94 μg ml?1. Laboratory and field exposure tests showed that thiamethoxam at concentration of atleast 10 μg ml?1 may have anti-oviposition or anti-feeding effects on D. minutus and can protect post harvest Bambusa vulgaris Schrad. culms against the infestation of this bamboo boring beetle.  相似文献   

15.
Ancient Egyptian insect relics were accidentally enclosed in embalming resin which leaked from a priest's mummy and solidified on the floor of a wooden coffin from the end of the XVIIIth Dynasty (presumably 1323?–?1295 BC). The preserved insect relics were blowflies (Calliphoridae) recognized as Chrysomya marginalis or Chrysomya megacephala whose larvae had developed by feeding on the deceased's body prior to mummification as well as furniture beetles (Anobiidae) being either Oligomerus ptilinoides or Priobium carpini whose larvae had ingested the coniferous wood of the coffin. It is most likely that the human corpse and coffin were first attacked by the blowflies and furniture beetles prior to embalming, while infestation of the insect remains and textiles by Anthrenus sp. (Dermestidae) occurred in our time.  相似文献   

16.
The Asian spotted wing drosophila, Drosophila suzukii, has recently become a serious pest of soft fruits in Europe. Classical biological control through the introduction of larval parasitoids from its native range in Asia is presently being considered. However, host specificity of potential biological control agents has to be determined to avoid releasing species that may have unintended non-target impacts. Larvae of six different European non-target fly species and the target D. suzukii were exposed either on diet or blueberries to three Asian larval parasitoids, Asobara japonica, Leptopilina japonica, and Ganaspis cf. brasiliensis, and one European species, Leptopilina heterotoma. Asobara japonica showed the lowest specificity, attacking and developing in all Drosophilidae. Leptopilina japonica successfully parasitized two non-target Drosophilidae, D. melanogaster and D. subobscura, with one singly progeny emerging from D. immigrans. Ganaspis cf. brasiliensis had the highest level of specificity but variations occurred between two geographical populations tested. A Japanese population was strictly specific to D. suzukii, whereas another population from China parasitized D. suzukii, D. melanogaster and sporadically D. subobscura. The European L. heterotoma successfully developed in D. melanogaster, D. subobscura and occasionally in D. immigrans, but nearly all eggs and larvae in D. suzukii were encapsulated. These results show that Ganaspis cf. brasiliensis is the species with the highest potential for biological control, but more studies are needed on its taxonomic status and the existence of biotypes or cryptic species varying in their specificity before field releases can be conducted in Europe.  相似文献   

17.
There are many published studies of either insect growth regulators (IGR) or chitinase inhibitors applied directly to larvae of stored product insects or incorporated into their diets, but few studies evaluating efficacy of IGRs or chitinase inhibitors applied alone or in combination with a surface for residual control. Tests were conducted to evaluate susceptibility of Tribolium castaneum (Herbst), the red flour beetle, Trogoderma variabile (Ballion), the warehouse beetle, and Dermestes maculatus (DeGeer), the hide beetle, to Tekko® Pro which contained the IGR pyriproxyfen and the chitinase inhibitor novaluron as active ingredients. Efficacy was assessed by adult emergence of exposed immatures, an index based on development of those exposed immatures, and progeny production of exposed adults. Concrete arenas were treated with the label rate of the insecticide applied to a surface, and bioassays were conducted at 0–16 weeks post-treatment. No exposed T. castaneum eggs or larvae reached the adult stage and index values for exposed eggs and larvae remained near the minimum. Adult emergence of T. variable from eggs or larvae did not exceed 25% for the first 8 weeks of the test, but at the end of the test at 16 weeks adult emergence was 44 and 71%, respectively, for eggs and larvae. No eggs or larvae of D. maculatus emerged as adults, but excessive cannibalization in untreated controls occurred throughout the test. Results show that Tekko® Pro will give residual control of T. castaneum and T. variabile, and could replace older conventional neurotoxic insecticides for management of stored product insects.  相似文献   

18.
The natural resistance of Erythrophleum fordii Oliver wood to degradation by Phanerochaete sordida and Phanerochaete chrysosporium white-rot fungi was investigated. In this study, Fagus crenata Blume (Japanese beech) was selected as reference species. The results showed that both fungi caused less than 2% mass loss in E. fordii wood, while the degradation of beech wood produced by P. chrysosporium and P. sordida was approximately 12 and 14%, respectively. Microscopic observations revealed high structural rigidity of E. fordii timber. Hyphae were only observed in the lumen of vessels and parenchymal cells, while the fibers were not affected. The E. fordii wood fiber consisted of highly lignified thick-walled fibers with the fiber lumina almost completely closed. Two-dimensional heteronuclear single-quantum coherence nuclear magnetic resonance evaluation revealed the E. fordii wood to have a highly condensed-lignin structure that reflected by the durability classes. These unique parameters are likely to be critical for the high natural resistance of E. fordii.  相似文献   

19.
Lateralization (i.e. left–right asymmetries in the brain and behaviour) has been documented in all vertebrate classes, while evidences for invertebrates are limited. To the best of our knowledge, there is no information about behavioural asymmetries in the order Coleoptera. In this research, we investigated the lateralization of mating traits in two major pests of stored products: the rice weevil, Sitophilus oryzae (Coleoptera: Curculionidae), and the confused flour beetle, Tribolium confusum (Coleoptera: Tenebrionidae). Both T. confusum and S. oryzae males showed population-level left-biased copulation approaches of potential mates. Interestingly, T. confusum and S. oryzae males performing left-biased copulation attempts achieved higher mating success over right-biased males. Furthermore, S. oryzae males periodically exhibited a typical head wagging behaviour, which consists of waving the rostrum laterally across the female thorax and then resting the rostrum on the mid thorax. This behaviour was right-biased, even in the majority of males that previously showed left-biased copulation attempts. The quantification of mating displays could allow comparisons with other strains, in order to evaluate the impact of a given host or of the rearing methods on the mating traits of S. oryzae and T. confusum. Overall, this is the first report of lateralization of mating traits in Coleoptera. Furthermore, this research adds basic knowledge to the reproductive behaviour of S. oryzae and T. confusum.  相似文献   

20.
Canningia tomici sp. n. (Microsporidia, Unikaryonidae) infects the midgut epithelium, the gut muscules, Malpighian tubules, connective tissues, adipose tissues and the gonads of the pine shoot beetle, Tomicus piniperda (L.) (Coleoptera, Scolytidae). The infection is present in populations of Tomicus piniperda in Europe and in the United States. Uninucleate oval single spores occur in two sizes: 2.8?±?0.4?× 1.4?±?0.4?μm and 3.8?±?0.3?×?2.0?±?0.2?μm. The polar filament of this microsporidium is fixed subapically in a flat anchoring disc. The thick posterior lamellae of the binary polaroplast are asymmetric due to the lateral fixation of the polar filament.  相似文献   

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