Vincent Dietemann

Agroscope · Swiss Bee Research Center

- Deutsche Version des Tätigkeitsberichts des Zentrums für Bienenforschung für die Jahre 2022 und 2023 - German version of the Bee Research Centre's activity report for 2022 and 2023

Riconoscere le malattie delle api e attuare le adeguate misure di prevenzione e di lotta sono i presupposti fondamentali per una buona pratica apicola e il segreto per colonie d'api in piena salute. Le malattie non solo si diffondono rapidamente all'interno degli apiari a causa dei contatti fisici e della trofallassi (scambio di cibo tra le api) e...

Bienenkrankheiten erkennen und dazu die angezeigten Bekämpfungs- und Vorbeugemassnahmen zur Hand zu haben, sind Grundvoraussetzungen für eine gute imkerliche Praxis und damit der Schlüssel für gesunde Bienenvölker. Seuchen- und Kranheitsprävention haben bei den Bienen einen noch wichtigeren Stellenwert als bei anderen Nutztieren. Durch die komplexe...

Reconnaître les maladies des abeilles et connaître les méthodes de lutte et de prévention efficaces sont des conditions sine qua non pour garantir la santé des abeilles et pour une bonne pratique apicole. Les maladies se propagent non seulement très rapidement à l’intérieur des ruches en raison des contacts physiques entre ouvrières et de la tropha...

Honey bees play an essential role in modern agriculture as farm animals and crop pollinators, and they contribute to one third of our diet. Over the last few decades, managed honey bees have faced large-scale losses worldwide. Various causes include the spread of pathogens and parasites, habitat loss and loss of forage, pesticide use, and climate c...

We sequenced the genomes of recently discovered Paenibacillus melissococcoides (CCOS 2000) and of the type strains of closely related P. thiaminolyticus (DSM 7262) and P. dendritiformis (LMG 21716). The three genomes set the basis to unambiguous diagnostic of these honey bee associated Paenibacillus bacteria.

A novel, facultatively anaerobic, Gram-stain-positive, motile, endospore-forming bacterium of the genus Paenibacillus , designated strain 2.1 T , was isolated from a colony of Apis mellifera affected by European foulbrood disease in Switzerland. The rod-shaped cells of strain 2.1 T were 2.2–6.5 µm long and 0.7–1.1 µm wide. Colonies of strain 2.1 T...

Honey bees, Apis mellifera, of European origin are major pollinators of crops and wild flora. Their endemic and exported populations are threatened by a variety of abiotic and biotic factors. Among the latter, the ectoparasitic mite Varroa destructor is the most important single cause behind colony mortality. The selection of mite resistance in hon...

The homogenization of agricultural landscapes has led to a decrease in pollinator diversity and abundance. In response to this decline, farmers have implemented agroecological measures, which, in meadows, aim at providing more floral resources. These measures are the availability of unmown floral strips, delayed mowing, and discouraging the use of...

European foulbrood (EFB) is a honey bee brood disease caused by the bacterium Melissococcus plutonius. Large-scale EFB outbreaks have been reported in several countries in recent decades, which entail costly sanitation measures of affected apiaries to restrict the spread of this contagious pathogen. To mitigate its impact, a better understanding of...

Melissococcus plutonius is a pathogenic bacterium affecting immature stages of the western honey bee (Apis mellifera) and leads to European foulbrood (EFB) disease. Despite EFB outbreaks increasing in frequency in several countries in recent decades, there is little knowledge on the epidemiology of M. plutonius or on the defence mechanisms of honey...

To defend themselves against pathogenic microorganisms, honey bees resort to social immunity mechanisms, such as the secretion of antibiotic compounds in the jelly they feed to their larvae. Whereas the bactericidal activity of jelly fed to queen larvae is well studied, little is known about the bioactivity of compositionally different jelly fed to...

Nuovi metodi di analisi per i residui nella cera d’api, trattamento contro gli acari della varroa, migliore valutazione dei rischi legati ai pesticidi per le api, perdite invernali e tanto altro ancora – Ecco una panoramica dei progetti di ricerca in corso.

Nouvelle méthode d'analyse des résidus dans la cire d'abeilles, traitement contre l'acarien varroa, amélioration de l'évaluation du risque lié aux pesticides pour les abeilles, pertes hivernales, etc. – voici un aperçu des projets de recherche en cours.

Neue Analysemethode für Rückstände im Bienenwachs, Behandlung der Varroa-Krankheit, Winterverluste, die Bekämpfung der Wachsmotte mit Essigsäure und mehr – ein Einblick in die laufenden Forschungsprojekte.

