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Disturbed energy metabolism after neonicotinoid exposure as cause of altered homing flight activity of honey bees
Get PDFEffects of chemical and biological Plant Protection Products on R&D colonies of the Buff-Tailed Bumblebee Bombus terrestris (2.5 Part 1)
Get PDFBumblebees (Bombus terrestris) are exposed daily to Plant Protection Products through their foraging and feeding activities. Through all possible means of contact with pesticides, consumption through sugarwater is the most severe. In the present study, lethal and sublethal effects of the consumption of sugarwater solutions with the pesticides Sivanto WG (flupyradifuron), Exalt SC (spinetoram) and Oikos EC (azadirachtin) were studied using a sequential dilution testing scheme of 1/1 and 1/10 of the maximum field recommended concentration (MFRC). For the weekly assessment, parameters such as the survival of the mother queen, of workers and drones, the formation of gynes, and the weight and volume of the colonies were recorded. Moreover, by the end of the colony’s life, the total number of formed workers/drones, the number of newborn gynes and queen brood were also recorded. The IOBC side-effect classes for laboratory trials were applied in order for the results to be categorized and conclusions made. Both tested concentrations of Sivanto WG (flupyradifuron) were slightly harmful for queen, worker and drone populations, Exalt SC (spinetoram) was harmful at 1/1 dilution but only slightly harmful at the 1/10 dilution, and both concentrations of Oikos EC (azadirachtin) were slightly harmful for workers and drones but toxic for queens at both dilutions.Bumblebees (Bombus terrestris) are exposed daily to Plant Protection Products through their foraging and feeding activities. Through all possible means of contact with pesticides, consumption through sugarwater is the most severe. In the present study, lethal and sublethal effects of the consumption of sugarwater solutions with the pesticides Sivanto WG (flupyradifuron), Exalt SC (spinetoram) and Oikos EC (azadirachtin) were studied using a sequential dilution testing scheme of 1/1 and 1/10 of the maximum field recommended concentration (MFRC). For the weekly assessment, parameters such as the survival of the mother queen, of workers and drones, the formation of gynes, and the weight and volume of the colonies were recorded. Moreover, by the end of the colony’s life, the total number of formed workers/drones, the number of newborn gynes and queen brood were also recorded. The IOBC side-effect classes for laboratory trials were applied in order for the results to be categorized and conclusions made. Both tested concentrations of Sivanto WG (flupyradifuron) were slightly harmful for queen, worker and drone populations, Exalt SC (spinetoram) was harmful at 1/1 dilution but only slightly harmful at the 1/10 dilution, and both concentrations of Oikos EC (azadirachtin) were slightly harmful for workers and drones but toxic for queens at both dilutions
Biopesticides and pollinators – Examples and requirements on risk assessment from a technical perspective
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Honeybee brood testing under semi-field and field conditions according to Oomen and OECD GD 75: is there a difference of the brood termination rate?
Get PDFAccording to current European regulations on the risk assessment of plant protection products, the risk on honey bee larvae or honey bee brood has to be addressed. If the assessment indicates, that a potential risk cannot be excluded based on data derived from laboratory studies, two higher-tier options are given by the EFSA bee Guidance Document to refine this under more realistic conditions: the Oomen bee brood feeding test and brood studies performed according to the OECD Guidance Document 75. Both study types focus on the brood termination rate (BTR) as the key endpoint. While the Oomen brood test investigates the brood development after the acute or chronic administration of a test item spiked sugar solution to unconfined colonies, brood studies according to OECD GD 75 are performed under semi-field confined exposure conditions and examine potential effects on the bee brood after the overspray of a bee attractive flowering crop. However, the evaluation of historical data from semi-field studies according to OECD GD 75 showed a strong variability of the BTR of pre-imaginal stages developing from marked eggs (BTReggs) in the control. As an alternative, field studies according to EPPO 170 which comprise bee brood evaluations according to OECD GD 75 were considered to produce more reliable termination data. The statistical analysis of available control data shows that Oomen feeding studies and bee brood studies performed under field conditions lead to significantly lower BTReggs of = 20% compared to semi-field bee brood studies for which a mean BTR of about 30% is observed. Moreover, studies with unconfined colonies show a high proportion of control replicates with BTReggs =30% and =40% indicating a higher reliability compared to semifield studies. A comparison of the possibilities and limitations of the three methods shows the strength of each method. In Oomen studies, the exposure of the brood and of the hive bees only can be regarded as