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1.
The Palaearctic leaf beetle Chrysomela lapponica usually feeds upon willows in the northern region of its occurrence. However, in Central Europe, some populations are known that have specialised on birch. In this study, we investigated the significance of other herbivores occurring together on the same host plants as possible exploitative competitors of C. lapponica. Two populations were studied: a population from Finland specialised on the willow Salix borealis, and a population from the Czech Republic, specialised on the birch Betula pubescens. Abundances of folivorous and suctivorous insects on both host plants were recorded at both population sites. The willow leaf beetle Phratora vitellinae was the most abundant herbivorous insect at both study sites on willow. A field study was conducted to examine the effects of P. vitellinae on the performance of C. lapponica. The presence of P. vitellinae larvae on the same twig upon which C. lapponica larvae were feeding did not affect increase of body weight in C. lapponica larvae. Thus, the high resource availability of both willows and birches suggest that interspecific competition is unlikely to be a selection factor driving the evolution of host shift in C. lapponica.  相似文献   

2.
Larssoniella duplicati n.sp. infects the midgut muscularis, the Malpighian tubules, and the ovaries of adult Ips duplicatus (Sahlb.) in the Czech Republic. The microsporidian attacks up to 50% of the population. Oval spores of two sizes, 3–3.5×1.5–2 and 2–2.5×1.5 μm have the polar filament coiled in 6/7 coils, representing primary and environmental spores, respectively. In early sporogony the young spores produce long electron dense threads and tubules of secretions, which remain fixed around the spore and avoid their free release during dissection of infected hosts. The microsporidian was not found in associated bark beetles such as Ips typographus (L.), or I. amitinus (Eichh.) and others.  相似文献   

3.
The Czech Republic is passing the third outbreakperiod ofIps typographus since 1880. The first and second outbreaks (1870–1876 and 1945–1954) were a consequence of falling of masses of trees caused by storm. The data ofIps duplicatus during the first outbreak mentioned in later papers are a mistake, reality it has beenIps amitinus.The third outbreak from 1980 until now has not one but several from man dependent and not dependent causes. There are: Falling of trees, by repeating windstorms damage of trees by pollutions of SO2 and their pollutants, the increasing temperatures during the last period of 30 years and the development of higher numbers of generations of the beetle. The successes in using pheromones in control ofIps typographus were overestimated. Also the changes in the ownership of forest stands were of importance. Ips duplicatus occured in North Moravia having been migrated across Northpoland to the east Czech Republic.In the Nationalpark of umava (on the other side to the Nationalpark of Bavaria) in some reservations no measures againstIps typographus as in Bavaria were made. Here new control measures must be taken against this pest.  相似文献   

4.
Wu Gang  Li Junqing 《林业研究》1998,9(4):290-291
The distribution, regeneration and succession ofFagus in China were systematically analyzed in comparison with those in Europe and in northern America. The results showed that it was very likely that China was the distribution center ofFagus, which originated in eastern Asia, migrated into northern America and then into Europe. Distribution ofFagus in China is relatively independent with seven species. The main reason for wide distribution ofFagus in Europe, but unitary species, is possibly the influence of the climate in Quaternary Period, and also related with influence of the ocean climate. This study was supported by National Natural Sciences Foundation of China (39500116 and 39670145) (Responsible Editor: Chai Ruihai)  相似文献   

5.
A part of the territory of the Czech Republic represents the up-dated northern limit of distribution (status 1997) which the Russian wheat aphid (=RWA),Diuraphis noxia (Kurdj.) has reached during its expansion from the southeast to central Europe. The newly defined area is classified as one of the adventive routes which may be derived from the main expansion of RWA from its native home (central-western Asia) into the broader Mediterranean area. Distribution and its history, and ecology (life-cycle, host plants, seasonal history, both native and introduced natural enemies) of RWA are presented on ground of field evidence and trials obtained in 1995–1997 in the Czech Republic. The origin of RWA, its distribution and establishment in the target area, as well as prognosis of its further expansion, are reviewed and discussed. Steps and approaches to RWA detection in the crop, as well as some notes on its management, are added.  相似文献   

