In animal and human health care, imaging techniques such as radiology, echography and scanning by magnetic resonance imaging (MRI) have hugely improved the prognosis and diagnosis of diseases by veterinarians and doctors. Imaging mass spectrometry (IMS) provides unique opportunities for analysing tissues, organs, and even whole organisms at an unprecedented level of detail. We have adapted IMS for use in honey bees, enabling us to produce images of drugs/chemicals, metabolites, sugars, lipids (fats) & protein distributions across organs. This is visualised in scans of protein distribution in the body of honey bees that are infected, or not, by a fungal parasite, the causative agent of nosemosis.

-As Confucius, the Chinese Philosopher, said “a picture is worth a thousand words”. Just imagine a general practitioner facing a broken leg without the image provided by a radiogram

-The unique IMS technique bridges the gap between visual examination & targeted molecular analyses

-A new frontier to discover protein signatures of an organ & a body in response to stressors

-A new generation of mass spectrometers are compatible for high-throughput screening of the spatial distribution of proteins, lipids, metabolites and drugs in any type of tissue or the entire body of a honey bee

-It is well known that nosemosis impacts gut morphology and physiology. When applied to a honey bee facing nosemosis, IMS also highlighted the nosemosis’ impact on the flight muscles located in the thorax, on the gland secreting the Royalisin protein, and on the immune response triggered by Nosema (presence of the Apidaecin protein) in bee blood

-A versatile technique applicable to other pollinators

Sources: doi:10.1002/pmic.202100224, www.theses.fr/2020GRALV009

PoshBee’s long-term objective is to support healthy bee populations & sustainable beekeeping, in which successful cooperation between diverse stakeholder groups is crucial. Here, effective science communication plays a huge role, bridging the gap between the groups’ areas of expertise. To achieve that in PoshBee, we often receive feedback from our stakeholder groups, ensuring bi-directional communication, for example via surveys or dedicated sessions. Based on stakeholder feedback, we created a list of good practices to help practitioners in their cooperation with different stakeholders with potentially diverging expertise.

● Plain language: avoid jargon - use figures of speech instead. Illustrative figures like metaphors or examples provide a human dimension to the otherwise abstract information. They help the audience understand the new concept by connecting it to a concept already familiar to them. Additionally, visual communication like graphics accompanying the text makes information easier to retain and increases its accessibility as it can reach people of all literacy levels.

● Tailoring: take into account who your audience is. To develop messages which capture people’s interest, it is essential to first identify & understand their values and needs. You can then use this understanding to determine the content they receive, how it is framed, who presents it & where. In this way, you make sure your message is indeed relevant.

● Positive arguments: emphasise solutions and benefits, not problems & losses. Make sure to acknowledge uncertainty and scepticism, but also demonstrate established knowledge. This ensures you address the barriers stakeholders face while providing them with solutions, which make change seem easy.

PoshBee is a complex project requiring communication with multiple stakeholder categories with diverse knowledge, meaning we often have to transfer information from one category to the other, which involves overcoming certain barriers. Specifically, one barrier that seems to be relevant across all stakeholder groups’ communication is sharing uncertainty. Uncertainty is an inherent part of knowledge, yet, with increasing doubt about scientific authority, we are reluctant to openly share it. However, not adequately communicating uncertainty can lead to a loss of trust from your audience. To help practitioners communicate their uncertainty to stakeholders, we present a list of PoshBee-tested tips:

● Establish the object of uncertainty: does it concern the underlying hypothesis or the claimed facts? Defining the scope of uncertainty will help you address it.

● Be transparent and specific: elusive expressions like “could be higher or lower” decrease the audience’s trust. Being explicit about what you do not know avoids casting a shadow of mistrust over the entire message, making your audience think none of the information can be trusted. It is also important to explain jargon, avoiding wrong interpretations.

● Avoid repeating qualifiers: studies found that reading the same qualifier several times increases its strength in the audience’s perception (Mislavsky & Gaertig, 2020), causing unwarranted certainty.

● Know how much science is enough: uncertainty can arise if your audience is flooded with the technicalities of scientific details. On the other hand, they may be inadequately informed if not presented with important uncertainties in the field, which create nuances on a certain topic.

Source: dx.doi.org/10.2139/ssrn.3454796

We conducted a range of laboratory experiments on individual bumble bees where we exposed them to one of three agrochemicals (sulfoxaflor, an insecticide; azoxystrobin, a fungicide; glyphosate, a herbicide) and/or Crithidia bombi (a common bumble bee gut parasite). We assessed impacts on survival, food consumption, parasite load and learning. We conclude that, under the experimental conditions we used, there are no meaningful interactions between these agrochemicals and the common bumble bee parasite. This suggests that current laboratory-based aspects of risk assessment of these agrochemicals does not require integration of parasitism as an additional stressor. However, we note that other conditions, and other, more virulent parasites, may still be a source of interactive impacts on bee health.

