Evaluation of Insect Associated and Plant Growth Promoting Fungi in the Control of Cabbage Root Flies

Delia radicum L. or cabbage maggot is an important pest for Brassicaceous crops. There are currently no registered chemical control agents for its control in Slovenia. Fungal control agents for cabbage maggot were therefore sought among nine rhizosphere-compatible and plant growth-promoting, soil-adapted, and entomopathogenic species to cabbage maggots and were assayed in in vitro and soil laboratory bioassays. In the in vitro tests, the conidial suspensions were applied directly to cabbage maggot eggs. The soil tests mimicked pathways of natural exposure of various insect life stages to the fungal strains. Conidial concentrations used in soil tests were comparable to economic rates for in-furrow application. The following fungi were tested: Trichoderma atroviride P. Karst. (2 isolates), Trichoderma koningiopsis Samuels, C. Suárez & H.C. Evans (1), Trichoderma gamsii Samuels & Druzhin. (3), Beauveria brongniartii (Saccardo) Petch (1), Beauveria bassiana (Balsamo-Crivelli) Vuillemin (2), Metarhizium robertsii J.F. Bisch., Rehner & Humber (1), Metarhizium anisopliae (Metschn.) Sorokin (4), Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel-Jones & Samson (2), and Clonostachys solani f. nigrovirens (J.F.H. Beyma) Schroers (2). Abbott's corrected mortality in the in vitro tests ranged from 0.0 ± 18.9 to 47.6 ± 9.0% and in the soil test from 2.4 ± 13.0 to 68.2 ± 21.5%. Seven isolates (B. bassiana [isolate 1174], C. solani [1828], M. anisopliae [1154 and 1868], T. atroviride [1872], T. koningiopsis [1874], and T. gamsii [1876]) caused significant cabbage maggot mortality in either in vitro or soil tests. The importance of fungal ecology as a criterion during the screening of potential biological control agents is discusse

Laboratory investigation of cauliflower-fungus-insect interactions for cabbage maggot control

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)The cabbage maggot (also known as cabbage root fly [CRF]; Delia radicum L.) is a serious pest of brassicas. The pest's soil-dwelling larvae are especially damaging to young brassica transplants. In light of toxic soil insecticide phase-out novel biocontrol management solutions are sought for. Our research is focused on the development of a biological control strategy involving cauliflower plantlet inoculation with insect pathogenic fungi. This article presents the results of a laboratory investigation of cauliflower × microbe × CRF interactions. Seven isolates of fungi (entomopathogenic and rhizosphere-competent fungi and soil saprotrophs) were tested for their pathogenicity to CRF and their effects on cauliflower plantlets. The laboratory experiments were performed in sterilized substrate. Several strains significantly increased CRF mortality, some at par with a commercial bioinsecticide based on B. bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae). All strains colonized the rhizoplane, however to varying extent. Some isolates were also reisolated from within healthy plant tissues and thus identified as endophytes. The method of applying conidia had a significant effect on survival and weight of seedlings and rhizoplane and endophytic colonization rates. Two Metarhizium brunneum Petsch (Hypocreales: Clavicipitaceae) isolates exhibited plant growth promotion effects when ungerminated seeds were coated with conidia. The ecological implications of plant × microbe × pest interactions and options for improving the effectiveness of a fungal-based biological CRF management strategy are discussed

Preliminary results of survey on food safety aspects of drone brood from Apis mellifera L.

Drone brood removal is a common practice for the control of the honeybee parasite Varoa destructor in beehives of Apis mellifera L. in Switzerland and other European countries. At present, the removed drone brood is not used. The demand for alternative protein sources is growing and drone brood has a big potential to become a new food product and a new income for beekeepers. In contrast to insects currently produced for food, honeybees feed in an open system in the environment, which is difficult to control. Therefore, food borne pathogens from the environment on drone brood need to be assessed carefully. We analysed samples of drone brood from eight Swiss apiaries regarding important food borne pathogens. This survey gives a first overview on microbiological food safety of drone brood from A. mellifera. Based on our results, further studies will be conducted to develop a process of drone brood production that is safe regarding food borne pathogens

Evaluation of insect associated and plant growth promoting fungi in the control of cabbage root flies

Delia radicum L. or cabbage maggot is an important pest for Brassicaceous crops. There are currently no registered chemical control agents for its control in Slovenia. Fungal control agents for cabbage maggot were therefore sought among nine rhizosphere-compatible and plant growth-promoting, soil-adapted, and entomopathogenic species to cabbage maggots and were assayed in in vitro and soil laboratory bioassays. In the in vitro tests, the conidial suspensions were applied directly to cabbage maggot eggs. The soil tests mimicked pathways of natural exposure of various insect life stages to the fungal strains. Conidial concentrations used in soil tests were comparable to economic rates for in-furrow application. The following fungi were tested: Trichoderma atroviride P. Karst. (2 isolates), Trichoderma koningiopsis Samuels, C. Suárez & H.C. Evans (1), Trichoderma gamsii Samuels & Druzhin. (3), Beauveria brongniartii (Saccardo) Petch (1), Beauveria bassiana (Balsamo-Crivelli) Vuillemin (2), Metarhizium robertsii J.F. Bisch., Rehner & Humber (1), Metarhizium anisopliae (Metschn.) Sorokin (4), Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel-Jones & Samson (2), and Clonostachys solani f. nigrovirens (J.F.H. Beyma) Schroers (2). Abbott's corrected mortality in the in vitro tests ranged from 0.0 ± 18.9 to 47.6 ± 9.0% and in the soil test from 2.4 ± 13.0 to 68.2 ± 21.5%. Seven isolates (B. bassiana [isolate 1174], C. solani [1828], M. anisopliae [1154 and 1868], T. atroviride [1872], T. koningiopsis [1874], and T. gamsii [1876]) caused significant cabbage maggot mortality in either in vitro or soil tests. The importance of fungal ecology as a criterion during the screening of potential biological control agents is discusse