6.
We tested the effects of forest management type (managed vs. unmanaged) on the abundances of Ips typographus (L.) (Col., Curculionidae, Scolytinae) and related parasitoids and predators reared from spruce bolts exposed in Białowieża, Poland. Habitat availability for these species differed between forest types mainly as a result of regular sanitary fellings occurring in managed forests. Populations of the common polyphagous insect predators Paromalus paralellepipedus (Herbst) and Plegaderus vulneratus (Panz.) (Col., Histeridae) or parasitoids Rhopalicus tutela (Walk.), Dinotiscus eupterus (Walk.) and Roptrocerus xylophagorum Ratz. (Hym., Pteromalidae) related to I. typographus did not differ between managed and unmanaged forests. Only Thanasimus spp. (Col., Cleridae) was significantly more abundant in managed forest, possibly because it was favored by the more open, sunny stands. However, the experiment was performed in stands where spruce is only a minor component and during the non-epidemic phase of the bark beetle population, so further experiments may be necessary to determine if the effects of sanitary fellings are greater in different forest types and at different stages of the population cycle.  相似文献   

7.
Until recently, the pine sawyer Monochamus galloprovincialis (Olivier) (Coleoptera; Cerambycidae) was considered a secondary forest pest in Portugal. Its pest status changed when it was found to be the main vector of the recently introduced pine wood nematode (PWN) Bursaphelenchus xylophilus (Steiner and Bührer) Nickle (Nematoda; Aphelenchoididae). A survey in three locations within the PWN-affected zone was conducted in order to identify parasitoids associated with immature stages of the beetle and to evaluate their importance. No parasitoid was found associated with the insect eggs whereas 10% of the larvae were found parasitised by three Braconidae. Cyanopterus flavator Fabricius was the most numerous species; Iphiaulax impostor (Scopoli) and Coeloides sordidator Ratzeburg were the other species present. A review of the parasitoids associated with Monochamus in Europe, eastern Asia and North America was made, and the possibility of using the local species in future biological control programmes in Portugal is briefly discussed.  相似文献   

8.
Parasitic Hymenoptera from the suprafamily Ichneumonoidea attacking the horse chestnut leafminer Cameraria ohridella Deschka & Dimic (Lepidoptera: Gracillariidae) were studied in southwest Slovakia during 2000 and 2001. The search for such species resulted in the determination of eight ichneumonid species, Gelis agilis (Fabricius), Itoplectis alternans (Gravenhorst), I. clavicornis (Thompson), I. maculator (Fabricius), Scambus annulatus (Kiss), S. brevicornis (Gravenhorst), Zatypota percontatoria (Müller), Adelognathus sp. and a braconid Colastes braconius Haliday. The most abundant species was S. annulatus. All these species recorded are polyphagous and often facultative hyperparasitoids, except C. braconius, which departs from this norm in not being hyperparasitic. The presence of more diversified native parasitoids and hyperparasitoids from the Ichneumonoidea predicate a slow successive adaptation of the parasitoid fauna to the invasive host, Cameraria ohridella.  相似文献   

9.
In this study, the pathogen and parasite spectra of Turkish populations of the great spruce bark beetle Dendroctonus micans (Kugelann) (Coleoptera: Curculionidae, Scolytinae) are analysed. In addition to the previously studied infective green alga Helicosporidium, three more pathogens and parasites, i.e. the yeast Metschnikowia sp., the neogregarine Mattesia sp. and a nematode, were recorded here for the first time. The pathogens and parasites occur in different quantities and combinations in outbreaks of the beetle at five Turkish localities.  相似文献   

10.
A number of various species of blue-stain fungi were isolated fromTomicus piniperda adults at various stages of development, as well as from the galleries, pupal chambers and sapwood underneath galleries on Japanese red pine. This study was an attempt to identify the species, composition of blue-stain fungi associated withT. piniperda, the frequency of occurrence of the fungi, and their role in the sapwood-staining of Japanese red pine in Tsukuba City, central Japan. Among the seven species of blue-stain fungi isolated, an undescribed species ofOphiostoma together withO. minus were the dominant species and closely associated withT. piniperda. These two species occurred on newly emerging adults more frequently than the overwintered adults.Hormonema dematioides was also associated with the beetle, however, its frequency of occurrence from the emerged new adults was very low. Although the two other species,O. ips andGraphium sp. were also isolated from emerged beetles, the frequency of these fungi from gallery systems suggested that they were accidentally carried byT. piniperda. Leptographium wingfieldii, known to be associated with the beetle in Europe, was also isolated at a very low frequency and the fungus seemed not to be closely associated with the beetle.Ophiostoma sp. andO. minus appear to be the most important causes of blue-stain of Japanese red pine sapwood after infestation byT. piniperda.  相似文献   

11.
Bursaphelenchus mucronatus Mamiya et Enda has been recovered for the first time from adults of the cerambycid beetle, Monochamus urussovi (Fischer), in Hokkaido, Japan. The nematode was also recovered from the inner bark of Picea jezoensis (Siebold et Zuccarini) Carrière and Abies sachalinensis (Fr Schmidt) Masters infested with M. urussovi larvae. PCR–RFLP analysis indicated that B. mucronatus in Hokkaido is the European type.  相似文献   

