Concordia University
Chercheur(e) invité(e) / Invited researcher candidate
Supervisor: Emma Despland
Colin Favret
Frederic Beaulieu
Start: 2025-09-15

Project

Unseen Threats: Investigating the role of mite communities in bumble bee populations decline
1. Context and issues + general and specific objectives (2 pages max) Bumble bees (Bombus spp.) form an ecologically important group of pollinators found across a wide range of habitats 8. Their large body size, dense hair, and ability to forage in cool or overcast conditions make them highly efficient pollinators of both wild flora and a variety of crops, including those requiring buzz pollination 22. Beyond their role in natural ecosystems, bumble bees have gained increasing attention in agriculture due to their effectiveness in greenhouse and open-field pollination, leading to the development of a global commercial industry for their managed use 12-23. In Québec, this encompasses tomato, blueberry, cranberry and apple productions. Their contribution to both biodiversity and food production underscores the growing need to understand and protect these vital insects. Bumble bee populations are experiencing significant declines globally and in North America, raising concerns about biodiversity and agricultural productivity 2-5. In North America, the situation is particularly alarming, and there are at least 7 bumble bee species (e.g. Bombus pensylvanicus, B. affinis, B. terricola, etc.) that are declining or at risk of extinction 3-6-16. The global decline of bumble bee populations has been attributed to multiple interrelated factors, including habitat loss, pesticide exposure, pathogen spillover, and climate change 9. These stressors often interact synergistically, amplifying their cumulative effects and complicating conservation efforts 17. While these stressors have been relatively well documented, one potential contributor to bumble bee health decline remains notably underexplored and that is the role of mites associated with bumble bees. Mites (Acari) are one of the most evolutionary diverse groups of arthropods, exhibiting a wide range of life-history strategies. They play vital roles in both natural and managed ecosystems yet remain poorly studied due to their microscopic size and the difficulties involved in their detection and identification 11- 14-24. Consequently, the biology and ecological functions of many mite species remain unknown. To date, at least 91 mite species have been documented in association with bumble bees worldwide 13. These mites are reported to engage in a range of ecological interactions, from phoresy and commensalism to harmful parasitism 21. Many are obligate associates, relying on bumble bees for dispersal, reproduction, or access to food resources 7-10. In Ontario, Canada, a recent study recorded 33 mite species associated with 11 Bombus species, with nearly half being obligate associates 10. Although it has been proposed that these mites may provide neutral or even beneficial services, their potential to become parasitic, disrupt bee behavior (e.g. flight and movement), or deplete essential resources like pollen and nectar remains largely unexplored. The ultimate impact of phoretic mites on bee individuals as well as colony health and stability warrants further investigation. It has also been proposed that some of the mites associated with bumble bees can serve as vectors of pathogens , like Crithidia bombi, Nosema bombi, and Apicystis bombi detected within mites collected from Bombus spp., suggesting a possible role in disease transmission or persistence within bee colonies 19. Investigating the diversity, behavior, and nest-level interactions of these mites is essential for developing comprehensive and effective conservation strategies for bumblebees. These associations may significantly affect immunity, reproduction, and survival, and thus have wider implications for pollination services. Addressing this knowledge gap is vital to pollinator protection efforts. Current regulations surrounding the breeding, hygiene, and international movement of commercially used bumblebees are limited, and greater understanding of mite associations is essential to inform and support a more responsible and sustainable pollination industry. The general objective of our K2A group is to advance knowledge of bumblebee mite diversity, behavior and ecology by addressing key knowledge gaps in order to support bumblebee conservation and responsible use as commercial pollinators. This research aims not only to generate new scientific insights, but also to translate these findings into actionable strategies that support bee conservation and sustainable farming practices. By guiding the responsible production and use of managed bees, our work will help ensure that emerging knowledge contributes directly to the development of evidence-based interventions and best practices that promote pollinator health and agricultural sustainability. Research Objectives Objective 1 – Diversity