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1.
The occurrence, species diversity and some aspects of taxonomical affinity and host selectivity of acaropathogenic fungi associated with phytophagous, saprotrophic and predacious mites in Poland and other European countries were investigated on wild and cultivated plants, in insect feeding sites under the bark and in decayed wood. From among 33 species of fungi affecting mites only five species of Entomophthorales were separated and the most numerous were Neozygites floridana mostly on Tetranychus urticae, N. abacaridis on a few eriophyid species, and Conidiobolus coronatus attacking gamasid mites most frequently of the genus Dendrolaelaps. The most frequent mite pathogens occurring in mite communities on plants and in wood infested by insects were of the genus Hirsutella. Until now 13 of their form-species have been recognized in these habitats, but only H. kirchneri, H. necatrix and H. thompsonii (including its variety synnematosa) can be treated as exclusive oligophagous pathogens of phytophagous mites, though their potential host range seems to embrace only selected eriophyid or tarsonemid mites. Taxonomical differentiation of fungal strains was based on close morphological observations and molecular analysis of ITS region sequences. Two new species of acaropathogenic fungi were described in these studies. Hirsutella danubiensis sp. nov. was found in the tetranychid T. urticae, whereas H. vandergeesti sp. nov. affected phytoseiid mites of the genera Amblyseius, Neoseiulus, Seiulus and Typhlodromus, and the tarsonemid Tarsonemus lacustris.  相似文献   

2.
ABSTRACT Four new species of Symphypleona, Ptenothrix plumiseta, Deuterosminthurus serratus, Sminthurus annulatus, Smithurinus distinctus , are described from Korea. Especially two genera, Deuterosminthurus and Sminthurinus are new record to Korea. Korean Collembola Symphypleona add up to 18 species, 11 genera in 6 family.  相似文献   

3.
4.
A new entomopathogenic fungus, described here as Neozygites abacaridis n. sp. (Zygomycetes: Entomophthorales), has been found on the mites Abacarus hystrix, Aculodes dubius, and A. mckenziei (Acari: Eriophyidae). It differs from other Neozygites species affecting mites by its small, globose primary conidia, short-ovoid, smoky coloured capilliconidia, and very short capillary conidiophores-which are usually not longer than the spore length. This pathogen infected mite individuals in autumn (from mid-August until mid-November) on Lolium perenne, Agrostis stolonifera, and Festuca rubra. It caused 0.5-1% host's mortality in the vicinity of Siedlce (Eastern Poland) and up to 2-8%, on an average in Puszczykowo (Wielkopolski National Park near Poznań), where its prevalence on some plants reached 13%.  相似文献   

5.
A species of the fungus Neozygites (Zygomycetes: Entomophthorales) is recorded from the Antarctic mite Alaskozetes antarcticus (Acarina: Oribatidales) collected off the west coast of the Antarctic peninsula. The features of the fungus were similar to those recorded for Neozygites acaridis, and to other species of the genus recorded from mites in tropical and cool-temperate regions. This is the first report of any entomophthoralean fungus from the Antarctic region.  相似文献   

6.
Microcycle conidiation is defined as the germination of spores by the direct formation of conidia without the intervention of mycelial growth, as occurs in most normal life cycles. It is a method of asexual spore formation in which the normal life cycle of the fungus is bypassed. Spores formed through sexual reproduction and species with unicellular thalli are not included in microcycle conidiation. The term secondary conidium or secondary spore is usually, but not always, synonymous with microcycle conidiation. In the laboratory various factors, but especially temperature, can induce the microcycle condition in such fungi asAspergillus niger, Penicillium andNeurospora crassa, providing a useful tool for research. Microcycle conidiation has also been reported in a broad range of species in nature, and comprises a normal part of the life cycle in several groups, including the Entomophthorales, Taphrinales, Clavicipitales, Uredinales, Ustilaginales, Tremellales and Exobasidiales. The presence of a microcycle in such fungi undoubtedly provides a survival mechanisn for spores that encounter unfavorable conditions.  相似文献   