12.
The period between 2000 and 2002 repeated outbreaks of the web spinning sawfly Cephalcia lariciphila (Wachtl 1898) around the village of Větrny Jeníkov, Czech Republic. The impact of defoliation, caused by C. lariciphila feeding, on tree-ring formation of European larch (Larix decidua Mill.) was studied using dendrochronological methods. Heavy defoliation resulted in much less growth in the years of insect attack, the average incremental loss being 67% for the 2000–2002 period. Also, defoliation resulted in the formation of latewood with fewer cells and reduced cell-wall thickness.  相似文献   

13.
Forests that encompass the border triangle of Poland, the Czech Republic and Slovakia currently suffer from centuries of inadequate forest management strategies, including overexploitation during the countries’ respective communist regimes and high stress levels due to airborne emissions from heavy industry. Since the fall of the Iron Curtain, each country has approached forest monitoring, protection and the improvement of forest conditions in its own way. Spaceborne remote sensing of forest changes across country borders offers great potential for better understanding the underlying drivers of change and for developing comparable indicators between countries.  相似文献   

14.
During research conducted in northern Italy for the State Forestry Service LIFE Nature project, a single male specimen of the scolytine ambrosia beetle Monarthrum mali (Fitch) was collected in an ethanol-baited window flight trap. Trapping started in 2005, but the species was first collected in August 2007, suggesting that the establishment of M. mali in northern Italy is very recent. Monarthrum mali represents the second North American ambrosia beetle to be introduced to Europe, and joins Phloeotribus limnaris and Xylosandrus crassiusculus as recent scolytine introductions to Europe via Italy that pose potential threats to Europe’s nurseries, orchards and plantations.  相似文献   

15.
The population structure of Hymenoscyphus fraxineus, the causal agent of ash dieback, was assessed at four closely located sites in the Czech Republic. To analyse the genetic variation, one Swiss and one Norwegian population with known population structures were selected as reference points. The analysis was performed using 16 previously published and five newly developed microsatellite markers. The quality of the new markers was assessed by sequencing the flanking region, identifying the type of the mutation and analysing the inheritance and linkage between all pairs of loci. In addition, markers were tested on 45 Japanese strains to confirm their usability on native H. fraxineus populations in Asia. One of the new markers was monomorphic in all European populations and one marker exhibited a high percentage of null alleles in the Japanese samples. Twenty markers in the four Czech populations showed lower average gene diversity than in the other two European populations. One Czech population significantly differed from all the others, with a pairwise GST of approximately 0.2, the lowest allelic richness and very low average gene diversity, likely resulting from a founder effect. The amount of genetic differentiation between the four neighbouring Czech populations exceeds the expected value from previous Europe‐wide population studies and suggests that local population dynamics can affect the population structure of H. fraxineus.  相似文献   

16.
The dynamics of a recent outbreak of the spruce bark beetle (Ips typographus) in Switzerland was ruled by a devastating winter storm in 1999 and the drought and heat of the summer 2003. Starting from a similar level of population sizes, estimated as the rate of infested growing stock, beetle populations increased differently in magnitude and time among different regions in Switzerland. Accordingly, we expected local or regional genetic differentiation as a result of such repeated population expansion/breakdown dynamics. We analyzed 5 nuclear microsatellites of spruce bark beetles sampled from pheromone traps at 30 locations distributed over Switzerland. Our genetic results did not indicate any sign of population differentiation, structure, isolation by distance, or recent bottlenecks. This complete lack of genetic structure suggests that spruce bark beetles are highly mobile, precluding the formation of a spatial structure at neutral molecular markers. Thus, this molecular–genetic approach does not allow us to discriminate among regional gene pools and to identify the origin of expanding beetle populations.  相似文献   

17.
An ongoing expansion of Myzocallis (L.) walshii (Monell) in the NE Iberian Peninsula was detected. The aphid species was recorded in Catalonia, Andorra and Navarra. Adaptation of local native parasitoids (at least Trioxys pallidus Haliday and T. tenuicaudus Stary) to the new immigrant was documented, together with background information on their host range in the native environments. The detection of parasitoids of M. walshii is the first published evidence in Europe. The new evidence for M. walshii in the NE Iberian Peninsula also supports the warning of the expansion of the aphid as a pest of Quercus rubra over Europe.  相似文献   