and Distribution of Phoretic and Nest-Dwelling Mites Associated with Wild and Commercial Bumble Bees in Quebec This objective focuses on documenting and comparing the diversity, distribution, and community structure of phoretic and nest-dwelling mites associated with wild and commercially managed bumble bees (e.g. B. impatiens and B. griseocollis.) in Quebec. Bees will be collected from natural habitats and greenhouse populations to ensure ecological coverage. Phoretic mites will be removed under a stereomicroscope, preserved in ethanol, and identified using morphological keys and COI barcoding. Additional data will come from Bombus specimens preserved at the Insectarium de Montréal and Collection Ouellet-Robert, collected from various sites across Quebec. Nest-dwelling mites will be studied from wild nests (located via queen tracking or ground searches) and commercial hives using Bombus impatiens and B. griseocollis. Nests will be collected and dissected in the laboratory at two key stages of colony development: (1) during brood-rearing and peak worker activity in mid-summer, when mite reproductive cycles are most active and diverse communities are present 7, and (2) during the reproductive/dispersal phase in late summer or early fall, when phoretic deutonymphs begin attaching to new queens and males for overwintering and dispersal 10-20. Mites will be extracted using direct collection, Berlese–Tullgren funnels, and flotation methods. Comparative analyses will evaluate differences in mite diversity and community structure between wild and managed systems to understand how habitat and bee management influence mite assemblages. Objective 2 – Characterizing mite communities and their interactions within bumble bee nests This objective aims to characterize the diversity, composition, and ecological roles of mite communities associated with wild and commercially managed bumble bees. Sampling will focus on Bombus impatiens and B. griseocollis from both wild populations and commercial colonies. Mites will be collected from individual bees and nest materials and identified using a combination of morphological taxonomy and molecular barcoding to ensure accuracy and detect cryptic species. Environmental and management factors will be recorded to contextualize host–mite associations. Alpha diversity (e.g., species richness, Shannon index) and beta diversity metrics will be calculated; NMDS will visualize community differences, and PERMANOVA will test for statistical significance. To further investigate mite-host interactions and ecological function, selected nests will be dissected and placed in transparent observation chambers for behavioral monitoring under a stereomicroscope with video recording. Assays will focus on interactions between mites and (1) bee brood (eggs, larvae, pupae) to assess potential predation, parasitism, or phoresy; (2) stored resources (pollen, nectar) to examine feeding behavior; (3) other nest organisms (e.g., mites, fungi, nematodes); and (4) nest materials (wax, detritus) to understand habitat use. High-resolution video and time-lapse imaging will be used to quantify mite activity and infer their ecological roles, whether parasitic, mutualistic, commensal, or detritivorous—and their potential impacts on colony health and function. Objective 3– To investigate whether/how phoretic mites associated with bumble bees function as vectors for certain pathogens. To assess the potential role of phoretic mites as pathogen vectors in bumble bees, mites will be collected from wild and commercially managed Bombus spp. colonies across Quebec and Ontario. Using fine forceps under a stereomicroscope, mites will be removed and preserved in 95% ethanol, either individually or pooled by host or site. DNA will be extracted from ~50 samples using protocols optimized for small arthropods to retain both mite and microbial DNA. Samples will be screened for key bumble bee pathogens, including Nosema bombi, Crithidia bombi, Apicystis bombi, and viruses like DWV and BQCV via PCR or qPCR with species-specific primers 19. Positive detections will be validated by gel electrophoresis and, where needed, Sanger sequencing. Resulting sequences will be compared to reference databases to assess pathogen identity and relevance. This will clarify whether phoretic mites act as mechanical carriers or reservoirs of infectious agents in bee populations. 