Trans-generational immune priming involves the transfer of immunological experience, acquired by the parents after exposure to pathogens, to protect their progeny against infections by these pathogens. Such natural mechanisms could be exploited to prevent disease expression in economically important insects, such as the honey bee. This mechanism oc...

Introduction Host shifts of parasites can have devastating effects on novel hosts. One remarkable example is that of the ectoparasitic mite Varroa destructor, which has shifted hosts from Eastern honey bees (Apis cerana) to Western honey bees (Apis mellifera) and posed a major global threat to apiculture and wild honey bees. Objectives and methods...

The invasive parasitic mite, Varroa destructor (Anderson and Trueman), is the major biotic threat to the survival of European honey bees, Apis mellifera L. To improve colony survival against V. destructor, the selection of resistant lineages against this parasite is considered a sustainable solution. Among selected traits, mite fertility and fecund...

The ectoparasitic mite Varroa destructor affects honey bee colony health and survival negatively, thus compelling beekeepers to treat their colonies every year. A broadly used mite control regimen is based on two organic molecules: formic and oxalic acids. To ensure optimal efficiency, several applications of these acids at pre-defined time points...

A diverse supply of pollen is an important factor for honey bee health, but information about the pollen diversity available to colonies at the landscape scale is largely missing. In this COLOSS study, beekeeper citizen scientists sampled and analyzed the diversity of pollen collected by honey bee colonies. As a simple measure of diversity, beekeep...

The BEEBOOK project arose from discussions at early COLOSS (Prevention of Honey Bee COlony LOSSes) meetings. The vision was, and still is, to develop a definitive inventory of standard techniques and methods in honey bee research to ensure that studies performed by different laboratories around the world would be directly comparable. The manual, ti...

In this article published in the beekeeping journal "Revue suisse d'apiculture", we present the work carried out during the year 2020 at the Agroscope Bee Research Centre in Switzerland.

In a globalized world, parasites are often brought in contact with new potential hosts. When parasites successfully shift host, severe diseases can emerge at a large cost to society. However, the evolutionary processes leading to successful shifts are rarely understood, hindering risk assessment, prevention, or mitigation of their effects. Here, we...

Publication in the beekeeping journal "Schweizerische Bienen-Zeitung".

Citizen Science contributes significantly to the conservation of biodiversity, but its application to honey bee research has remained minimal. Even though certain European honey bee (Apis mellifera) populations are known to naturally survive Varroa destructor infestations, it is unclear how widespread or common such populations are. Such colonies a...

Comparative studies of genetic diversity and population structure can shed light on the ecological and evolutionary factors governing host-parasite interactions. Even though invasive parasites are considered of major biological importance, little is known about their adaptative potential when infesting the new hosts. Here, the genetic diversificati...

Co-evolution is a major driving force shaping the outcome of host-parasite interactions over time. After host shifts, the lack of co-evolution can have a drastic impact on novel host populations. Nevertheless, it is known that Western honey bee (Apismellifera) populations can cope with host-shifted ectoparasitic mites (Varroa destructor) by means o...

Parasite host shifts can impose a high selective pressure on novel hosts. Even though the coevolved systems can reveal fundamental aspects of host-parasite interactions, research often focuses on the new host-parasite relationships. This holds true for two ectoparasitic mite species, Varroa destructor and Varroa jacobsonii, which have shifted hosts...

Background In spite of the implementation of control strategies in honey bee ( Apis mellifera ) keeping, the invasive parasitic mite Varroa destructor remains one of the main causes of colony losses in numerous countries. Therefore, this parasite represents a serious threat to beekeeping and agro-ecosystems that benefit from the pollination service...

The socio-economic impacts of COVID-19 on society have yet to be truly revealed; there is no doubt that the pandemic has severely affected the daily lives of most of humanity. It is to be expected that the research activities of scientists could be impacted to varying degrees, but no data exist on how COVID-19 has affected research specifically. He...

Honey is an important food for man and has been used as a natural sweetener since ancient times. It is a viscous and aromatic product made by honey bees using the nectar of flowers or honeydew. Honey is composed of a complex mix- ture of carbohydrates and other substances such as organic acids, amino acids, proteins, minerals, vitamins, lipids, aro...

The COLOSS BEEBOOK project arose from discussions at meetings of the COLOSS (Prevention of Honey Bee COlony LOSSes; www.coloss.org) association, which was established in 2008 to explore all possible reasons for honey bee colony losses (Williams et al., 2012). Those unfamiliar with the concept of the COLOSS BEEBOOK are welcome to consult the introdu...