Direct plantlet inoculation with soil or insect-associated fungi may control cabbage root fly maggots

A potential Delia radicum biological control strategy involving cauliflower plantlet inoculation with various fungi was investigated in a series of laboratory and glasshouse experiments. In addition to entomopathogenic fungi, fungi with a high rhizosphere competence and fungi with the ability to survive as saprotrophs in soil were tested. The following fungal species were evaluated in the experiments: Trichoderma atroviride, T. koningiopsis, T. gamsii, Beauveria bassiana, Metharhizium anisopliae, M. brunneum and Clonostachys solani. A commercial carbosulfan-based insecticide was used as a positive control. Additionally, two commercial products, one based on B. bassiana (Naturalis) and one on Bacillus thuringiensis (Delfin) were used as reference biocontrol agents. The aims were (i) to assess the pathogenicity of the selected fungal isolates to Delia radicum, (ii) to evaluate the fungal isolates’ rhizosphere competence, with the emphasis on the persistence of the original inoculum on the growing roots, (iii) to assess possible endophytic plant tissue colonization, and (iv) to evaluate potential plant growth stimulating effects of the added inoculi. Significant pathogenicity of tested fungi against Delia radicum was confirmed in in vitro and glasshouse experiments. All tested fungi persisted on cauliflower rhizoplane. More importantly, the added fungi were found on thoroughly washed roots outside the original point of inoculation. This provided us with evidence that our tested fungi could be transferred via or grow with the elongating roots. In addition to colonizing the rhizoplane, some fungi were found inside the plant root or stem tissue, thus exhibiting endophytic characteristics. The importance of fungal ecology as a criterion in appropriate biological control agent selection is discussed

A method for imaging water transport in soil–snow systems with neutron radiography

Liquid water at the ground–snow interface is thought to play a crucial role in the release of glide-snow avalanches, which can be massive and threaten infrastructure in alpine regions. Several mechanisms have been postulated to explain the formation of this interfacial water. However, these mechanisms remain poorly understood, in part because suitable measurement techniques are lacking. Here, we demonstrate the use of neutron radiography for imaging water transport in soil–snow systems. Columns of sand, gravel and snow were used to simulate the capillary forces of the soil–vegetation–snow layering found in nature. The columns were connected to a water reservoir to maintain a constant-pressure boundary condition and placed in a climatic chamber within the neutron beam. We show that neutron radiography is capable of measuring changes in the optical density distribution (related to liquid water content) within all three layers of the model system. Results suggest that a porous interface between the sand and snow may induce the formation of a water layer in the basal snowpack. Improved understanding of the water transport in soil–snow systems should lead to better prediction of glide-snow avalanche release and could also benefit other fields such as snow hydrology.ISSN:0260-3055ISSN:1727-564

Ausstellung Justizvollzugsanstalt Hindelbank

Hindelbank erzählt die Geschichte eines prächtigen Schlosses. Ein mächtiger Patrizier liess es vor 300 Jahren bauen. 1866 kaufte es der Kanton Bern. Er betreibt darin bis heute eine Anstalt für Frauen, seit 1896 als Arbeits- und dann als Strafanstalt. In dieser Zeit entwickelt sich Bern aus dem feudalen Ancien régime über die liberale Kantonsverfassung als Teil des neuen schweizerische Bundesstaats mit Demokratie, Rechtsstaat, Gewaltenteilung Menschenrechten und Menschen mit Rechten. Hindelbank zeigt die Entwicklung der bernischen Armenpolitik, der landesweiten administrativen Versorgung und des Strafvollzugs. Dieser wandelt sich von der willkürlichen Einweisung zum gerichtlich verfügten Freiheitsentzug mit dem Ziel der Resozialisierung. Die anfänglich ungeeigneten Räume im Schloss werden erst spät durch Neubauten erweitert und den gesetzlichen Anforderungen angepasst. Hindelbank macht am Beispiel von Frauen den staatlichen Umgang mit Straftäterinnen und Straftätern sichtbar. Die Freiheitsstrafe sperrt sie aus der Gesellschaft aus; dies mit dem Ziel dass die Frauen sich sozial wieder integrieren und künftig straffrei leben. Dabei gilt es, Schäden bei den Betroffenen zu vermeiden. Auch wenn sie durch ihre Taten anderen Menschen und deren Angehörigen Schaden zugefügt haben. Hindelbank beleuchtet anhand der bis 1981 praktizierten administrativen Versorgung auch einen dunklen Aspekt der Schweizer Geschichte. Er stellt uns vor die Frage, wie spätere Generationen unser heutiges Handeln beurteilen werden