7.
Résumé Uniquement connue du sud des Etats-Unis d'Amérique, l'EntomophthoraleNeozygites fumosa (Speare) Remaudière & Keller a été retrouvée en République populaire du Congo, où elle attaque la Cochenille du manioc,Phenacoccus manihoti Matile-Ferrero [Hom.: Coccoidea Pseudococcidae]. De légères variations d'ordre biométrique sont mises en évidence au sein de l'espèce fongique. A ce jour, parmi les Entomophthorales mentionnées dans la littérature comme pathogènes de Cochenilles, seules deux espèces peuvent être retenues avec certitude:Neozygites fumosa etConidiobolus pseudococci Speare (Tyrrell & MacLeod), toutes deux pathogènes dePseudococcidae.
Summary The entomophthoraceous fungus,Neozygites fumosa (Speare) Remaudière and Keller, which was only known from the south of the U.S.A., was found in the People's Republic of the Congo, on the Cassava mealybug,Phenacoccus manihoti Matile-Ferrero [Homoptera: Coccoidea, Pseudococcidae]. Slight biometrical variations appear within the fungal species. At the present time, among the Entomophthorales cited in the literature as parasitizing Coccoidea, two species only can be retained with certainty:Neozygites fumosa andConidiobolus pseudococci Speare (Tyrrell and MacLeod), both attackingPseudococcidae.
  相似文献   

8.
Abstract. The effects of food quality on growth and body composition of the collembolan Orchesella cincta (L.) (Entomobryidae) were investigated to determine optimal values for dietary nitrogen.Hyphae of Cladosporium cladosporioides containing 2.2%, 2.7%, 4.0% and 6.2% nitrogen were used as food sources.These different nitrogen contents were obtained by adjusting the medium on which the fungi were grown.Collembola were fed on one of these four food sources for 8 weeks.
O. cincta grew faster and reached a higher asymptotic body mass when fed on fungi with 4% or 6.2% nitrogen content: this effect decreased with higher nitrogen content.The lipid concentration in the animals was negatively correlated with dietary nitrogen content, whereas protein concentration was positively correlated.Glycogen concentration was not found to correlate with the composition of the food.
A mechanism is proposed by which O. cincta compensates for low dietary nitrogen by consuming more to maintain a relatively constant amount of protein in its body and, as a result, accumulates more fat than animals fed on fungi with a higher nitrogen content.  相似文献   

9.
The entomopathogenic fungus Neozygites parvispora (Entomophthorales: Zygomycetes) grows in vitro as irregularly rod-shaped hyphal bodies in a complex medium. In order to simplify the medium composition and determine growth-promoting compounds for the cultivation of this fungus, we were looking for a rapid and quantitative method to estimate the number of living cells in small volumes of liquid culture. A colorimetric method for the determination of cell densities using MTT [3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] proved to be more accurate and timesaving than conventional hemocytometer counting.  相似文献   

10.
The spider mites Tetranychus urticae Koch and Tetranychus evansi Baker and Pritchard are important pests of horticultural crops. They are infected by entomopathogenic fungi naturally or experimentally. Fungal pathogens known to cause high infection in spider mite populations belong to the order Entomophthorales and include Neozygites spp. Studies are being carried out to develop some of these fungi as mycoacaricides, as stand-alone control measures in an inundative strategy to replace the synthetic acaricides currently in use or as a component of integrated mite management. Although emphasis has been put on inundative releases, entomopathogenic fungi can also be used in classical, conservation and augmentative biological control. Permanent establishment of an exotic agent in a new area of introduction may be possible in the case of spider mites. Conservation biological control can be achieved by identifying strategies to promote any natural enemies already present within crop ecosystems, based on a thorough understanding of their biology, ecology and behaviour. Further research should focus on development of efficient mass production systems, formulation, and delivery systems of fungal pathogens.  相似文献   

