1
|
Gekière A, Vanderplanck M, Hettiarachchi A, Semay I, Gerbaux P, Michez D, Joossens M, Vandamme P. A case study of the diet-microbiota-parasite interplay in bumble bees. J Appl Microbiol 2023; 134:lxad303. [PMID: 38066692 DOI: 10.1093/jambio/lxad303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/05/2023] [Accepted: 12/07/2023] [Indexed: 12/20/2023]
Abstract
AIMS Diets and parasites influence the gut bacterial symbionts of bumble bees, but potential interactive effects remain overlooked. The main objective of this study was to assess the isolated and interactive effects of sunflower pollen, its phenolamides, and the widespread trypanosomatid Crithidia sp. on the gut bacterial symbionts of Bombus terrestris males. METHODS AND RESULTS Bumble bee males emerged in microcolonies fed on either (i) willow pollen (control), (ii) sunflower pollen, or (iii) willow pollen spiked with phenolamide extracts from sunflower pollen. These microcolonies were infected by Crithidia sp. or were pathogen-free. Using 16S rRNA amplicon sequencing (V3-V4 region), we observed a significant alteration of the beta diversity but not of the alpha diversity in the gut microbial communities of males fed on sunflower pollen compared to males fed on control pollen. Similarly, infection by the gut parasite Crithidia sp. altered the beta diversity but not the alpha diversity in the gut microbial communities of males, irrespective of the diet. By contrast, we did not observe any significant alteration of the beta or alpha diversity in the gut microbial communities of males fed on phenolamide-enriched pollen compared to males fed on control pollen. Changes in the beta diversity indicate significant dissimilarities of the bacterial taxa between the treatment groups, while the lack of difference in alpha diversity demonstrates no significant changes within each treatment group. CONCLUSIONS Bumble bees harbour consistent gut microbiota worldwide, but our results suggest that the gut bacterial communities of bumble bees are somewhat shaped by their diets and gut parasites as well as by the interaction of these two factors. This study confirms that bumble bees are suitable biological surrogates to assess the effect of diet and parasite infections on gut microbial communities.
Collapse
Affiliation(s)
- Antoine Gekière
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, Mons, Belgium, 20 Place du Parc, 7000 Mons, Belgium
| | - Maryse Vanderplanck
- CEFE, CNRS, Univ Montpellier, EPHE, IRD, Montpellier, France, 1919 Route de Mende, 34293 Montpellier, France
| | - Amanda Hettiarachchi
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, 35 K.L. Ledeganckstraat, 9000 Ghent, Belgium
| | - Irène Semay
- Organic Synthesis and Mass Spectrometry Laboratory, Research Institute for Biosciences, University of Mons, Mons, Belgium, 20 Place du Parc, 7000 Mons, Belgium
| | - Pascal Gerbaux
- Organic Synthesis and Mass Spectrometry Laboratory, Research Institute for Biosciences, University of Mons, Mons, Belgium, 20 Place du Parc, 7000 Mons, Belgium
| | - Denis Michez
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, Mons, Belgium, 20 Place du Parc, 7000 Mons, Belgium
| | - Marie Joossens
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, 35 K.L. Ledeganckstraat, 9000 Ghent, Belgium
| | - Peter Vandamme
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, 35 K.L. Ledeganckstraat, 9000 Ghent, Belgium
| |
Collapse
|
2
|
Hettiarachchi A, Cnockaert M, Joossens M, Gekière A, Meeus I, Vereecken NJ, Michez D, Smagghe G, Vandamme P. The wild solitary bees Andrena vaga, Anthophora plumipes, Colletes cunicularius, and Osmia cornuta microbiota are host specific and dominated by endosymbionts and environmental microorganisms. Microb Ecol 2023; 86:3013-3026. [PMID: 37794084 DOI: 10.1007/s00248-023-02304-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 09/19/2023] [Indexed: 10/06/2023]
Abstract
We characterized the microbial communities of the crop, midgut, hindgut, and ovaries of the wild solitary bees Andrena vaga, Anthophora plumipes, Colletes cunicularius, and Osmia cornuta through 16S rRNA gene and ITS2 amplicon sequencing and a large-scale isolation campaign. The bacterial communities of these bees were dominated by endosymbionts of the genera Wolbachia and Spiroplasma. Bacterial and yeast genera representing the remaining predominant taxa were linked to an environmental origin. While only a single sampling site was examined for Andrena vaga, Anthophora plumipes, and Colletes cunicularius, and two sampling sites for Osmia cornuta, the microbiota appeared to be host specific: bacterial, but not fungal, communities generally differed between the analyzed bee species, gut compartments and ovaries. This may suggest a selective process determined by floral and host traits. Many of the gut symbionts identified in the present study are characterized by metabolic versatility. Whether they exert similar functionalities within the bee gut and thus functional redundancy remains to be elucidated.