artificial. However, the test concentrations can be adjusted to specific needs and to different feeding durations of at least one (acute) or 9 days (chronic). Furthermore, the absence of ‘caging effects’, the low dependency on climatic or crop conditions, the potential to test also herbicides which control dicotyledonous plants (since no crop plant is adversely affected by its mode of action) and an exposure period of at least nine days in chronic Oomen studies are crucial advantages. In contrast, the exposure scenarios of the two other methods are much more realistic and especially for semi-field studies a worst-case situation. Moreover, they also include exposure via pollen and exposure levels and durations, which strongly depend on the application rate and the flowering period of the treated crop. Whereas a dilution of plant protection product residues cannot be excluded during the exposure period in studies with unconfined colonies due to the shift to untreated flowering plants in the surrounding, this is not given for semi-field studies.According to current European regulations on the risk assessment of plant protection products, the risk on honey bee larvae or honey bee brood has to be addressed. If the assessment indicates, that a potential risk cannot be excluded based on data derived from laboratory studies, two higher-tier options are given by the EFSA bee Guidance Document to refine this under more realistic conditions: the Oomen bee brood feeding test and brood studies performed according to the OECD Guidance Document 75. Both study types focus on the brood termination rate (BTR) as the key endpoint. While the Oomen brood test investigates the brood development after the acute or chronic administration of a test item spiked sugar solution to unconfined colonies, brood studies according to OECD GD 75 are performed under semi-field confined exposure conditions and examine potential effects on the bee brood after the overspray of a bee attractive flowering crop. However, the evaluation of historical data from semi-field studies according to OECD GD 75 showed a strong variability of the BTR of pre-imaginal stages developing from marked eggs (BTReggs) in the control. As an alternative, field studies according to EPPO 170 which comprise bee brood evaluations according to OECD GD 75 were considered to produce more reliable termination data. The statistical analysis of available control data shows that Oomen feeding studies and bee brood studies performed under field conditions lead to significantly lower BTReggs of = 20% compared to semi-field bee brood studies for which a mean BTR of about 30% is observed. Moreover, studies with unconfined colonies show a high proportion of control replicates with BTReggs =30% and =40% indicating a higher reliability compared to semifield studies. A comparison of the possibilities and limitations of the three methods shows the strength of each method. In Oomen studies, the exposure of the brood and of the hive bees only can be regarded as artificial. However, the test concentrations can be adjusted to specific needs and to different feeding durations of at least one (acute) or 9 days (chronic). Furthermore, the absence of ‘caging effects’, the low dependency on climatic or crop conditions, the potential to test also herbicides which control dicotyledonous plants (since no crop plant is adversely affected by its mode of action) and an exposure period of at least nine days in chronic Oomen studies are crucial advantages. In contrast, the exposure scenarios of the two other methods are much more realistic and especially for semi-field studies a worst-case situation. Moreover, they also include exposure via pollen and exposure levels and durations, which strongly depend on the application rate and the flowering period of the treated crop. Whereas a dilution of plant protection product residues cannot be excluded during the exposure period in studies with unconfined colonies due to the shift to untreated flowering plants in the surrounding, this is not given for semi-field studies
Do pollen foragers represent a more homogenous test unit for the RFID homing test, when using group-feeding?
Get PDFHoneybee viruses in novel hosts – Studying agrochemical-pathogen stress combination in wild bees
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Findings and perspectives of a 23-year long-term field trial on integrated plant protection against fungal pathogens in winter wheat
Get PDFZur Entwicklung von Konzepten zum integrierten Pflanzenschutz wurde im Jahr 1995 in Dahnsdorf (Land Brandenburg) ein Versuchsfeld des Julius Kühn-Institutes eingerichtet und unterschiedliche Dauerfeldversuche angelegt. Im Rahmen des vor Ort größten und ältesten Dauerfeldversuches „Strategievergleich umweltschonender Pflanzenschutz“ werden in diesem Beitrag die Effekte einer 50%igen Reduktionsstrategie in der Phase 1 (1997 bis 2007) bzw. einer konsequenten Umsetzung des integrierten Pflanzenschutzes (IPS) in der Phase 2 (2008 bis 2013) und modifiziert in der Phase 3 (2014 bis 2019) gegenüber einer praxisnahen Strategie, der guten fachlichen Praxis (GfP), im Hinblick auf den situationsbezogenen Pflanzenschutz gegen pilzliche Schadorganismen im Winterweizen untersucht. Während in den ersten beiden Phasen des Versuches (1997 bis 2013) in den