11.
Summary. The natural occurrence of fungal pathogens of aphids and their ecological host range was investigated in Tunisia from 2009 to 2012. The survey focused on aphid infesting different crops and weeds and included 10 different aphid species. Samples were collected from eight agricultural crops sites belonging to three different bioclimatic zones. Four pathogens from the phylum Entomophthoromycota were found to occur naturally in Tunisian ecosystems: Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae), Conidiobolus obscurus (Entomophthorales: Ancylistaceae) and Neozygites fresenii (Neozygitales: Neozygitaceae). The occurrence of entomophthoralean fungi depended on the sampling area, the bioclimatic zone, and aphid species. P. neoaphidis and E. planchoniana were the predominant pathogens infecting a wide range of aphid species whereas C. obscurus and N. fresenii were sporadically present on a limited number of aphid species. This study is the first survey on ecological host range of entomophthoralean fungi in Tunisia, and the first documentation of C. obscurus and N. fresenii to occur in Tunisia and Maghreb Region.  相似文献   

12.
The spectrum of entomophthoroid fungal species parasitising aphids on cereal crops and a study of the phenology and prevalence of these pathogens were investigated in Argentina. The studies were conducted at six different sites cultivated with crops of Triticum aestivum (wheat), Avena sativa (oats) and Sorghum bicolor (sorghum) during two consecutive years. Entomopathogenic fungi from the new phylum Entomophthoromycota were recorded from six aphid species on cereals in Argentina: Rhopalosiphum maidis, Rhopalosiphum padi, Rhopalosiphum rufiabdominalis, Schizaphis graminum, Sitobion avenae and Sipha maydis. Three species of entomophthoroid fungi were found infecting these aphid species: Pandora neoaphidis, Zoophthora radicans (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae). Entomophthoroid fungal infections occurred mostly in autumn–winter seasons (March–August), and coincided with periods of high relative humidity and comparatively low temperatures. This study represents the first base‐line characterisation of entomophthoroid fungi infecting aphids on cereal crops in Argentina.  相似文献   

13.
The entomopathogenic fungus Neozygites parvispora (Entomophthorales: Zygomycetes) grows in vitro as irregularly rod-shaped hyphal bodies in a complex medium. In order to simplify the medium composition and determine growth-promoting compounds for the cultivation of this fungus, we were looking for a rapid and quantitative method to estimate the number of living cells in small volumes of liquid culture. A colorimetric method for the determination of cell densities using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] proved to be more accurate and timesaving than conventional hemocytometer counting.  相似文献   

14.
Conidiobolus coronatus (Entomophthorales), a pathogen of human and some insects, was isolated from dead specimens of the aphid Neotoxoptera formosana present on chives leaves. C. coronatus infected aphids could pose a threat to growers health. Pest control strategies of N. formosana may also contribute to reduce the human infection risk by C. coronatus.  相似文献   

15.
Abstract. 1. Consumption (in Joules), partitioning of assimilated energy between maintenance (standard metabolism and locomotory activity) and prcduction (growth and reproduction) and assimilation efficiency were studied in the laboratory using adults of the coexisting species Orchesella cincta (L.) and Tomocents minor Lubbock (Collembola, Entomobryidae).
2. A higher energy demand for maintenance was established in O.cincta , compared with T.minor , caused by a higher mobility and a higher live weight-specific oxygen consumption (metabolic rate).
3. The energy required for higher maintenance in O.cincta , compared with T.minor , was derived from production, both from growth and reproduction.
4. The increase in live weight (in mg) during a moulting interval (feeding instar plus reproductive instar) was less in O.cincta than in T.minor , and was less in males than in females.
5. Reproduction (in Joules) was less in O.cincta than in T.ninor . The numbers of eggs produced were equal, but their energetic content was less in O.cincta . Survival of the eggs was similar.
6. Consumption (in Joules) and assimilation efficiency (on an energetic basis) during a moulting interval (feeding instar plus reproductive instar) were similar in both species.  相似文献   