Collapse
Affiliation(s)
- Amanda Hettiarachchi
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Margo Cnockaert
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Marie Joossens
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Antoine Gekière
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, Place du parc 20, 7000, Mons, Belgium
| | - Ivan Meeus
- Laboratory of Agrozoology, Department of Plants of Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Gent, Belgium
| | - Nicolas J Vereecken
- Agroecology Lab, Université libre de Bruxelles (ULB), Boulevard du Triomphe CP 264/02, 1050, Brussels, Belgium
| | - Denis Michez
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, Place du parc 20, 7000, Mons, Belgium
| | - Guy Smagghe
- Laboratory of Agrozoology, Department of Plants of Crops, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Gent, Belgium
| | - Peter Vandamme
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium.
| |
Collapse
|
3
|
Willcox BK, Potts SG, Brown MJF, Alix A, Al Naggar Y, Chauzat MP, Costa C, Gekière A, Hartfield C, Hatjina F, Knapp JL, Martínez-López V, Maus C, Metodiev T, Nazzi F, Osterman J, Raimets R, Strobl V, Van Oystaeyen A, Wintermantel D, Yovcheva N, Senapathi D. Emerging threats and opportunities to managed bee species in European agricultural systems: a horizon scan. Sci Rep 2023; 13:18099. [PMID: 37872212 PMCID: PMC10593766 DOI: 10.1038/s41598-023-45279-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/18/2023] [Indexed: 10/25/2023] Open
Abstract
Managed bee species provide essential pollination services that contribute to food security worldwide. However, managed bees face a diverse array of threats and anticipating these, and potential opportunities to reduce risks, is essential for the sustainable management of pollination services. We conducted a horizon scanning exercise with 20 experts from across Europe to identify emerging threats and opportunities for managed bees in European agricultural systems. An initial 63 issues were identified, and this was shortlisted to 21 issues through the horizon scanning process. These ranged from local landscape-level management to geopolitical issues on a continental and global scale across seven broad themes-Pesticides & pollutants, Technology, Management practices, Predators & parasites, Environmental stressors, Crop modification, and Political & trade influences. While we conducted this horizon scan within a European context, the opportunities and threats identified will likely be relevant to other regions. A renewed research and policy focus, especially on the highest-ranking issues, is required to maximise the value of these opportunities and mitigate threats to maintain sustainable and healthy managed bee pollinators within agricultural systems.
Collapse
Affiliation(s)
- Bryony K Willcox
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, RG6 6AR, UK.
| | - Simon G Potts
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, RG6 6AR, UK
| | - Mark J F Brown
- Department of Biological Sciences, Royal Holloway University of London, Egham, UK
| | - Anne Alix
- Corteva Agriscience, Regulatory and Stewardship Europe, Middle East and Africa, Abingdon, UK
| | - Yahya Al Naggar
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120, Halle (Saale), Germany
- Zoology Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt
- Unit of Bee Research and Honey Production, Faculty of Science, King Khalid University, P.O. Box 9004, 61413, Abha, Saudi Arabia
| | - Marie-Pierre Chauzat
- ANSES, Sophia Antipolis Laboratory, Unit of Honey Bee Pathology, 06902, Sophia Antipolis, France
| | - Cecilia Costa
- CREA Research Centre for Agriculture and Environment, 40128, Bologna, Italy
| | - Antoine Gekière
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Chris Hartfield
- National Farmers' Union, Agriculture House, Stoneleigh Park, Stoneleigh, Warwickshire, CV8 2TZ, UK
| | - Fani Hatjina
- Department of Apiculture, Institute of Animal Science, ELGO 'DIMITRA', 63200, Nea Moudania, Greece
| | - Jessica L Knapp
- Department of Botany, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
- Department of Biology, Lund University, Lund, Sweden
| | - Vicente Martínez-López
- Department of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
- Department of Zoology and Physical Anthropology, Faculty of Veterinary, University of Murcia, 30100, Murcia, Spain
| | | | | | - Francesco Nazzi
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, Università degli Studi di Udine, Udine, Italy
- National Biodiversity Future Center, Palermo, Italy
| | - Julia Osterman
