(2) Organische zuren en thymol en biotechnische imkermethoden: Varroabestrijding op stand

In het bijenvolk heeft de mijt een kwetsbare positie op de bijen (de foretische mijt) en een relatief veilige plaats in het broed (de reproducerende mijt). Dit laatste is relatief want door de voorkeur voor darrenbroed is deze veilige plaats toch minder veilig voor de mijt. In een broedloos volk zijn alle mijten foretisch en dit is dan ook een ideale situatie om de mijt te bestrijden

Honey bee collected pollen for botanical identification via its2 metabarcoding: a comparison of preservation methods for citizen science

DNA metabarcoding is emerging as a powerful method for botanical identification of bee-collected pollen, allowing analysis of hundreds of samples in a single high-throughput sequencing run, therefore offering unprecedented scale in citizen science projects. Biases in metabarcoding can be introduced at any stage of sample processing and preservation is the first step of the pipeline. Hence, it is important to test whether the pollen preservation method influences metabarcoding performance. While in metabarcoding studies pollen has typically been preserved at −20°C, this is not the best method to be applied by citizen scientists. Here, we compared the freezing method (FRZ) with ethanol (EtOH), silica gel (SG) and room temperature (RT) in 87 pollen samples collected from hives in Austria and Denmark.AQ acknowledges the PhD scholarship (DFA/BD/5155/2020) funded by FCT. This study was funded by INSIGNIA “Environmental monitoring of pesticides use through honey bees” (SANTE/E4/SI2.788418-SI2.788452).info:eu-repo/semantics/publishedVersio

Managed honey bee colony losses in Canada, China, Europe, Israel and Turkey, for the winters of 2008-9 and 1009-10

In 2008 the COLOSS network was formed by honey bee experts from Europe and the USA. The primary objectives set by this scientific network were to explain and to prevent large scale losses of honey bee (Apis mellifera) colonies. In June 2008 COLOSS obtained four years support from the European Union from COST and was designated as COST Action FA0803 – COLOSS (Prevention of honey bee COlony LOSSes). To enable the comparison of loss data between participating countries, a standardized COLOSS questionnaire was developed. Using this questionnaire information on honey bee losses has been collected over two years. Survey data presented in this study were gathered in 2009 from 12 countries and in 2010 from 24 countries. Mean honey bee losses in Europe varied widely, between 7-22% over the 2008-9 winter and between 7-30% over the 2009-10 winter. An important finding is that for all countries which participated in 2008-9, winter losses in 2009-10 were found to be substantially higher. In 2009-10, winter losses in South East Europe were at such a low level that the factors causing the losses in other parts of Europe were absent, or at a level which did not affect colony survival. The five provinces of China, which were included in 2009-10, showed very low mean (4%) A. mellifera winter losses. In six Canadian provinces, mean winter losses in 2010 varied between 16-25%, losses in Nova Scotia (40%) being exceptionally high. In most countries and in both monitoring years, hobbyist beekeepers (1-50 colonies) experienced higher losses than practitioners with intermediate beekeeping operations (51-500 colonies). This relationship between scale of beekeeping and extent of losses effect was also observed in 2009-10, but was less pronounced. In Belgium, Italy, the Netherlands and Poland, 2008-9 mean winter losses for beekeepers who reported ‘disappeared’ colonies were significantly higher compared to mean winter losses of beekeepers who did not report ‘disappeared’ colonies. Mean 2008-9 winter losses for those beekeepers in the Netherlands who reported symptoms similar to “Colony Collapse Disorder” (CCD), namely: 1. no dead bees in or surrounding the hive while; 2. capped brood was present, were significantly higher than mean winter losses for those beekeepers who reported ‘disappeared’ colonies without the presence of capped brood in the empty hives. In the winter of 2009-10 in the majority of participating countries, beekeepers who reported ‘disappeared’ colonies experienced higher winter losses compared with beekeepers, who experienced winter losses but did not report ‘disappeared’ colonies

Honey bee colony winter loss rates for 35 countries participating in the COLOSS survey for winter 2018–2019, and the effects of a new queen on the risk of colony winter loss

