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

4.14 Developing methods for field experiments using commercially reared bumblebee colonies – initial colony strength and experimental duration as influential factors

Semi-field and field experiments with commercially used bumblebees (e.g. Bombus terrestris) gain more and more importance for both ecological studies and trials on potential side effects of plant protection products. However, standardized, replicable experimental methods are lacking so far and need further development. For example, initial strength of bumblebee colonies may vary across experiments but may be a key factor in successful colony development under field conditions. Trial duration and termination may impact results on total reproductive output (e.g. number of newly produced queens). In this study commercially reared bumblebee colonies of different initial strengths (number of worker bees) were placed along the field margin of each of six field sites. Each site was nested within one of two seasons and planted with one of two arable crops (Brassica napus and Phacelia tanacetifolia). Each colony was spaced approx. 50 m apart from the next colony, and its development was monitored once a week. While the development of half of the colonies was terminated at the first sighting of newly emerging queens within the nesting area, the other half of the colonies was left to develop further until the end of their natural colony cycle. Newly emerging queens were kept within the colonies using queen excluders. Colonies of different initial strengths showed very similar developmental patterns with medium and large colonies peaking slightly earlier than small colonies. Results may help to develop optimal parameters for standardized field tests.Semi-field and field experiments with commercially used bumblebees (e.g. Bombus terrestris) gain more and more importance for both ecological studies and trials on potential side effects of plant protection products. However, standardized, replicable experimental methods are lacking so far and need further development. For example, initial strength of bumblebee colonies may vary across experiments but may be a key factor in successful colony development under field conditions. Trial duration and termination may impact results on total reproductive output (e.g. number of newly produced queens). In this study commercially reared bumblebee colonies of different initial strengths (number of worker bees) were placed along the field margin of each of six field sites. Each site was nested within one of two seasons and planted with one of two arable crops (Brassica napus and Phacelia tanacetifolia). Each colony was spaced approx. 50 m apart from the next colony, and its development was monitored once a week. While the development of half of the colonies was terminated at the first sighting of newly emerging queens within the nesting area, the other half of the colonies was left to develop further until the end of their natural colony cycle. Newly emerging queens were kept within the colonies using queen excluders. Colonies of different initial strengths showed very similar developmental patterns with medium and large colonies peaking slightly earlier than small colonies. Results may help to develop optimal parameters for standardized field tests

Evaluating the feasibility of using the red mason bee (Osmia bicornis L.) in different experimental setups

Background: Evaluating hazards of pesticides to beneficial insects has become very important for the assessment and registration of pesticides. Test methods for honeybees are well established in the laboratory, under semi-field and field conditions. However, experiences in using other pollinators as model species are limited. Here we present results of various experiments on the red mason bee (Osmia bicornis L.), a solitary, commercially used bee species. The aim was to compare methodologies, to assess test parameters, and to evaluate the feasibility of using O. bicornis in late season, when this bee species would have already finished its life cycle under natural conditions. Results: Hatching times and hatching rates varied depending on temperature and season. Provisioning and reproduction of O. bicornis were very variable, weather-dependent and not always reliably reproducible between seasons. They were higher in early than in late season in the field. In late season cardboard tubes showed greater cell production than wooden boards. Conclusion: O. bicornis is a good study system under semi-field and field conditions: cocoons are easy to handle, and to monitor. Since hatching rate and cell production decreased over time, experiments are most recommended in early to mid season. Cardboard tubes can be used as standardised, inexpensive nesting devices. However, they do not allow continuous observation and pollen sampling, and involve time-consuming handling in the laboratory. Our experiment on nest material was conducted in late season and may not mirror conditions in spring and early summer.Keywords: solitary bees, field experiments, semi-field experiments, reproduction, hatching, nestin

Energy and Charged Particle Flow in 10.8 A GeV/c Au+Au Collisions

Experimental results and a detailed analysis are presented of the transverse energy and charged particle azimuthal distributions measured by the E877 collaboration for different centralities of Au+Au collisions at a beam momentum of 10.8 A GeV/c. The anisotropy of these distributions is studied with respect to the reaction plane reconstructed on an event-by-event basis using the transverse energy distribution measured by calorimeters. Results are corrected for the reaction plane resolution. For semicentral events we observe directed flow signals of up to ten percent. We observe a stronger anisotropy for slow charged particles. For both the charged particle and transverse energy distributions we observe a small but non zero elliptic anisotropy with the major axis pointing into the reaction plane. Combining the information on transverse energy and charged particle flow we obtain information on the flow of nucleons and pions. The data are compared to event generators and the need to introduce a mean field or nucleon-nucleon potential is discussed.Comment: RevTex, 25 pages, 13 figures included as one Postscript file, submitted to Phys. Rev.