We also exposed ~6-8 week old bumble bee colonies to sulfoxaflor and/or the parasite Crithidia bombi and examined impacts on colony development and pollination services. The results suggest that field realistic exposure of bumble bee colonies 6-8 weeks post-founding to sulfoxaflor, and/or the parasite, is not harmful to their development, nor does it impact pollination services. This develops our understanding of the safe use of sulfoxaflor. While sulfoxaflor has now been banned for outside use in the EU, our research does not suggest further changes to its registration in or outside the EU are currently justified. However, further studies of interactions with other pathogens are needed before general statements can be made.

Beekeepers are confronted with unsustainable high losses of managed Western honey bee, Apis mellifera, colonies. There is consensus that such losses are closely associated with ectoparasitic mites, Varroa destructor, which are potent vectors of several viruses. However, these mites may also interact with other stressors, e.g. acaricides (e.g., coumaphos) or widely used neonicotinoid-like insecticides (e.g., sulfoxaflor). However, the interface between mites and these chemicals is poorly understood. Here, we show that field-realistic concentrations of sulfoxaflor can increase the reproduction of V. destructor. Furthermore, in combination with coumaphos, sulfoxaflor can also cause higher mortality in bee larvae. Our data support that neonicotinoid (-like) insecticides can not only have negative consequences for bees, but also seem to have positive effects on mites.

Implementations/recommendations: The positive correlation between sulfoxaflor and mite reproduction is concerning and should be considered when assessing the risk of agrochemicals to bees. The combined effects of sulfoxaflor and coumaphos are not fully understood and require further research. However, our data suggest that such possible interactions have to be integrated in the risk assessment process. Beekeepers should consider the possible negative side effects of their interventions and keep in mind that acaricides might also have undesired side effects on bees either alone and/or in combination with other agrochemicals.

In 2019, PoshBee partners undertook a field survey across 8 European countries (CH, DE, EE, ES, IE, IT, SE, UK) to assess the exposure of bees to multiple stressors (chemical products, pathogens, and nutritional deficiency). Honey bees, bumble bees and mason bees were deployed on oilseed rape fields and apple orchards (128 sites in total). For each site, the agricultural practices, environmental parameters and landscape features were assessed.

High levels of pesticide residues were found in bees and bee products. Nearly all beebread samples contained at least one pesticide, mostly fungicides. Approximately half of nectar samples were contaminated with pesticides, fungicides being often identified. More than two thirds of beeswax contained at least one pesticide. Potassium, magnesium and aluminium were quantified at high concentrations in honeybees and in beebread from the three bee species. The main pathogens (viruses, microsporidia, and bacteria) were detected in honey bees. In contrast, only few of them were detected in bumble bees and mason bees. In terms of nutrition, protein content in beebread did not vary at country and species level. In contrast, there was a high variation of lipid content at country and species level.

As a result, we recommend that:

• Scientists: Assess several types of stressors at multiple developmental stages and matrices when investigating pollinator health.

• Beekeepers: Thoroughly examine colonies for early detection of diseases to reduce damage on honeybee populations.

• Farmers: Pollinator health is also important for you. Adjust your plant protection strategy to reduce pesticide use.

The availability of nutritive resources is a key factor affecting honeybee health. However, a reduction in floral resource abundance and diversity is generally observed in agro-ecosystems, along with widespread exposure to pesticides. We therefore studied whether the availability and quality of pollen diets could affect the susceptibility of honeybees to pesticides. For that purpose, we evaluated the toxicity of azoxystrobin (fungicide) and sulfoxaflor (insecticide) in honeybees provided with pollen diets of differing qualities. We found that both pollen availability and most importantly its quality (bees rarely facing a total lack of pollen) can improve their ability to eliminate pesticides and reduce the mortality risk that they cause.

This nutritional modulation may increase variability in pesticide sensitivity in the field, given that the abundance and composition of honeybee pollen diets can be highly variable across landscapes and seasons. Consequently, the availability of floral resources should be considered in honeybee pesticide risk assessment. Finally, this study provides another strong argument for the restoration of floral resource abundance and diversity in such habitats.



Link to the study: https://royalsocietypublishing.org/doi/10.1098/rsos.210818

In this review, we highlighted the gap between new evidence of pesticide toxicity in honeybees and regulatory toxicological bioassays recommended by regulatory test guidelines. In order to fill this gap and better assess the threat of pesticides to honeybees, we emphasized the need to complement current endpoints (essentially based on LD50 - dose at which 50% of the individuals die) with sublethal endpoints. We focus on behavioral and reproductive endpoints, which have received increasing interest due to their ecological relevance and the emergence of new technologies made in their recording. Moreover, pesticides can have low-dose effects on these endpoints. So, this review reported the biological interest and methodological measurements of such endpoints and discussed their possible use in pesticide risk assessment. It appears that homing flights and reproduction have great potential for pesticide risk assessment, mainly due to their ecological relevance. If exploratory research studies in ecotoxicology have paved the way toward a better understanding of pesticide toxicity in honeybees, the next objective will then be to translate the most relevant behavioral and reproductive endpoints into regulatory test methods. This will require more comparative studies and improving their ecological relevance. This latter goal may be facilitated by the use of population dynamics models for scaling up the consequences of adverse behavioral and reproductive effects from individuals to colonies.

Link to the review: https://hal.inrae.fr/hal-03170652