- Nature Conservation and Landscape Ecology, University of Freiburg, Tennenbacher Str. 4, 79106, Freiburg, Germany
- Gothenburg Global Biodiversity Centre, Gothenburg, Sweden
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Risto Raimets
- Department of Plant Protection, Estonian University of Life Sciences, 51014, Tartu, Estonia
| | - Verena Strobl
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | | | - Dimitry Wintermantel
- Nature Conservation and Landscape Ecology, University of Freiburg, Tennenbacher Str. 4, 79106, Freiburg, Germany
| | | | - Deepa Senapathi
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, RG6 6AR, UK
| |
Collapse
|
4
|
Gekière A, Vanderplanck M, Michez D. Trace metals with heavy consequences on bees: A comprehensive review. Sci Total Environ 2023; 895:165084. [PMID: 37379929 DOI: 10.1016/j.scitotenv.2023.165084] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023]
Abstract
The pervasiveness of human imprint on Earth is alarming and most animal species, including bees (Hymenoptera: Apoidea: Anthophila), must cope with several stressors. Recently, exposure to trace metals and metalloids (TMM) has drawn attention and has been suggested as a threat for bee populations. In this review, we aimed at bringing together all the studies (n = 59), both in laboratories and in natura, that assessed the effects of TMM on bees. After a brief comment on semantics, we listed the potential routes of exposure to soluble and insoluble (i.e. nanoparticle) TMM, and the threat posed by metallophyte plants. Then, we reviewed the studies that addressed whether bees could detect and avoid TMM in their environment, as well as the ways bee detoxify these xenobiotics. Afterwards, we listed the impacts TMM have on bees at the community, individual, physiological, histological and microbial levels. We discussed around the interspecific variations among bees, as well as around the simultaneous exposure to TMM. Finally, we highlighted that bees are likely exposed to TMM in combination or with other stressors, such as pesticides and parasites. Overall, we showed that most studies focussed on the domesticated western honey bee and mainly addressed lethal effects. Because TMM are widespread in the environment and have been shown to result in detrimental consequences, evaluating their lethal and sublethal effects on bees, including non-Apis species, warrants further investigations.
Collapse
Affiliation(s)
- Antoine Gekière
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, 20 Place du Parc, 7000 Mons, Belgium.
| | - Maryse Vanderplanck
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 Route de Mende, 34090 Montpellier, France.
| | - Denis Michez
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, 20 Place du Parc, 7000 Mons, Belgium.
| |
Collapse
|
5
|
Semay I, Lemaur V, Gekière A, Vanderplanck M, Duez P, Michez D, Gerbaux P. Evaluation of Tandem Mass Spectrometry Experiments in the Negative Ionization Mode for Phenolamide Regioisomer Characterization. J Nat Prod 2023; 86:1274-1283. [PMID: 37133415 DOI: 10.1021/acs.jnatprod.3c00047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Phenolamides are abundant specialized metabolites found in nature and consist of hydroxycinnamic acids mono- or polyconjugated with polyamines. Their participation in flower development is well-documented, and their presence in pollen raises the question of their role in pollen/pollinator interactions. The structural characterization of phenolamides is complicated by the presence of positional isomers and stereoisomers. Liquid chromatography coupled to tandem mass spectrometry in the positive ionization mode is becoming very popular in phenolamide structural characterization. However, collision-induced transamidation processes that cause the swapping of side chains have been detected, making it difficult to distinguish regioisomers with this technique. In the present report, we explore the dissociation processes undergone by the [M - H]- ions of spermidine-based phenolamides as model compounds. We describe two original competitive dissociation routes, namely, the phenolate and imidate pathways, to account for the observed fragmentation reactions undergone by collisional activated standard phenolamide anions. Whereas the phenolate pathway is regioselective at the central position for spermidine, the imidate pathway, requiring a deprotonated amide, only occurs at the extremities. Tandem mass spectrometry experiments on negatively charged phenolamide ions may then outperform their positive ionization mode counterparts for the distinction between phenolamide regioisomers and globally for the identification of phenolamides in natural extracts.