Neonicotinoids and bees: A large scale field study investigating residues and effects on honeybees, bumblebees and solitary bees in oilseed rape grown from clothianidin-treated seed

In 2013, the European Food Safety Authority (EFSA) has highlighted several data gaps regarding the exposure and risk of pesticides to honeybees, bumblebees and solitary bees, including the risks from exposure to contaminated nectar and pollen. This study aims to contribute data, results and conclusions to obtain more information on exposure and risks of flowering oilseed rape seed treated with the neonicotinoid clothianidin, to pollinators. Semi-field and field trials were conducted at five different locations across Germany, using the Western honeybee (Apis mellifera L.), the buff-tailed bumblebee (Bombus terrestris L.) and the red mason bee (Osmia bicornis L.) as study organisms.Highest amounts of clothianidin residues were measured in single samples of mud cell walls (7.2 μg kg-1) and pollen (5.9 μg kg-1) from solitary bee nests. Residues in nectar from honey sacs, honeybee combs and bumblebee nests (2.2, 2.9, and 3.0 μg kg-1 respectively) showed no clear differences in the amount of residues, neither did residues in pollen (1.5, 1.8, and 1.3 μg kg-1 respectively). These results suggest differences in the risk profiles of those three bee species. Keywords: clothianidin, residues, honeybees, bumblebees, solitary bees, field, semi-fiel

Two-pion correlations in Au+Au collisions at 10.8 GeV/c per nucleon

Two-particle correlation functions for positive and negative pions have been measured in Au+Au collisions at 10.8~GeV/c per nucleon. The data were analyzed using one- and three-dimensional correlation functions. From the results of the three-dimensional fit the phase space density of pions was calculated. It is consistent with local thermal equilibrium.Comment: 5 pages RevTeX (including 3 Figures

Proton and Pion Production in Au+Au Collisions at 10.8A GeV/c

We present proton and pion tranverse momentum spectra and rapidity distributions for Au+Au collisions at 10.8A GeV/c. The proton spectra exhibit collective transverse flow effects. Evidence of the influence of the Coulomb interaction from the fireball is found in the pion transverse momentum spectra. The data are compared with the predictions of the RQMD event generator.Comment: plain tex (revtex), 24 pages Submitted to Phys. Rev.

Directed flow of antiprotons in Au+Au collisions at AGS

Directed flow of antiprotons is studied in Au+Au collisions at a beam momentum of 11.5A GeV/c. It is shown that antiproton directed flow is anti-correlated to proton flow. The measured transverse momentum dependence of the antiproton flow is compared with predictions of the RQMD event generator.Comment: 16 pages, 6 figure

Use of a Western blot technique for the serodiagnosis of glanders

<p>Abstract</p> <p>Background</p> <p>The in vivo diagnosis of glanders relies on the highly sensitive complement fixation test (CFT). Frequently observed false positive results are troublesome for veterinary authorities and cause financial losses to animal owners. Consequently, there is an urgent need to develop a test with high specificity. Hence, a Western blot assay making use of a partly purified lipopolysaccaride (LPS) containing antigen of three <it>Burkholderia mallei </it>strains was developed. The test was validated investigating a comprehensive set of positive and negative sera obtained from horses and mules from endemic and non endemic areas.</p> <p>Results</p> <p>The developed Western blot assay showed a markedly higher diagnostic specificity when compared to the prescribed CFT and therefore can be used as a confirmatory test. However, the CFT remains the test of choice for routine testing of glanders due to its high sensitivity, its feasibility using standard laboratory equipment and its worldwide distribution in diagnostic laboratories.</p> <p>Conclusions</p> <p>The CFT should be amended by the newly validated Western blot to increase the positive likelihood ratio of glanders serodiagnosis in non endemic areas or areas with low glanders prevalence. Its use for international trade of horses and mules should be implemented by the OIE.</p