Non-Apis bees as model organisms in laboratory, semi-field and field experiments

Im Rahmen der Zulassung von Pflanzenschutzmitteln und ihren Wirkstoffen in der EU wurde das Risiko für Bienen bisher anhand der Westlichen Honigbiene (Apis mellifera L.) als Modellorganismus für alle Bienenarten bewertet. In den letzten Jahren wurde kontrovers diskutiert, ob Wildbienenarten in der Risikobewertung ebenfalls berücksichtigt werden sollten, um die bisherigen Daten­anforderungen für Honigbienen zu erweitern. Dies geht damit einher, etablierte, standardisierte Methoden für die Honigbiene an zusätzliche Wildbienenarten anzupassen und zu verstehen, wie diese Arten auf den verschiedenen Testebenen (Labor-, Halbfreiland- und Freilandtests) eingesetzt werden können. In diesem Artikel gehen wir zunächst auf die Bedeutung von Bienen als Testorganismen ein, diskutieren den derzeitigen Stand der Forschung, die für die Methodenentwicklung und das experimentelle Design für das Arbeiten mit Bienen wichtig ist, um abschließend einen Ausblick auf aktuelle Aktivitäten in der Standardisierung von Testmethoden zu geben.As part of the registration process of plant protection products (PPPs) and their active substances in the EU, the risk of PPPs for bees has been assessed so far by using the European honey bee (Apis mellifera L.) as a surrogate species. In the past few years other bee species have been discussed to augment data on honey bees. The addition of bee species in the registration process goes along with adapting test methodologies to new bee species and understand­ing how to use these species at different tiers (laboratory, semi-field and field levels). Here we first discuss the importance of bees as test organisms, outline the current state of research relevant to the methodology and design of experiments with bees and highlight recent activities in the standardization of test procedures

4.9 Exposure by nesting material? – Investigation of potentially suitable methods for higher tier studies with solitary bees

The registration processes and risk assessment of plant protection products (PPPs) on bees resulted in an increasing need for experiments with non-apis pollinators to assess potential side effects of PPPs on this relatively new group of test organisms. Recently, numerous studies have been performed but there is still a wide range of ongoing challenges. One of the challenges is the risk from insecticide exposure to solitary bees (especially at larval stages) by contaminated nesting material (e.g. mud partitions – mason bees). In 2017, an experiment was performed with the horn-faced mason bee Osmia cornuta (Hymenoptera, Megachilidae) under modified field conditions. The aim of the experiment was to develop a suitable test method for higher tier risk assessments with solitary wild bees exposed to treated nesting material. The potential effect of an insect growth regulator (IGR) to bees and their brood was examined. The reproduction capacity and brood termination rate were observed in the study as endpoints. Furt ermore, hatching success and flight activity were recorded as additional information at several occasions.The present results provide no evidence that the exposure has an effect on the development during the larval stages of Osmia cornuta, neither in pollen mass nor in the nesting material.The registration processes and risk assessment of plant protection products (PPPs) on bees resulted in an increasing need for experiments with non-apis pollinators to assess potential side effects of PPPs on this relatively new group of test organisms. Recently, numerous studies have been performed but there is still a wide range of ongoing challenges. One of the challenges is the risk from insecticide exposure to solitary bees (especially at larval stages) by contaminated nesting material (e.g. mud partitions – mason bees). In 2017, an experiment was performed with the horn-faced mason bee Osmia cornuta (Hymenoptera, Megachilidae) under modified field conditions. The aim of the experiment was to develop a suitable test method for higher tier risk assessments with solitary wild bees exposed to treated nesting material. The potential effect of an insect growth regulator (IGR) to bees and their brood was examined. The reproduction capacity and brood termination rate were observed in the study as endpoints. Furt ermore, hatching success and flight activity were recorded as additional information at several occasions.The present results provide no evidence that the exposure has an effect on the development during the larval stages of Osmia cornuta, neither in pollen mass nor in the nesting material

Higher TIER bumble bees and solitary bees recommendations for a semi-field experimental design

The publication of the proposed EFSA risk assessment guidance document of plant protection products for pollinators highlighted that there are no study designs for non-Apis pollinators available. Since no official guidelines exist for semi-field testing at present, protocols were proposed by the ICPPR non-Apis working group and two years of ring-testing were conducted in 2016 and 2017 to develop a general test set-up. The ringtest design was based on the draft EFSA guidance document, OEPP/EPPO Guideline No. 170 and results of discussions regarding testing solitary bees and bumble bees during the meetings of the ICPPR non-Apis workgroup. Ring-tests were conducted with two different test organisms, one representative of a social bumble bee species (Bombus terrestris L; Hymenoptera, Apidae) and one representative of a solitary bee species (Osmia bicornis L; Hymenoptera, Megachilidae). The species are common species in Europe, commercially available and widely used for pollination services. Several laboratories participated in the higher-tier ring tests. 15 semi-field tests were conducted with bumble bees and 16 semi-field tests were done with solitary bees in 2016 and 2017. Two treatment groups were always included in the ringtests: an untreated control (water treated) and the treatment with dimethoate as a toxic reference item (optional other i.e. brood-affecting substances fenoxycarb or diflubenzuron). The toxic reference items were chosen based on their mode of action and long term experience in honey bee testing. A summary of the ringtest results will be given and the recommendations for the two semi-field test designs will be presented.The publication of the proposed EFSA risk assessment guidance document of plant protection products for pollinators highlighted that there are no study designs for non-Apis pollinators available. Since no official guidelines exist for semi-field testing at present, protocols were proposed by the ICPPR non-Apis working group and two years of ring-testing were conducted in 2016 and 2017 to develop a general test set-up. The ringtest design was based on the draft EFSA guidance document, OEPP/EPPO Guideline No. 170 and results of discussions regarding testing solitary bees and bumble bees during the meetings of the ICPPR non-Apis workgroup. Ring-tests were conducted with two different test organisms, one representative of a social bumble bee species (Bombus terrestris L; Hymenoptera, Apidae) and one representative of a solitary bee species (Osmia bicornis L; Hymenoptera, Megachilidae). The species are common species in Europe, commercially available and widely used for pollination services. Several laboratories participated in the higher-tier ring tests. 15 semi-field tests were conducted with bumble bees and 16 semi-field tests were done with solitary bees in 2016 and 2017. Two treatment groups were always included in the ringtests: an untreated control (water treated) and the treatment with dimethoate as a toxic reference item (optional other i.e. brood-affecting substances fenoxycarb or diflubenzuron). The toxic reference items were chosen based on their mode of action and long term experience in honey bee testing. A summary of the ringtest results will be given and the recommendations for the two semi-field test designs will be presented