peer-reviewedThis article presents managed honey bee colony loss rates over winter 2018/19 resulting from using the standardised COLOSS questionnaire in 35 countries (31 in Europe). In total, 28,629 beekeepers supplying valid loss data wintered 738,233 colonies, and reported 29,912 (4.1%, 95% confidence interval (CI) 4.0–4.1%) colonies with unsolvable queen problems 79,146 (10.7%, 95% CI 10.5–10.9%) dead colonies after winter and 13,895 colonies (1.9%, 95% CI 1.8–2.0%) lost through natural disaster. This gave an overall colony winter loss rate of 16.7% (95% CI 16.4–16.9%), varying greatly between countries, from 5.8% to 32. 0%. We modelled the risk of loss as a dead/empty colony or from unresolvable queen problems and found that, overall, larger beekeeping operations with more than 150 colonies experienced significantly lower losses (p<0.001), consistent with earlier studies. Additionally, beekeepers included in this survey who did not migrate their colonies at least once in 2018 had significantly lower losses than those migrating (p<0.001). The percentage of new queens from 2018 in wintered colonies was also examined as a potential risk factor. The percentage of colonies going into winter with a new queen was estimated as 55.0% over all countries. Higher percentages of young queens corresponded to lower overall losses (excluding losses from natural disaster), but also lower losses from unresolvable queen problems, and lower losses from winter mortality (p<0.001). Detailed results for each country and overall are given in a table, and a map shows relative risks of winter loss at regional level

Spatial clusters of Varroa destructor control strategies in Europe

Publication history: Accepted - 18 May 2022; Published online - 29 June 2022Beekeepers have various options to control the parasitic mite Varroa destructor in honey bee colonies, but no empirical data are available on the methods they apply in practice. We surveyed 28,409 beekeepers maintaining 507,641 colonies in 30 European countries concerning Varroa control methods. The set of 19 diferent Varroa diagnosis and control measures was taken from the annual COLOSS questionnaire on honey bee colony losses. The most frequent activities were monitoring of Varroa infestations, drone brood removal, various oxalic acid applications and formic acid applications. Correspondence analysis and hierarchical clustering on principal components showed that six Varroa control options (not necessarily the most used ones) signifcantly contribute to defning three distinctive clusters of countries in terms of Varroa control in Europe. Cluster I (eight Western European countries) is characterized by use of amitraz strips. Cluster II comprises 15 countries from Scandinavia, the Baltics, and Central-Southern Europe. This cluster is characterized by long-term formic acid treatments. Cluster III is characterized by dominant usage of amitraz fumigation and formed by seven Eastern European countries. The median number of diferent treatments applied per beekeeper was lowest in cluster III. Based on estimation of colony numbers in included countries, we extrapolated the proportions of colonies treated with diferent methods in Europe. This suggests that circa 62% of colonies in Europe are treated with amitraz, followed by oxalic acid for the next largest percentage of colonies. We discuss possible factors determining the choice of Varroa control measures in the diferent clustersOpen access funding provided by University of Graz. The authors have no relevant financial or non-financial interests to disclose. COLOSS and its supporters had no influence on the study design or the decision to publish

Honey bee colony loss rates in 37 countries using the COLOSS survey for winter 2019–2020: the combined effects of operation size, migration and queen replacement

Publication history: Accepted - 12 July 2022; Published online - 6 September 2022.This article presents managed honey bee colony loss rates over winter 2019/20 resulting from using the standardised COLOSS questionnaire in 37 countries. Six countries were from outside Europe, including, for the first time in this series of articles, New Zealand. The 30,491 beekeepers outside New Zealand reported 4.5% of colonies with unsolvable queen problems, 11.1% of colonies dead after winter and 2.6% lost through natural disaster. This gave an overall colony winter loss rate of 18.1%, higher than in the previous year. The winter loss rates varied greatly between countries, from 7.4% to 36.5%. 3216 beekeepers from New Zealand managing 297,345 colonies reported 10.5% losses for their 2019 winter (six months earlier than for other, Northern Hemisphere, countries). We modelled the risk of loss as a dead/empty colony or from unresolvable queen problems, for all countries except New Zealand. Overall, larger beekeeping operations with more than 50 colonies experienced significantly lower losses (p<0.001). Migration was also highly significant (p<0.001), with lower loss rates for operations migrating their colonies in the previous season. A higher proportion of new queens reduced the risk of colony winter loss (p<0.001), suggesting that more queen replacement is better. All three factors, operation size, migration and proportion of young queens, were also included in a multivariable main effects quasi-binomial GLM and all three remained highly significant (p<0.001). Detailed results for each country and overall are given in a table, and a map shows relative risks of winter loss at the regional level.Dutch Ministry of Agriculture, Nature and Food Quality (BO-43-011.03-005); Republic of Serbia, MPNTR-RS, through Grant No. III46002; Slovakia the project "Sustainable smart farming systems taking into account the future challenges 313011W112"; Slovenian Research Program P1-0164; Danish Beekeepers Association for their funding and support of the international LimeSurvey platform used by many participating countries; “Zukunft Biene 2” (grant number 101295/2) in Austria; University of Graz for open access

Honey bee colony loss rates in 37 countries using the COLOSS survey for winter 2019–2020 : the combined effects of operation size, migration and queen replacement