Strategien identische Sorten angebaut wurden, erfolgte in der Phase 3 eine Erweiterung um den Baustein Sorte. Die am häufigsten aufgetretenen Krankheiten waren Blattseptoria (Zymoseptoria tritici, Parastagonospora nodorum (syn. Septoria nodorum)), Braunrost (Puccinia triticina) und Gelbrost (Puccinia striiformis f. sp. tritici), die über die Jahre in Abhängigkeit von Witterung und Befallsdruck sehr unterschiedlich stark auftraten. Der Fungizid-Behandlungsindex als Maß für die Intensität des Pflanzenschutzes, zeigte in der Phase 1 mit einem Wert von 0,8 (situationsbezogene Pflanzenschutzmittelanwendung (100%) und 0,4 (50% der situationsbezogenen Anwendung) im Mittel der Jahre einen signifikanten Unterschied zwischen den zu prüfenden Strategien, der auf die strikte Reduktion der Pflanzenschutzmittelanwendungen um 50% zurückzuführen war. Die Umstellung des Versuches in Phase 2 und 3 führte in der IPS-Strategie zu einem Fungizid-Behandlungsindex von 1,2 und 1,1 sowie in der GfP-Strategie zu Werten von 1,7 und 1,9, die sich im Vergleich der Strategien als nicht signifikant verschieden erwiesen. Beim Vergleich der Erträge ergab sich in nur zwei (2001, 2006) der 23 Jahre ein signifikanter Unterschied zwischen den Strategien. Im Vergleich der fungizidbehandelten Varianten zu den unbehandelten Kontrollen innerhalb der Strategien war in der GfP-Strategie in nur vier Jahren ein signifikanter Unterschied ersichtlich, bei der IPS-Strategie in nur einem Jahr. Fungizidanwendungen wären retrospektiv betrachtet häufig nicht erforderlich gewesen. Entsprechend der Erträge und Fungizid-Behandlungsindizes, war auch der fungizidkostenfreie Erlös gemittelt über die sechs Jahre der Phase 3 nicht signifikant verschieden. Die Untersetzung der Strategien GfP und IPS reichte bislang nicht aus, um einen deutlichen Unterschied zwischen diesen zu zeigen, was letztlich auf die schon geringen Fungizid-Behandlungsindizes in der Strategie GfP zurückzuführen ist, die in allen Phasen unter denen der regionalen Praxis lagen und auf die teils gut wirksamen Resistenzen der ausgewählten Sorten. Trotz der häufigen Überschreitungen der Bekämpfungsrichtwerte und der daraus resultierenden Fungizidanwendungen, war der weitere Krankheitsverlauf oft mäßig bis gering. Deutliche Ertragsunterschiede zeigten sich lediglich in Jahren mit hohem Befallsdruck und günstigen Witterungsbedingungen für den Infektionsverlauf.In order to develop concepts for integrated plant protection, a field trial of the Julius Kühn-Institute was set up in Dahnsdorf (Brandenburg) in 1995 and various long-term field trials were carried out. Within the framework of the largest and oldest on-site long-term field trial “Comparison of Strategies for Environmentally Friendly Plant Protection”, this paper examines the effects of a 50% reduction strategy in phase 1 (1997 to 2007) and a consistent implementation of integrated plant protection (IPS) in phase 2 (2008 to 2013) and modified in phase 3 (2014 to 2019) compared to a practical strategy (GfP), with regard to situation-specific plant protection against fungal pathogens in winter wheat. While in the first two phases of the trial (1997 to 2013) identical varieties were grown in the strategies, in phase 3 an extension was made to include the variety component. The most frequently occurring diseases were leaf blotch (Zymoseptoria tritici, Septoria nodorum), leaf rust (Puccinia triticina) and yellow rust (Puccinia striiformis f. sp. tritici), which occurred with very different intensity over the years depending on weather and disease pressure. The fungicide treatment frequency index, as a measure of the intensity of plant protection, showed a value of 0.8 (situation-related plant protection product application (100%) and 0.4 (50% of situation-related application) in phase 1 on average over the years. This was a significant difference between the strategies to be tested, which was due to the strict reduction of plant protection product applications by 50%. The change of the trial in phase 2 and 3 resulted in a fungicide treatment frequency index of 1.2 and 1.1 in the IPS strategy and 1.7 and 1.9 in the GfP strategy, which proved to be not significantly different. When comparing the yields, there was a significant difference between the strategies in only two (2001, 2006) of the 23 years. Also in comparison with the untreated controls, a significant difference was evident in only four years in the GfP strategy, and in only one year in the IPS strategy. Fungicide applications would often not have been necessary retrospectively. In line with the yields and fungicide treatment frequency indices, the net profit averaged over the six years of phase 3 was also not significantly different. Thus, the differentiation of the GfP and IPS strategies was not sufficient to show a clear difference between them so far, which is ultimately due to the already low fungicide treatment frequency indices in the GfP strategy, which were below those of regional practice in all phases, and to the effective resistances of the selected varieties. Despite the frequent exceeding of the control thresholds and the resulting fungicide applications, the disease progress was often moderate to low. Clear yield differences are only evident in years with high disease pressure and favourable weather conditions for infection