76 research outputs found
The role of the IOBC for research and implementation of biological and integrated crop protection
Die „International Organization for Biological Control of Noxious Animals and Plants (IOBC)“ wurde 1956 in Europa unter der Schirmherrschaft der „International Union of Biological Sciences (IUBS)“ gegründet. Durch „IOBC Global“ wurden 1971 sechs regionale Sektionen etabliert, die die wichtigsten biogeographischen Zonen repräsentieren. Das Hauptziel der IOBC ist die Förderung und Entwicklung des biologischen Pflanzenschutzes und seine Anwendung im integrierten Pflanzenschutz und der integrierten Produktion (IP). Die „West Palearctic Regional Section“ der IOBC (IOBC/WPRS), die das Gebiet der EU, Nord-Afrika und den Nahen Osten umfasst, hat zur Zeit 20 Arbeitsgruppen (WG) und vier Kommissionen, die kultur-, methoden- und schädlingsspezifisch gegliedert sind. Die Aufgabe der Arbeitsgruppen und Kommissionen ist es, Plattformen zu bieten, die den biologischen Pflanzenschutz, IPM/IP und andere mit dem Pflanzenschutz befasste Akteure zusammenbringen, um so die Kooperation und den Wissens- und Informationsaustausch zu fördern und eine Zusammenarbeit im Bereich der Forschung und Umsetzung nachhaltiger Pflanzenschutzmethoden und -strategien in Gang zu setzen. Die Arbeitsgruppen und Kommissionen sind offen für alle Personen, Institutionen und Organisationen – öffentlich oder privat –, die die Ziele der IOBC fördern wollen. Beispielhaft werden in diesem Beitrag drei Arbeitsgruppen genauer vorgestellt um zu zeigen, wie Aktivitäten entwickelt und Ergebnisse im biologischen Pflanzenschutz und IPM umgesetzt werden.The International Organization for Biological Control of Noxious Animals and Plants (IOBC) was founded in 1956 in Europe under the auspices of the International Union of Biological Sciences (IUBS). In 1971, IOBC Global was established with six Regional Sections that represent the world’s major biogeographical zones. The main objective of IOBC is to promote the development of biological control and its application in integrated pest management programs and integrated production. The West Palaearctic Regional Section of the IOBC (IOBC/WPRS) which covers the EU region, North Africa and the Near East has at present 20 Working Groups (WG) and four Commissions which are categorised in crop, method and pest focused groups. The role of the WG and Commissions is to offer platforms that bring biocontrol, IPM/IP and other crop protection stakeholders together to foster collaboration, exchange of information and knowledge, to initiate cooperation for research and implementation of sustainable crop protection methods and strategies. WG and Commissions are open to any person, institution and organization, public or private, that desire to promote the objectives of IOBC. Three examples of WG are discussed in more detail in the paper showing how activities are developed and outcomes implemented in biocontrol and Integrated Pest Management
Tritrophic Interactions of Transgenic Bacillus thuringiensis Corn, Anaphothrips obscurus (Thysanoptera: Thripidae), and the Predator Orius majusculus (Heteroptera: Anthocoridae)
Laboratory feeding experiments using transgenic Bacillus thuringiensis variety kurstaki (Berliner) corn plants were carried out to study the effects of B. thuringiensis-fed herbivorous prey on the predator Orius majusculus (Reuter). Host plants were a transgenic B. thuringiensis-expressing (Cry1Ab) corn hybrid and the corresponding untransformed isogenic B. thuringiensis-free corn hybrid. The herbivorous prey species used in the experiment was Anaphothrips obscurus (Müller), a thysanopteran pest of corn, not sensitive to Cry1Ab toxin. The objectives were to quantify the effects of B. thuringiensis-fed prey on the development and mortality of immature O. majusculus. There was no significant difference in total mean mortality from hatch to adult eclosion between O. majusculus nymphs reared on B. thuringiensis-fed or B. thuringiensis-free prey. Similarly, no significant differences in total developmental time of O. majusculus was detected when reared on the two different prey types. Overall mortality was low, confirming that the methodology used was appropriate. We propose this approach as an efficient standardized preregistrational testing for side effects of transgenic plants on small predators such as Orius sp
Toxicity of Bacillus thuringiensis CrylAb Toxin to the Predator Chrysoperla carnea (Neuroptera: Chrysopidae)