2. Nature of the partnership and expected deliverables (maximum 1 page) This project will be carried out in close collaboration with several institutional and academic partners, drawing on complementary expertise and shared infrastructure to achieve the research goals. The lead researcher, postdoctoral fellow Dr. Elham Arjomandi, will be based at Concordia University under the primary supervision of Dr. Emma Despland, who brings extensive expertise in insect behavior and ecology. Co-supervisors contribute targeted strengths essential to the project: Dr. Frédéric Beaulieu (Agriculture and Agri-Food Canada) provides specialized knowledge in acarology and mite taxonomy; Dr. Mathilde Tissier (UQÀM) has expertise in wild bumblebee ecology and established connections with farming communities to support fieldwork and stakeholder engagement; Dr. Colin Favret (Université de Montréal) contributes expertise in morphological and molecular identification of insects and mites; and Dr. Rassim Khelifa (Concordia University) offers additional strengths in agricultural ecology and molecular tools. This interdisciplinary supervisory team ensures robust support across all aspects of the project, from field sampling and species identification to behavioral analysis and ecological modeling. Field and laboratory work will involve partnership with Insectarium de Montréal, Concordia University, Koppert (industry producer of commercial bumble bees), Canada and IRDA (Institut de recherche et de développement en agroenvironnement). The Insectarium and Collection Ouellet-Robert will provide access to a rich repository of preserved bumble bee specimens from across Quebec, enabling expanded geographic coverage and off-season research continuity for bee mites collection and identification. This resource is particularly important during fall and winter when fresh field sampling becomes logistically challenging. WPC, an experienced conservation non-profit organization, will contribute expertise in bumble bee conservation and support access to captive-reared bumble bee colonies, wild populations for field sampling, as well as assistance in locating and collecting wild nests. In addition, commercial partners such as bee breeders, greenhouses, and berry producers in Quebec will facilitate access to managed bumble bee colonies for sampling and nest dissection. This collaboration is key to assessing the biodiversity of mites and potential spillover risks between managed and wild bumble bee populations, particularly concerning mite transmission and pathogen dynamics. This partnership will yield several key deliverables with both scientific and applied value. A comprehensive database of mite species associated with Bombus spp. including data from both museum collections and fresh field samples will be created, forming the basis for multiple peer-reviewed scientific manuscripts on mite biodiversity, behavior, and their potential role as vectors of pathogens. Illustrated identification keys for common mite taxa will be developed to support researchers, conservation practitioners, bee breeders and students. In addition, all identified mite species, their host associations, ecological roles, and reference images will be compiled into a publicly accessible website designed to aid in identification and raise awareness of mite diversity in bumble bee colonies. Findings will also be presented at national and international conferences. In collaboration with the Insectarium de Montréal, public outreach materials and activities will be co-developed to highlight mites as an overlooked threat to pollinator health. Practical recommendations will be delivered to Wildlife Preservation Canada and greenhouse and farm industry partners with whom Mathilde Tissier has connection (e.g., bee breeders (Koppert Canada), five greenhouse producers (organic and conventional) in Québec (located in Compton, Brome and Waterville) and three producers of blueberry and cranberry in Saguenay-Lac-Saint-Jean and Drummondville to support their management strategies aimed at reducing biotic stressors on bumble bee populations. Collectively, this research will provide an in-depth understanding of the diversity, ecology, and behavior of mites associated with bumble bees in Quebec, Canada. By investigating both phoretic and nest-dwelling mites, and comparing communities in wild versus managed colonies, the project will uncover previously unrecognized stressors that may affect colony health and pollination efficiency, especially in greenhouse systems. These biotic stressors may interact with other pressures such as pesticides and habitat loss, compounding their effects on bumble bee resilience. This is particularly critical in controlled agricultural environments, where the introduction and spillover of mites from commercial colonies into wild populations could have unforeseen ecological consequences. Ultimately, the outcomes of this work will enhance our understanding of host-symbiont dynamics and inform more effective conservation strategies at a time of global pollinator decline. 