| 1. |
- Gekière, Antoine, et al.
(författare)
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Poison or Potion : Effects of Sunflower Phenolamides on Bumble Bees and Their Gut Parasite
- 2022
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Ingår i: Biology. - : MDPI AG. - 2079-7737. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- Specific floral resources may help bees to face environmental challenges such as parasite infection, as recently shown for sunflower pollen. Whereas this pollen diet is known to be unsuitable for the larval development of bumble bees, it has been shown to reduce the load of a trypanosomatid parasite (Crithidia bombi) in the bumble bee gut. Recent studies suggested it could be due to phenolamides, a group of compounds commonly found in flowering plants. We, therefore, decided to assess separately the impacts of sunflower pollen and its phenolamides on a bumble bee and its gut parasite. We fed Crithidia-infected and -uninfected microcolonies of Bombus terrestris either with a diet of willow pollen (control), a diet of sunflower pollen (natural diet) or a diet of willow pollen supplemented with sunflower phenolamides (supplemented diet). We measured several parameters at both microcolony (i.e., food collection, parasite load, brood development and stress responses) and individual (i.e., fat body content and phenotypic variation) levels. As expected, the natural diet had detrimental effects on bumble bees but surprisingly, we did not observe any reduction in parasite load, probably because of bee species-specific outcomes. The supplemented diet also induced detrimental effects but by contrast to our a priori hypothesis, it led to an increase in parasite load in infected microcolonies. We hypothesised that it could be due to physiological distress or gut microbiota alteration induced by phenolamide bioactivities. We further challenged the definition of medicinal effects and questioned the way to assess them in controlled conditions, underlining the necessity to clearly define the experimental framework in this research field.
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| 2. |
- Gérard, Maxence, et al.
(författare)
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Impact of crop exposure and agricultural intensification on the phenotypic variation of bees
- 2022
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Ingår i: Agriculture, Ecosystems & Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 338
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Tidskriftsartikel (refereegranskat)abstract
- In a context of rapid global change, understanding how environmental stressors can impact phenotypic variation, and which phenotypic traits are predominantly affected can be particularly relevant. Indeed, potential phenotypic modifications could affect the functionality of traits from taxa that are in decline but that are keystone species in many ecosystems. In this study, we assessed the impact of environmental drivers and agricultural intensification on two crucial pollinator species: the honeybee (Apis mellifera) and the buff-tailed bumblebee (Bombus terrestris). Among eight countries representing four major European biogeographical regions [i.e., Boreal (Sweden and Estonia), Atlantic (Ireland and United Kingdom), Continental (Germany and Switzerland) and Mediterranean (Spain and Italy)] and two type of crops (i.e., apple orchards and oilseed rape) we assessed how landscape structure, latitude and pesticide management could impact their wing morphology. Two sampling sessions were conducted: the first one when the hives/nests were settled on the field (T0) and a second sampling session after the potential effect of agricultural intensification (T1). Using a dataset of more than 7238 wings, we measured the wing size, shape and asymmetry. We observed that, in several countries, a shift in most of the morphological traits occurred between T0 and T1. When focusing on the drivers of phenotypic variation in T1, the levels of significance for some potential drivers were sometimes high, while most of the variation remained unexplained. The latitude and, more rarely, grassland cover were found to partly explain the wing modifications. In light of these results, we conclude that phenotypic shifts can occur in a very short period, after encountering new field conditions. Further studies should be conducted to better understand which alternative drivers could explain morphological changes in the agro-ecosystem after crop exposition, as well as the potential consequences of these changes on foraging performance or pollination efficiency.
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| 3. |
- Hodge, Simon, et al.
(författare)
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Design and Planning of a Transdisciplinary Investigation into Farmland Pollinators : Rationale, Co-Design, and Lessons Learned
- 2022
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Ingår i: Sustainability (Switzerland). - : MDPI AG. - 2071-1050. ; 14:17
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Tidskriftsartikel (refereegranskat)abstract
- To provide a complete portrayal of the multiple factors negatively impacting insects in agricultural landscapes it is necessary to assess the concurrent incidence, magnitude, and interactions among multiple stressors over substantial biogeographical scales. Trans-national ecological field investigations with wide-ranging stakeholders typically encounter numerous challenges during the design planning stages, not least that the scientific soundness of a spatially replicated study design must account for the substantial geographic and climatic variation among distant sites. ‘PoshBee’ (Pan-European assessment, monitoring, and mitigation of Stressors on the Health of Bees) is a multi-partner transdisciplinary agroecological project established to investigate the suite of stressors typically encountered by pollinating insects in European agricultural landscapes. To do this, PoshBee established a network of 128 study sites across eight European countries and collected over 50 measurements and samples relating to the nutritional, toxicological, pathogenic, and landscape components of the bees’ environment. This paper describes the development process, rationale, and end-result of each aspect of the of the PoshBee field investigation. We describe the main issues and challenges encountered during the design stages and highlight a number of actions or processes that may benefit other multi-partner research consortia planning similar large-scale studies. It was soon identified that in a multi-component study design process, the development of interaction and communication networks involving all collaborators and stakeholders requires considerable time and resources. It was also necessary at each planning stage to be mindful of the needs and objectives of all stakeholders and partners, and further challenges inevitably arose when practical limitations, such as time restrictions and labour constraints, were superimposed upon prototype study designs. To promote clarity for all stakeholders, for each sub-component of the study, there should be a clear record of the rationale and reasoning that outlines how the final design transpired, what compromises were made, and how the requirements of different stakeholders were accomplished. Ultimately, multi-national agroecological field studies such as PoshBee benefit greatly from the involvement of diverse stakeholders and partners, ranging from field ecologists, project managers, policy legislators, mathematical modelers, and farmer organisations. While the execution of the study highlighted the advantages and benefits of large-scale transdisciplinary projects, the long planning period emphasized the need to formally describe a design framework that could facilitate the design process of future multi-partner collaborations.
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