Laboratory feeding studies were carried out to determine the effects of the Bacillus thuringiensis (Berliner) CrylAb toxin on developmental time and mortality of Chrysoperla carnea (Stephens) larvae. A bioassay technique was developed that allowed for incorporation of the CrylAb toxin into a liquid diet that was then encapsulated within small paraffin spheres. Because only 2nd and 3rd instars can penetrate the surface of the paraffin spheres, 2 different methods were used to rear chrysopid larvae through the 1st instar. The 1st method used small foam cubes soaked in non-encapsulated, liquid diet (with or without CrylAb). The 2nd method used Ephestia kuehniella (Hübner) eggs as prey during the first instar (no CrylAb exposure). After reaching the 2nd instar, all larvae received encapsulated, artificial diet with or without CrylAb, respectively. When reared only on artificial diet containing CrylAb toxin, total immature mortality was significantly higher (57%) than in the respective untreated control (30%). Also, significantly more chrysopid larvae died (29%) that received CrylAb later during their larval development compared with the respective control (17%). Although mortality was consistently higher, no or only small differences in developmental times were observed between CrylAb-treated and untreated C. carnea larvae. C. carnea larvae required significantly more time to complete larval development when reared on artificial diet only than when reared first on E. kuehniella eggs followed by encapsulated artificial diet or on only E. kuehniella eggs, regardless of exposure to CrylAb. These results demonstrate that CrylAb is toxic to C. carnea at 100 μmg/ml of diet by using encapsulated artificial die
An Unexpected Tandem Reaction between N-Butadienyl-N-alkylketene N,O-Trimethylsilylacetals of Propionamide and Activated Dienophiles like N-Phenyl-maleimide or Acryloyl Chloride
Starting from the N-butadienyl-N-alkylpropionamides 1a-1c the corresponding N,O-trimethylsilylacetals could be obtained using the mixture of LDA and trimethylsilyl chloride in THF. The unexpected reaction sequence Diels-Alder reaction/acylation between the N-butadienyl-N-alkylketene N,O-trimethylsilylacetal of propionamide (2a-2b) and N-phenylmaleimide produced tricyclic products rac-5a-rac-5b and bicyclic products rac-6a–rac-6b with high diastereoselectivity. The reaction of the N,O-trimethylsilylacetals 2a and 2c with acryloyl chloride in a similar sequence gave the bicyclic products rac-8a and rac-8c. The stepwise synthesis of bicyclic systems of this general structure could only be successfully executed in 26% yield treating the Diels-Alder product rac-10 with LDA
Deriving criteria to select arthropod species for laboratory tests to assess the ecological risks from cultivating arthropod-resistant genetically engineered crops
Arthropods form a major part of the biodiversity in agricultural landscapes. Many species are valued because they provide ecosystem services, including biological control, pollination and decomposition, or because they are of conservation interest. Some arthropods reduce crop yield and quality, and conventional chemical pesticides, biological control agents and genetically engineered (GE) crops are used to control them. A common concern addressed in the ecological risk assessment (ERA) that precedes regulatory approval of these pest control methods is their potential to adversely affect valued non-target arthropods (NTAs). A key concept of ERA is early-tier testing using worst-case exposure conditions in the laboratory and surrogate test species that are most likely to reveal an adverse effect. If no adverse effects are observed in those species at high exposures, confidence of negligible ecological risk from the use of the pest control method is increased. From experience with chemical pesticides and biological control agents, an approach is proposed for selecting test species for early-tier ERA of GE arthropod-resistant crops. Surrogate species should be selected that most closely meet three criteria: (i) Potential sensitivity: species should be the most likely to be sensitive to the arthropod-active compound based on the known spectrum of activity of the active ingredient, its mode of action, and the phylogenetic relatedness of the test and target species; (ii) Relevance: species should be representative of valued taxa or functional groups that are most likely to be exposed to the arthropod-active compound in the field; and (iii) Availability and reliability: suitable life-stages of the test species must be obtainable in sufficient quantity and quality, and validated test protocols must be available that allow consistent detection of adverse effects on ecologically relevant parameters. Our proposed approach ensures that the most suitable species are selected for testing and that the resulting data provide the most rigorous test of the risk hypothesis of no adverse effect in order to increase the quality and efficiency of ERAs for cultivation of GE crops
Setting the record straight: a rebuttal to an erroneous analysis on transgenic insecticidal crops and natural enemies
While we think that environmental risk assessments of transgenic insect-resistant crops are important, we believe the paper by Lövei et al. (2009) advocates inappropriate summarization and statistical methods, a negatively biased and incorrect interpretation of the published data on non-target effects, and fails to place any putative effect into a meaningful ecological context. Such erroneous analyses do not serve the scientific or regulatory communities
Evaluation der Ökomassnahmen: Bereich Biodiversität
1993 führte der Bund ökologische Direktzahlungen ein; seit 1999 ist die Erbringung des ökologischen Leistungsnachweises (ÖLN) durch die Landwirtschaftsbetriebe die Voraussetzung zum Bezug von Direktzahlungen. Heute werden 97 % der landwirtschaftlichen Nutzfläche nach den Regeln des ÖLN bewirtschaftet.