16.
杨群芳  叶华智  张敏 《昆虫学报》2008,51(6):595-600
本文同时采用分离和电镜扫描技术研究了光滑足距小蠹Xylosandrus germanus(Blan dford)不同发育阶段坑道和贮菌器内真菌种类的组成和变化。Ambrosiella hartigii是光滑足距小蠹扩散、蛀孔、越冬和体壁新硬化的成虫贮菌器内唯一分离到的真菌,而刚羽化的雌成虫贮菌器中没有分离到任何真菌种类,体壁新硬化的成虫贮菌器中真菌的分离频率最低。坑道内共分离到4种真菌:A. hartigii,Acremonium kiliense和2种镰刀菌Fusarium spp.。从卵期到蛹期的坑道中,A. hartigii总是能被分离到,占分离物总数的百分率较高,达40%~60%;而在成虫期坑道中,A. kilienseFusarium sp.1被分离率较高,都为34.6%。扫描电镜观察表明,A. hartigii为卵期到蛹期坑道中的优势种,而镰刀菌Fusarium spp.则是成虫期坑道中的优势种。这些结果均表明,Ambrosiella hartigii,Acremonium kiliense和2种镰刀菌Fusarium spp.是光滑足距小蠹的虫道真菌,而且这些真菌种类组成和优势种类是随着蠹虫的发育阶段而变化的。真菌种类的组成和变化可 能与幼虫和成虫的营养需求以及虫道真菌的生长特性有关。  相似文献   

17.
山东省常见虫霉目真菌调查   总被引:6,自引:0,他引:6  
综合国内已发表的文献和近几年所采集的样本 ,共报道了山东省的 1 6种虫霉目真菌 ,分别隶属于虫霉目 3科 9属。介绍了该省虫霉菌的发生和流行的几个特征 ,并做了简要的分析  相似文献   

18.
The existence of aggregation pheromones is demonstrated in the Collembola Orchesella cincta, Orchesella villosa, and Tomocerus minor. Places conditioned by these animals can be considered as pheromone-sources, causing aggregation. Although for Tomocerus minor perception is not strictly species specific, all species investigated appear to be more responsive to their own pheromone than to those produced by other species. Both males and females appear to produce and perceive the aggregation pheromone. The distant action of the pheromone points to an olfactorially acting pheromone, in the perception of which the antennae play an important rôle. The behavioural reaction of the perceiving animals is orthokinetic.  相似文献   

19.
1978-1979年, 在福建省福鼎县的油桐枝条上发现一种假尾孢菌, 经人工培养及致病性的试验, 证明了它有病原性, 与已知真菌的Pseudocercospora aleuritidis Miy.Deighton有别, 故鉴定为新种, 命名为福鼎假尾孢Pseudocercospora fudlinga Huang, sp.nov.该新种分生孢子特别小, 大小为12-30×1.6-2.1μ。模式标本存于福建林学院标本室。  相似文献   

20.
Studies on diseases of mites caused by entomopathogenic fungi have been undertaken in Poland about a half a century later than in West European countries. Nevertheless, during the last 30 years almost 40 species of arthropod pathogenic fungi have been identified, among them 23 species of Entomophthorales, 12 species of Hyphomycetales and four species of ectoparasitic Laboulbeniales. The most common are representatives of the genus Hirsutella , found both on phytophagous and parasitic or predaceous mites. Percentage infection by H. thompsonii in populations of some tarsonemid and eriophyid mites increases slowly from the end of spring reaching a maximum of 30-60% in August-September. Neozygites floridana is a common entomophthoralean species causing epizootics in spider mite populations; infection also peaks in late summer and autumn. The most numerous fungal taxa have been identified from the resting spores produced internally within the body of the host and show features of the genus Tarichium . From the total number of the taxa recorded within these studies, 22 were described as species new to science. Current research on invertebrate pathology in Poland includes many groups of mites and among their pathogens fungal diseases seem to be the most common.  相似文献   

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