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The review concerns the latest theories of biological control of pests and weeds and protection of benefitial and neutral species. Registration requirements to microbial biopreparations, introduction and other biological interventions are considered. Article explains why in recent years the biological and chemical controls are not opposite each other as strongly as in early projects. The trial of field applications of local strain of fungus Beauveria bassiana against Melolontha melolontha is described and the elucidation that utilization of local species to plant protection is less risky was given.
We carried out an experiment with using the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. for sanitation of active infested trees. We used 15 active infested trees from which 5 stems were treated with an insecticide, 5 were treated with solution of the tested entomopathogenic fungus and 5 were left as control. The used insecticide was pyretroid Fury 10 EW. We used a biopreparation based on the entomopathogenic fungus B. bassiana in form of wettable powder. The material was diluted. The suspension contained 107spores of the tested entomopathogenic fungus in 1 ml. The suspension was applied across the whole stem surface. We succeeded to infect about 28.75% of Ips typographus L. individuals in the treated stems. The number of live individuals was comparable with the variant using the insecticide.
Entomopathogenic fungi attack the host insect and therefore may be potentially used for insect control. Penetration of cuticle is achieved by a combination of mechanical pressure and enzymatic degradation. The entomopathogenic fungi produce a variety of exocellular hydrolytic enzymes: proteases, chitinases and lipases, which are capable to digest the major components of insect cuticle. This review describes the characteristics of these enzymes and their role in pathogenesis.
Six fungal species, Aspergillus flavus Link ex Fr., Beauveria bassiana (Bals.) Vuill., Acremonium sensu Gams, Fusarium sp. Link ex Fr., Paecilomyces farinosus (Holm. ex Gray) Brown et Smith as well a Paecilomyces fumosoroseus (Wize) Brown et Smith, have been isolated as result of studies on entomopathogenic fungi of the satin moth Stilpnotia salicis. The epizootic induced by the fungus B. bassiana in 1994 caused about 92% reduction of the pest population. That has been noted for the first time in a natural population of S. salicis in Poland.
Dokonano oceny zdolności porażania prusaków (Blattella germanica L.) przez różne szczepy grzyba Beauveria bassiana,- również przez szczepy otrzymane drogą pasażu. Badano prusaki dojrzałe, zróżnicowane pod względem wieku, płci i pochodzenia (laboratoryjne i tzw. terenowe). Testowane szczepy wykazały zróżnicowany poziom patogeniczności w stosunku do badanych populacji prusaków; a procent śmiertelności owadów zależał od właściwości patogenicznych danego szczepu, ilości zarodników grzyba w pokarmie oraz obu płci tych owadów. Z badanych szczepów najbardziej skuteczny w redukcji liczebności prusaków okazał się szczep Beauveria bassiana oznaczony w kolekcji szczepów Instytutu Ekologii PAN pod numerem Bb 23.
Entomopathogenic fungi have great potential as biological control agents against insect pests. So they are being developed worldwide for the control of many pests of agricultural importance. But their effect on non-target insects, such as natural enemies has been a matter of great concern. Recently we came across an entomopathogen infecting a laboratory culture of Zygogramma bicolorata, a potential biocontol agent of noxious weed, Parthenium hysterophorus. The pathogen was isolated from the grubs and beetles and identified as Beauveria bassiana. In the present paper, the entomopathogen, B. bassiana is reported and described for the first time from the laboratory culture of Z. bicolorata.
The study was aimed at estimating species composition and abundance of entomopathogenic fungi in the Chojnowski Landscape park. The effect of site, season (spring, summer, autumn) and temperature on the frequency of isolation of entomopathogenic fungi was also analysed. The effect of the first two factors was estimated based on the analysis of soil samples taken from meadow 1, forest 1 and orchard in spring, summer and autumn 2010. Three species of entomopathogenic fungi (Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea) were isolated in the study area. Site and temperature affected the frequency of isolation of particular species. On meadow 1 and in orchard M. anisopliae appeared to be the dominating species while forest 1 was dominated by B. bassiana. From among meadow and forest sites sampled in the autumn, forest 3 (nature reserve) was characterised by the highest density of entomopathogenic fungi. M. anisopliae and B. bassiana were most often isolated from meadow sites while B. bassiana and I. fumosorosea - from forest sites. B. bassiana and I. fumosorosea infected insects with significantly higher frequency at 20°C than at 25°C.
The effects of pyriproxyfen were determined on the cellular immunity and phenoloxidase activity in the 4th instar larvae of Chilo suppressalis Walker. The bioassay results revealed the effective concentrations of: 10L : 18C, 30L : 72C and 50L : 190C μg · ml–1. The sole effect of 18 and 72 μg · ml–1 concentrations at intervals of 1–3 h caused a higher number of total hemocytes in the treated larvae than the control, but the reverse results were observed after 6–24 h. The number of plasmatocytes was lower than that of the control for intervals of 3–24 h but the number of granulocytes was higher than the control after 1–3 h although no significant differences were observed at the other times. In the treated larvae, the activities of phenoloxidase were higher and lower than those of the control after 1–3 h and 6–24 h, respectively. The combined effects of pyriproxyfen and the entomopathogenic fungus, Beauveria bassiana isolate B3 caused higher numbers of total hemocytes, plasmatocytes, and granulocytes in the treated larvae by use of the three concentrations of pyriproxyfen, at intervals of 6 and 12 h. Although the numbers of nodules in the larvae treated with concentrations of 18 μg · ml–1 were higher than those of other treatments, the overall numbers were lower than those of the control. Finally, the activity of phenoloxidase in the treated larvae was higher than that of the control, at intervals of 6 and 12 h post-treatment. Findings of the current study indicate an intervening role of pyriproxyfen in the cellular immunity of C. suppressalis to entomopathogenic objects.
Inter-microsatellite PCR (ISSR-PCR) markers were used to identify and to examine the genetic diversity of eleven Beauveria bassiana isolates with different geographic origins. The variability and the phylogenetic relationships between the eleven strains were analyzed using 172 ISSR-PCR markers. A high level of polymorphism (near 80%) was found using these molecular markers. Seven different isolates showed exclusive bands, and ISSR primer 873 was able to distinguish between all the strains. The dendrogram obtained with these markers is robust and in agreement with the geographical origins of the strains. All the isolates from the Caribbean region were grouped together in a cluster, while the other isolates grouped in the other cluster. The similarity exhibited between the two clusters was less than 50%. This value of homology shows the high genetic variability detected between the isolates from the Caribbean region and the other isolates. ISSR-PCR markers provide a quick, reliable and highly informative system for DNA fingerprinting, and allowed the identification of the different B. bassiana isolates studied.
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