18.
A poorly known chrysomelid beetle, Chrysolina fastuosa (Scopoli) has been found in a strikingly great number on black horehound (Ballota nigra L.), a soft caulescent plant belonging to the Lamiaceae family. B. nigra can be found from April to August commonly on roadsides, along walls or at the border of gardens and orchards in Hungary and continental Europe. It can be called a minor weed. The glistering tiny adults that feed voraciously on leaves cause apparently significant damage. The subsequent investigation, which focuses on the number of feeding individuals and the loss of plant tissue, showed 1–24 beetles on a plant and the consumed leave surface which amounted to 8–94%. The repeated damage assessment, a week later showed a significantly unimportant increase in the number of individuals but a significant 20–31% increase in the plant surface loss. According to the literature, Ch. fastuosa has been found in association with other Labiatae plants such as Galeopsis pubescens Besser, Lamium album L. and Urtica dioica L. (Urticaceae). Thus, considering its efficiency mentioned above, it could be used to augment and maintain its populations as a biological control agent for these weeds. However, taking into consideration the growing importance of the production of medicinal plants among which Lamiaceae species are numerous, Ch. fastuosa can cause damage that cannot be neglected.  相似文献   

19.
The blue‐stain fungus and vascular stain pathogen Ceratocystis polonica and its associated bark beetle vectors, particularly Ips typographus and I. typographus japonicus, cause significant losses to several spruce species in Eurasia. Nothing is, however, known about the population genetics of this conifer pathogen. In this study, a set of single sequence repeat (SSR) markers were developed to determine the population structure and genetic diversity of C. polonica in Europe and Japan. ISSR‐PCR primers were used to target SSR‐rich regions and specific primers were designed flanking the SSR regions found in these amplicons. The SSR primers developed for C. polonica were found to be transferable to six other Ceratocystis species from conifers, residing in the Ceratocystis coerulescens complex. Ninety‐eight isolates representing four populations of C. polonica (Austria, Norway, Poland and Japan) were tested using 10 selected polymorphic SSR markers. A high level of gene diversity was found in C. polonica as a whole (H = 0.53). Analysis of G statistics showed a low degree of population structure in Europe and a high level of gene flow between populations (Gst = 0.05, Nm = 8.5). In contrast, the Japanese and the European populations of C. polonica displayed strong genetic separation, which is likely caused by geographic isolation. The low level of population structure of C. polonica in Europe and the differentiation between the European and the Japanese fungal populations mirror previous findings for I. typographus and I. typographus japonicus, the main insect vectors of this fungus. These results support the view that the fungus and the insect have closely co‐evolved together. This study also suggests that movement of C. polonica and its vectors between Europe and Asia pose a threat to forestry on both continents and this should clearly be avoided.  相似文献   

20.
Defined populations of American (Periplaneta americana), German (Blattella germanica), and Oriental (Blatta orientalis) cockroaches, and silverfish (Lepisma saccharina) were observed after exposure to deposits (25 g/m2) of a new 1,1,1–trimethyl-N-trimethylsilane-modified, highly hydrophobic diatomaceous earth (DE) formulation by using a computer-aided device measuring motility, circadian rhythm, and mortality under defined environmental and climatic field-simulating and exposure-enforced conditions. In a humid climate (85% relative humidity) with water and food offered ad libitum, complete population eradication could be achieved on the sixth day against B. germanica, on the eighth day against P. americana, and on the ninth day against L. saccharina, respectively. No population eradication occurred within 10 days of exposure when testing B. orientalis, showing a mean survival rate of 29.4 ± 6.7 % of the populations. When comparing the species-specific mortality rates with the results obtained from corresponding reference control groups, significantly higher mortality rates could be observed in B. germanica (F = 66; df = 52; P < 0.00001), P. americana (F = 344; df =66; P < 0.00001), L. saccharina (F = 253; df = 24; P < 0.00001), and B. orientalis (F = 422; df = 11; P < 0.00001). Overall, the efficacy of the hydrophobised DE examined ranked as follows: B. germanica > P. americana (F = 51; df = 24; P < 0.00001) > L. saccharina (F = 43; df = 24; P < 0.00001) >> B. orientalis (F = 9; df = 15; P < 0.000001). DE exposure resulted in complete disruption of the circadian activity in B. germanica and P. americana, but not when tested against B. orientalis, where the species-specific circadian motility peak was still preserved at lower levels after 10 days of exposure. In contrast to the cockroach species examined, no specific circadian rhythm could be measured in the L. saccharina control and treatment groups. Results indicate that hydrophobised DE originating from freshwater diatoms modified with 1,1,1-trimethyl-N-trimethylsilane can be successfully used for the control of infestations with German and American cockroaches as well as silverfish, but not against Oriental cockroaches. It is concluded that species-specific morphological, physiological and behavioural characteristics of insects influencing DE efficacy as well as the toxicological risk of modified DE to humans deserve further investigation.  相似文献   

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