Die wichtigste Massnahme des ÖLN, welche einen Einfluss auf die Biodiversität hat, ist, dass die Betriebe 7 % ihrer landwirtschaftlichen Nutzfläche (LN) als ökologische Ausgleichsflächen (öAF) auszuweisen haben (bei Spezialkulturen 3,5 %). Weitere Anforderungen des ÖLN (ausgeglichene Nährstoffbilanz, geregelte Fruchtfolge, Bodenschutz, gezielter Einsatz von Pflanzenschutzmitteln, tiergerechte Haltung der Nutztiere) können ebenfalls einen Einfluss haben, stehen jedoch weniger im Vordergrund
Assessment of risk of insect-resistant transgenic crops to nontarget arthropods
An international initiative is developing a scientifically rigorous approach to evaluate the potential risks to nontarget arthropods (NTAs) posed by insect-resistant, genetically modified (IRGM) crops. It adapts the tiered approach to risk assessment that is used internationally within regulatory toxicology and environmental sciences. The approach focuses on the formulation and testing of clearly stated risk hypotheses, making maximum use of available data and using formal decision guidelines to progress between testing stages (or tiers). It is intended to provide guidance to regulatory agencies that are currently developing their own NTA risk assessment guidelines for IRGM crops and to help harmonize regulatory requirements between different countries and different regions of the world
Laboratory toxicity studies demonstrate no adverse effects of Cry1Ab and Cry3Bb1 to larvae of Adalia bipunctata (Coleoptera: Coccinellidae): the importance of study design
Scientific studies are frequently used to support policy decisions related to transgenic crops. Schmidt et al., Arch Environ Contam Toxicol 56:221–228 (2009) recently reported that Cry1Ab and Cry3Bb were toxic to larvae of Adalia bipunctata in direct feeding studies. This study was quoted, among others, to justify the ban of Bt maize (MON 810) in Germany. The study has subsequently been criticized because of methodological shortcomings that make it questionable whether the observed effects were due to direct toxicity of the two Cry proteins. We therefore conducted tritrophic studies assessing whether an effect of the two proteins on A. bipunctata could be detected under more realistic routes of exposure. Spider mites that had fed on Bt maize (events MON810 and MON88017) were used as carriers to expose young A. bipunctata larvae to high doses of biologically active Cry1Ab and Cry3Bb1. Ingestion of the two Cry proteins by A. bipunctata did not affect larval mortality, weight, or development time. These results were confirmed in a subsequent experiment in which A. bipunctata were directly fed with a sucrose solution containing dissolved purified proteins at concentrations approximately 10 times higher than measured in Bt maize-fed spider mites. Hence, our study does not provide any evidence that larvae of A. bipunctata are sensitive to Cry1Ab and Cry3Bb1 or that Bt maize expressing these proteins would adversely affect this predator. The results suggest that the apparent harmful effects of Cry1Ab and Cry3Bb1 reported by Schmidt et al., Arch Environ Contam Toxicol 56:221–228 (2009) were artifacts of poor study design and procedures. It is thus important that decision-makers evaluate the quality of individual scientific studies and do not view all as equally rigorous and relevant
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