Collapse
Affiliation(s)
- Irène Semay
- Organic Synthesis and Mass Spectrometry Laboratory (S2MOs), Research Institute for Biosciences, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium
| | - Vincent Lemaur
- Laboratory for Chemistry of Novel Materials, Materials Research Institute, University of Mons - UMONS, Place du Parc 20, Mons B-7000, Belgium
| | - Antoine Gekière
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium
| | - Maryse Vanderplanck
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium
- CEFE, University of Montpellier, CNRS, EPHE, IRD, 34090 Montpellier, France
| | - Pierre Duez
- Unit of Therapeutic Chemistry and Pharmacognosy, Faculty of Medicine and Pharmacy, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium
| | - Denis Michez
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium
| | - Pascal Gerbaux
- Organic Synthesis and Mass Spectrometry Laboratory (S2MOs), Research Institute for Biosciences, University of Mons - UMONS, 23 Place du Parc, B-7000 Mons, Belgium
| |
Collapse
|
6
|
Vanderplanck M, Marin L, Michez D, Gekière A. Pollen as Bee Medicine: Is Prevention Better than Cure? Biology (Basel) 2023; 12:497. [PMID: 37106698 PMCID: PMC10135463 DOI: 10.3390/biology12040497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/20/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023]
Abstract
To face environmental stressors such as infection, animals may display behavioural plasticity to improve their physiological status through ingestion of specific food. In bees, the significance of medicating pollen may be limited by their ability to exploit it. Until now, studies have focused on the medicinal effects of pollen and nectar after forced-feeding experiments, overlooking spontaneous intake. Here, we explored the medicinal effects of different pollen on Bombus terrestris workers infected by the gut parasite Crithidia bombi. First, we used a forced-feeding experimental design allowing for the distinction between prophylactic and therapeutic effects of pollen, considering host tolerance and resistance. Then, we assessed whether bumble bees favoured medicating resources when infected to demonstrate potential self-medicative behaviour. We found that infected bumble bees had a lower fitness but higher resistance when forced to consume sunflower or heather pollen, and that infection dynamics was more gradual in therapeutic treatments. When given the choice between resources, infected workers did not target medicating pollen, nor did they consume more medicating pollen than uninfected ones. These results emphasize that the access to medicating resources could impede parasite dynamics, but that the cost-benefit trade-off could be detrimental when fitness is highly reduced.
Collapse
Affiliation(s)
| | - Lucie Marin
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium
| | - Denis Michez
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium
| | - Antoine Gekière
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium
| |
Collapse
|
7
|
Abstract
Bumble bees are important pollinators for many temperate crops. Because of the growing demand for food from entomophilous crops, bumble bee colonies are commercially reared and placed in fields or greenhouses to guarantee sufficient pollination services. Besides, commercial colonies are increasingly used in laboratories for various bioassays under controlled conditions. For both usages, bumble bee colonies are commonly provided with sugar solution and honey bee-collected pollen pellets. However, the latter display several disadvantages since they may contain pollutants, pathogens, or toxic phytochemicals. Consequently, companies have developed pollen-free artificial diets to sustain colonies. Such diets are designed to boost worker health in the field, in complement of floral pollen collected by workers outside the colonies, but their suitability in 'closed' systems without access to floral pollen, such as in laboratory bioassays, is arguable. Here, we used microcolonies of the commercially important bumble bee Bombus terrestris L. (Hymenoptera: Apidae) to assess the suitability of five artificial pollen substitutes and three mixed diets. We also assessed the evaporation rate of the different diets as it could impact their suitability. At the end of the bioassays, microcolonies fed the artificial diets showed a reduced offspring development when compared to microcolonies fed natural pollen, which was partly offset by mixing these diets with natural pollen. By contrast, the artificial diets did not have deleterious effects on worker's health. We discuss the potential nutritional and physical causes of artificial diets unsuitability for offspring development and encourage further research to accordingly establish appropriate pollen-free diets for bumble bee breeding.