Melissococcus plutonius is a bacterial pathogen that causes epidemic outbreaks of European foulbrood (EFB) in honey bee populations. The pathogenicity of a bacterium depends on its virulence, and understanding the mechanisms influencing virulence may allow for improved disease control and containment. Using a standardized in vitro assay, we demonst...

Despite the implementation of control strategies, the invasive parasitic mite Varroa destructor remains one of the principal causes of honey bee (Apis mellifera) colony losses in numerous countries. For this reason, the parasite represents a serious threat to beekeeping and to agro-ecosystems that benefit from the pollination services provided by h...

The strength of honey bee (Apis mellifera) colonies is vital for successful beekeeping. This parameter influences the amount of honey produced (Farrar1937) and the number of foragers available to perform pollination services (Harbo1986; Szabo and Lefkovitch 1989; Liebig1993; Keller et al. 2005) and reflects its health and fitness (Imdorf et al.2010...

Des travaux récents montrent une diminution de l’abondance et de la diversité des pollinisateurs sauvages, ainsi qu’une augmentation de la mortalité des abeilles domestiques. Tous ces pollinisateurs font partie intégrante de la biodiversité et jouent un rôle essentiel dans la production de certaines cultures et dans la reproduction des plantes sauv...

Host shifts of parasites are often causing devastating effects in the new hosts. The Varroa genus is known for a lineage of Varroa destructor that shifted to the Western honey bee, Apis mellifera , with disastrous effects on wild populations and the beekeeping industry. Despite this, the biology of Varroa spp. remains poorly understood in its nativ...

The Western honeybee, Apis mellifera, is the most important managed pollinator globally and has recently experienced unsustainably high colony losses. Synergistic interactions among stressors are believed to be primarily responsible. However, despite clear evidence of strong effect on honeybee longevity of widely-employed neonicotinoid insecticides...

Riconoscere le malattie delle api e attuare le adeguate misure di prevenzione e di lotta sono i presupposti fondamentali per una buona pratica apicola e il segreto per colonie d’api in piena salute. Le malattie non solo si diffondono rapidamente all’interno degli apiari a causa dei contatti fisici e della trofallassi (scambio di cibo tra le api) e...

The COLOSS (Prevention of Honey Bee Colony Losses) network was founded in 2008 as a consequence of the heavy and frequent losses of honey bee colonies experienced in many regions of the world (Neumann & Carreck, 2010). The network has many accomplishments, with the COLOSS BEEBOOK being among those. The COLOSS BEEBOOK was developed to provide honey...

Krankheitserreger und Schädlinge sind zu einem grossen Teil für die in den vergangenen Jahren beobachteten hohen Verluste von Bienenvölker verantwortlich. Viele verschiedene Organismen suchen in den Kolonien Unterschlupf und können dort Krankheiten auslösen. Dazu gehören beispielsweise Pilze, Bakterien, Viren und Milben. Sie können die Adulttiere e...

Reconnaître les maladies des abeilles et connaître les méthodes de lutte et de prévention efficaces sont des conditions sine qua non pour garantir la santé des abeilles et pour une bonne pratique apicole. Les maladies se propagent non seulement très rapidement à l’intérieur des ruches en raison des contacts physiques entre ouvrières et de la tropha...

The ectoparasitic mite Varroa destructor Anderson and Trueman (Acarina: Varroidae) shifted host from Eastern honeybees Apis cerana Fabricius (Hymenoptera: Apidae) to Western honeybees Apis mellifera Linnaeus (Hymenoptera: Apidae) with disastrous consequences globally. The high genetic diversity of V. destructor and abundant opportunities for cross-...

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

DNA methylation is a reversible epigenetic modifcation that alters gene expression without altering the nucleotide sequence. Epigenetic modifcations have been suggested as crucial mediators between social interactions and gene expression in mammals. However, little is known about the role of DNA methylation in the life cycle of social invertebrates...

The ectoparasitic mite, Varroa destructor, shifted host from the eastern honeybee, Apis cerana, to the western honeybee, Apis mellifera. Whereas the original host survives infestations by this parasite, they are lethal to colonies of its new host. Here, we investigated a population of A. cerana naturally infested by the V. destructor Korea haplotyp...

Agroscope-Forscher untersuchten die Bedeutung der Bestäubungsleistung von Honig-und Wildbienen für die Schweiz. Dabei zeigte sich, dass zusätzlich zu den Obst-und Beerenflächen, die stark von der Bestäubung durch Bienen abhängig sind, auf 14 % der Ackerfläche Kulturen angebaut werden, welche auch von der Bestäubung durch Insekten profitieren. Der d...