Risk assessment requires several bee species to address species-specific sensitivity to insecticides at field-realistic concentrations

Abstract In the European registration process, pesticides are currently mainly tested on the honey bee. Since sensitivity data for other bee species are lacking for the majority of xenobiotics, it is unclear if and to which extent this model species can adequately serve as surrogate for all wild bees. Here, we investigated the effects of field-realistic contact exposure to a pyrethroid insecticide, containing lambda-cyhalothrin, on seven bee species (Andrena vaga, Bombus terrestris, Colletes cunicularius, Osmia bicornis, Osmia cornuta, Megachile rotundata, Apis mellifera) with different life history characteristics in a series of laboratory trials over two years. Our results on sensitivity showed significant species-specific responses to the pesticide at a field-realistic application rate (i.e., 7.5 g a.s./ha). Species did not group into distinct classes of high and low mortality. Bumble bee and mason bee survival was the least affected by the insecticide, and M. rotundata survival was the most affected with all individuals dead 48 h after application. Apis mellifera showed medium mortality compared to the other bee species. Most sublethal effects, i.e. behavioral abnormalities, were observed within the first hours after application. In some of the solitary species, for example O. bicornis and A. vaga, a higher percentage of individuals performed some abnormal behavior for longer until the end of the observation period. While individual bee weight explained some of the observed mortality patterns, differences are likely linked to additional ecological, phylogenetic or toxicogenomic parameters as well. Our results support the idea that honey bee data can be substitute for some bee species’ sensitivity and may justify the usage of safety factors. To adequately cover more sensitive species, a larger set of bee species should be considered for risk assessment

Hochschulbezogene Lehr-Lern-Forschung als Basis für die Lehrprofessionalisierung

Jütte W, Walber M, Lobe C. Hochschulbezogene Lehr-Lern-Forschung als Basis für die Lehrprofessionalisierung. In: Brahm T, Jenert T, Euler D, eds. Pädagogische Hochschulentwicklung: von der Programmatik zur Implementierung. Wiesbaden: Springer VS; 2015: 83-99

Results of 2-Year Ring Testing of a Semifield Study Design to Investigate Potential Impacts of Plant Protection Products on the Solitary Bees Osmia Bicornis and Osmia Cornuta and a Proposal for a Suitable Test Design

There are various differences in size, behavior, and life history traits of non-Apis bee species compared with honey bees (Apis mellifera; Linnaeus, 1758). Currently, the risk assessment for bees in the international and national process of authorizing plant protection products has been based on honey bee data as a surrogate organism for non-Apis bees. To evaluate the feasibility of a semifield tunnel test for Osmia bicornis (Linnaeus, 1758) and Osmia cornuta (Latreille, 1805), a protocol was developed by the non-Apis working group of the International Commission for Plant-Pollinator Relationships, consisting of experts from authorities, academia, and industry. A total of 25 studies were performed over a 2-yr period testing a replicated control against a replicated positive control using either a dimethoate or diflubenzuron treatment. Studies were regarded to be valid, if ≥30% of released females were found to occupy the nesting units in the night/morning before the application (establishment). Thirteen studies were regarded to be valid and were analyzed further. Parameters analyzed were nest occupation, flight activity, cell production (total and per female), cocoon production (total and per female), emergence success, sex ratio, and mean weight of females and males. Dimethoate was a reliable positive control at the tested rate of 75 g a.i./ha, once >30% females had established, displaying acute effects such as reduction in flight activity, increase in adult mortality (shown by nest occupation), and reproduction ability of the females (total cell and cocoon production). On the other hand, no effects on larval and pupal development were observed. The growth regulator diflubenzuron had statistically significant effects on brood development, causing mortality of eggs and larvae at a rate of approximately 200 g a.i./ha, whereas fenoxycarb did not cause any significant effects at the tested rates of 300 and 600 g a.i./ha. In conclusion, the ring-test protocol proved to be adequate once the study comprised a well-established population of female Osmia bees, and the results improved in the second year as the laboratories increased their experience with the test organism. It is noted that the success of a study strongly depends on the experience of the experimenter, the crop quality, the quality of the cocoons, and the weather conditions. Based on these finding, recommendations for a semifield study design with Osmia spp. are proposed. Environ Toxicol Chem 2020;00:1–15.</p