Collapse
Affiliation(s)
- Antoine Gekière
- Laboratory de Zoology, Research institute for Biosciences, University of Mons, Mons, Belgium
| | - Denis Michez
- Laboratory de Zoology, Research institute for Biosciences, University of Mons, Mons, Belgium
| | | |
Collapse
|
8
|
Gekière A, Semay I, Gérard M, Michez D, Gerbaux P, Vanderplanck M. Poison or Potion: Effects of Sunflower Phenolamides on Bumble Bees and Their Gut Parasite. Biology 2022; 11:biology11040545. [PMID: 35453744 PMCID: PMC9030180 DOI: 10.3390/biology11040545] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 11/29/2022]
Abstract
Simple Summary Bee declines have been reported worldwide, partly due to parasite spread induced by human activities. However, bees may forage on specific floral resources to face parasite infection. Such natural resources are comparable to ‘natural pharmacies’ and may be favoured in bee conservation strategies. Consumption of sunflower pollen, despite being detrimental for larval development, has been recently shown to reduce the load of a widespread bumble bee gut parasite in the common eastern bumble bee. Although the underlying mechanisms remain unknown, it has been suggested that sunflower phenolamides—a family of molecules found in most flowering plants—may be responsible for such a reduction in parasite load. Here, we tested the impacts of sunflower phenolamides on healthy and infected buff-tailed bumble bees. Expectedly, sunflower pollen had harmful consequences on bumble bee development but surprisingly, it did not alter parasite load. By contrast, sunflower phenolamides had milder effects on bumble bee development but unexpectedly increased parasite load. Phenolamide effects may stem from the physiological stress they induced or the gut microbial community alteration they may have triggered. Since biological models and experimental framework differ greatly in related studies tackling plant–bee–parasite interplays, we challenged the definition of medicinal effects and questioned the way to assess them in controlled conditions. 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.
Collapse
Affiliation(s)
- Antoine Gekière
- Laboratoire de Zoologie, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium;
- Correspondence: (A.G.); (M.V.); Tel.: +32-65373436 (A.G.)
| | - Irène Semay
- Organic Synthesis and Mass Spectrometry Laboratory, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium; (I.S.); (P.G.)
| | - Maxence Gérard
- Insect Lab., Division of Functional Morphology, Department of Zoology, Stockholm University, 11418 Stockholm, Sweden;
| | - Denis Michez
- Laboratoire de Zoologie, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium;
| | - Pascal Gerbaux
- Organic Synthesis and Mass Spectrometry Laboratory, Research Institute for Biosciences, University of Mons, 7000 Mons, Belgium; (I.S.); (P.G.)
| | - Maryse Vanderplanck
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 34293 Montpellier, France
- Correspondence: (A.G.); (M.V.); Tel.: +32-65373436 (A.G.)
| |
Collapse
|
9
|
Sculfort O, Gérard M, Gekière A, Nonclercq D, Gerbaux P, Duez P, Vanderplanck M. Specialized Metabolites in Floral Resources: Effects and Detection in Buff-Tailed Bumblebees. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.669352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The selection of appropriate food resources by bees is a critical aspect for the maintenance of their populations, especially in the current context of global change and pollinator decline. Wild bees have a sophisticated ability to forage selectively on specific resources, and can assess the quality of pollen using contact chemosensory perception (taste). While numerous studies have investigated the detection of pollen macronutrients in bees and their impact on bee health and reproductive success, only a few studies have described the gustatory responses of bees toward specialized metabolites. In addition, these studies mostly focused on the response to nectar and neglected pollen, which is the main food resource for both bee imagines and larvae. Whether bees have the ability to detect specialized toxic metabolites in pollen and then rapidly adapt their foraging behavior to avoid them is very little studied. In this study, we tested whether pollen specialized metabolites affect bumblebees at both the micro-colony and individual levels (i.e., bioassays using supplemented pollen), and whether foragers detect these specialized metabolites and potentially display an avoidance behavior (i.e., preference tests using supplemented syrup). Bumblebees were fed with either amygdalin-, scopolamine- or sinigrin-supplemented pollen diets in ratios that mimic 50%, 100%, and 200% of naturally occurring concentrations. We found no effect of these specialized metabolites on resource collection, reproductive success and stress response at the micro-colony level. At the individual level, bumblebees fed on 50%-amygdalin or 50%-scopolamine diets displayed the highest scores for damage to their digestive systems. Interestingly, during the preference tests, the solution with 50%-scopolamine displayed a phagostimulatory activity, whereas solution with 50%-amygdalin had a deterrent effect and could trigger an active avoidance behavior in bumblebees, with a faster proboscis retraction. Our results suggest that regulation of toxin intake is not as well-established and effective as the regulation of nutrient intake in bees. Bees are therefore not equally adapted to all specialized pollen metabolites that they can come into contact with.
Collapse
|