This article presents managed honey bee colony loss rates over winter 2019/20 resulting from using the standardised COLOSS questionnaire in 37 countries. Six countries were from outside Europe, including, for the first time in this series of articles, New Zealand. The 30,491 beekeepers outside New Zealand reported 4.5% of colonies with unsolvable queen problems, 11.1% of colonies dead after winter and 2.6% lost through natural disaster. This gave an overall colony winter loss rate of 18.1%, higher than in the previous year. The winter loss rates varied greatly between countries, from 7.4% to 36.5%. 3216 beekeepers from New Zealand managing 297,345 colonies reported 10.5% losses for their 2019 winter (six months earlier than for other, Northern Hemisphere, countries). We modelled the risk of loss as a dead/empty colony or from unresolvable queen problems, for all countries except New Zealand. Overall, larger beekeeping operations with more than 50 colonies experienced significantly lower losses (

Honey bee collected pollen for botanical identification via its2 metabarcoding: a comparison of preservation methods for citizen science

While classical palynology has been the method of choice to assess botanical diversity of bee-collected pollen for multiple purposes, DNA metabarcoding is emerging as a powerful alternative being able to achieve high taxonomic identification accuracy. Moreover,DNA metabarcoding allows analysis of hundreds of samples in a single high-throughput sequencing run, therefore offering unprecedented scale in citizen science projects. Biases in metabarcoding can be introduced at any stage of sample processing and preservation is at the forefront of the pipeline. Hence, it is important to test how sample preservation influences quality and quantitative performance of pollen metabarcoding. While inmetabarcoding studies pollen has typically been preserved at −20°C (FRZ), this is not the best method to be applied by citizen scientists.info:eu-repo/semantics/publishedVersio

Outcome of the workshop

On 4th and 5th of February 2014, 18 researchers from 13 countries attended the workshop in Graz, Austria. The workshop was supported by COLOSS, University of Graz, the Dean of the Faculty of Science and the Austrian Research Association. An authorized questionnaire that was drafted before the workshop was finalised during the workshop after necessary extended discussion. The questionnaire will be published on the COLOSS website to make it available to all interested countries. Deadlines and important dates for the 2014 monitoring and submission of data were established. The use of additional databases (meteorological and land use) which could be relevant for better understanding of the past and future loss data collected using the COLOSS questionnaire was explored, with input from specialists from other fields. So far only winter losses have been considered, however in southern countries summer losses appear to be more important. This issue was discussed and a decision was taken to further explore summer losses in specific southern areas ideally using a randomized approach. The general feeling was that the monitoring group currently acts as an European entity which attracts other countries, but which may require to develop a stronger European profile. For COLOSS, it would be a good initiative for similar entities to be developed independently in other continents by honey bee researchers based in those continents. Further exploration of specific requirements and conditions is needed. The issue of compliance with the EU regulations on data protection was discussed for future implementation. A jointly authored publication on winter 2012-2013 colony losses which is in press and soon to appear in the Journal of Apicultural Research was welcomed by the participants of the workshop and would be accompanied by an IBRA press release to publicise this article

Outcome of the workshop : C.S.I. Pollen – training the national agents in Graz

On 6th and 7th of February 2014, 26 researchers attended a workshop in Graz, Austria. The workshop was supported by COLOSS, the University of Graz and the Dean of the Faculty of Science. Pollen is the only source of proteins for honey bee colonies and is needed to feed brood, for organ development of adult honey bees and build-up of reserves to become long lived winter bees. All participants welcomed the initiative and agreed that the pollen nutrition of honey bees is of great importance for colony health and survival, and needs to be adequately studied. A means to study the biodiversity of pollen in the supply of honey bee colonies on a large scale is through the involvement of beekeepers as Citizen Scientists (C.S.). As beekeepers cannot perform full palynological analyses, we have developed a simple estimation of pollen diversity according to the colour of corbicular pollen pellets. This allows us to obtain information on a large number of samples, but also requires standardized protocols in all participating countries. National coordinators from the following countries agreed to conduct a common investigation in 2014 and 2015 using the protocols developed for C.S.I. Pollen in pilot studies in 2013: National coordinators of the following countries were present: Austria, Croatia , Denmark, England, France, Ireland, Italy, Netherlands, Norway, Romania, Scotland, Slovenia, Spain, Sweden, Switzerland and Wales. We will re-evaluate the protocols after one year, and also invite other countries to join. As a second step, samples collected by the beekeeper can be analysed to connect pollen diversity derived from colour differentiation of pollen pellets, to the number of plant species identified by palynological analysis. The funding for this second level investigation is to be left to the national coordinators. Traditional melissopalynological methods are not as suitable for the analysis of corbicular pollen pellets compared to honey, so standardized methods for this will be developed. The methods of sub-sampling, storage and transport need to be developed. The first level C.S. Investigations in the different countries will be coordinated and data collected for joint analyses and publication