In einigen Ackerkulturen, vor allem aber auch bei Obst und Beeren, sind Ertrag und Quali- tät der Ernte von der Bestäubung durch In- sekten abhängig. Gemäss weltweiten Schätzungen tragen Honig- und Wildbienen gleich viel zu dieser Wertschöpfung bei.Systemati- sche Untersuchungen für die Schweiz gibt es dazu aber nicht. Mit Hilfe von Daten zur Fläch...

Dans certaines grandes cultures, mais aussi et surtout dans certaines cultures de fruits et de baies, le rendement et la qualité de la récolte dépendent de la pollinisation par les insectes. Selon des estimations mondiales, les abeilles domestiques et sauvages contribuent à parts égales à cette valeur ajoutée. Jusqu’à présent, il n’existait cependa...

For some field crops, and especially fruits and berries, harvested yield quantity and quality are dependent on pollination by insects. According to global estimates, honeybees and wild bees contribute equally to this ecosystem service, although there are no systematic studies for Switzerland. Now, for the first time, and with the help of data on th...

Di conseguenza, per permettere una lotta efficace contro la varroa, il Centro di ricerche apicole di Liebefeld consiglia vivamente di trattare le colonie con l’acido ossalico in assenza di covata invernale. È possibile garantire questo tipo di trattamento aspettando fino al momento in cui le colonie non hanno più covata (naturalmente) oppure elimin...

Das zweite Jahr der europäischen Studie «C. S. I. Pollen» zur Pollendiversität ist vollendet und liefert wiederum interessante Daten über die von Honigbienen angetroffene Pollenvielfalt in der Schweiz, die wir in diesem Bericht präsentieren möchten.

Um effizienter gegen die Varroa vorzugehen, empfiehlt das Zentrum für Bienenforschung Liebefeld dringend, die Völker mit Oxalsäure zu behandeln, wenn keine Winterbrut vorhanden ist. Dies kann erfolgen, indem man entweder zuwartet, bis das Volk auf natürliche Weise keine Winterbrut mehr aufweist oder durch Vernichtung der Winterbrut. Letzteres ist z...

Organisms' lifespans are modulated by both genetic and environmental factors. The lifespan of eusocial insects is determined by features of the division of labor, which itself is influenced by social regulatory mechanisms. In the honey bee, Apis mellifera, the presence of brood and of old workers carrying out foraging tasks are important social dri...

Dank noch nie gesehener Röntgenbilder von Honigbienenwaben konnte unser Forschungsteam (Agroscope – Zentrum für Bienenforschung und Institut für Bienengesundheit der Universität Bern) beobachten, wie Honig produziert wird. Mittels Computertomografie haben wir die Zuckerkonzentration in den Wachszellen gemessen, ohne die sensitiven Mechanismen des B...

The poor health status of the Western honey bee, Apis mellifera, compared to its Eastern counterpart, Apis cerana, is remarkable. This has been attributed to lower pathogen prevalence in A. cerana colonies and to their ability to survive infestations with the ectoparasitic mite, Varroa destructor. These properties have been linked to an enhanced re...

Honey bees, Apis species, obtain carbohydrates from nectar and honeydew. These resources are ripened into honey in wax cells that are capped for long-term storage. These stores are used to overcome dearth periods when foraging is not possible. Despite the economic and ecological importance of honey, little is known about the processes of its produc...

Sugar concentration (left y-axis) and filling level (right y-axis) over time in ten individual cells per colony. Each row corresponds to a colony and shows a representative subsample of filling and ripening dynamics. The first five cells of each line represent early provisioned cells that contained solutions already at day 1 (some were relocated at...

Comparison of cell filling level and content concentration between consecutive days in early provisioned and eventually capped cells. Significant P—values (< 0.05) from the robust-ranked method (nparLD) are indicated with *. (DOCX)

Results from the two-sample tests for equality of proportions between consecutive days. The test was performed for each pattern category and for the three colonies separately. Decrease or increase of proportions between the two days are indicated with < and >, respectively. Significant P—values (< 0.05) are indicated with *. (DOCX)

Test comb appearance in colony 2. Scans were performed at A) day 1, B) day 2, C) day 5, D) day 8, E) day 12 after feeding. Cell density patterns observed on each day are depicted by icons on the right side of each picture. Note 1) the increasing density and number of filled cells; 2) the changing shape of the area of nectar containing cells due to...