3. Calendar of the proposed scientific collaboration, with the expected milestones for the deliverables (max 1 page) The proposed research will span two years (September 2025–August 2027) and is structured to maximize field seasons, leverage existing specimen collections, and ensure continuous lab-based progress during off-season periods. Fieldwork and nest sampling will be concentrated in spring and summer, while laboratory work, including mite processing, taxonomic identification, DNA extraction, and pathogen screening will proceed year-round. The use of preserved specimens from the Insectarium de Montréal ensures consistent research activity, particularly during the fall and winter months when live sampling is limited. Data analysis, manuscript writing, and knowledge mobilization (including development of an online ID resource and outreach activities) are scheduled for the second year. This calendar reflects coordinated contributions from academic, and conservation partners and ensures timely delivery of all proposed scientific and outreach deliverables. 4. Consideration of equity, diversity, and inclusiveness This project is being led by a team with a strong commitment to equity, diversity, and inclusion, demonstrated through effective knowledge exchange and collaboration with diverse stakeholders. Team members have established relationships with key communities; for example, building trusted connections with farmers to ensure their perspectives are meaningfully integrated and adequately represented throughout the project. The research will be conducted in partnership with multiple institutions and organizations across Quebec, creating opportunities for broad engagement with students, conservation practitioners, and other stakeholders. The project also includes the development of open-access resources (e.g., an online mite ID database), supporting inclusive science communication and training for both academic and non-academic audiences. 5. Data accessibility All data generated through this project, including mite species records, host associations, molecular sequences, and pathogen screening results will be made publicly available to ensure transparency, reproducibility, and accessibility. Molecular sequence data (e.g., COI barcodes, pathogen sequences) will be submitted to GenBank and BOLD systems. Occurrence and host-association records will be shared through open-access biodiversity platforms such as GBIF. In addition, a dedicated web portal will be developed to host illustrated identification keys and ecological profiles of mite species associated with bumble bees in Quebec. This online resource will be accessible to researchers, conservation practitioners, bee breeders, greenhouse growers and the public, and will support both scientific and applied pollinator health initiatives. Metadata and protocols will follow standard biodiversity informatics practices to ensure interoperability and long-term preservation. References 1 Anderson, M. J. (2001). A new method for non‐parametric multivariate analysis of variance. Austral ecology, 26(1), 32-46. 2 Bartomeus, I., Ascher, J. S., Gibbs, J., Danforth, B. N., Wagner, D. L., Hedtke, S. M., & Winfree, R. (2013). Historical changes in northeastern US bee pollinators related to shared ecological traits. Proceedings of the National Academy of Sciences, 110(12), 4656-4660. 3 Cameron, S. A., Lozier, J. D., Strange, J. P., Koch, J. B., Cordes, N., Solter, L. F., & Griswold, T. L. (2011). Patterns of widespread decline in North American bumble bees. Proceedings of the National Academy of Sciences, 108(2), 662-667. 4 Clarke, K. R. (1993). Non‐parametric multivariate analyses of changes in community structure. Australian journal of ecology, 18(1), 117-143. 5 Colla, S. R., Otterstatter, M. C., Gegear, R. J., & Thomson, J. D. (2006). Plight of the bumble bee: pathogen spillover from commercial to wild populations. Biological conservation, 129(4), 461-467. 6 COSEWIC (2015). COSEWIC assessment and status report on the Yellow-banded Bumble Bee Bombus terricola in Canada, Committee on the Status of Endangered Wildlife in Canada. 7 Eickwort, G. C. (1994). Evolution and life-history patterns of mites associated with bees. In Mites: ecological and evolutionary analyses of life-history patterns (pp. 218-251). 8 Goulson, D., Lepais, O., O’Connor, S., Osborne, J. L., Sanderson, R. A., Cussans, J., & Darvill, B. (2010). Effects of land use at a landscape scale on bumblebee nest density and survival. Journal of Applied Ecology, 47(6), 1207-1215. 9 Goulson, D., Nicholls, E., Botías, C., & Rotheray, E. L. (2015). Bee declines driven by combined stress from parasites, pesticides, and lack of flowers. Science, 347(6229), 1255957. 10 Hass, A. L., Brachmann, L., Batáry, P., Clough, Y., Behling, H., & Tscharntke, T. (2019). Maize‐dominated landscapes reduce bumblebee colony growth through pollen diversity loss. Journal of Applied Ecology, 56(2), 294-304. 11 Hoy, M. A. (2011). Agricultural acarology: introduction to integrated mite management (7). CRC press. 12 James, R. R., & Pitts-Singer, T. L. (Eds.). (2008). Bee pollination in agricultural ecosystems. Oxford University Press. 13 Klimov, P. B., O’Connor, B. M., Ochoa, R., Bauchan, G. R., & Scher, J. (2017). Bee Mite ID-an online resource on identification of mites associated with bees of the World. Journal of the Acarological Society of Japan, 26(1), 25-29. 14 Krantz, G. W., & Walter, D. E. (Eds.). (2009). A manual of acarology (3rd ed.). Lubbock: Texas Tech University Press. 807 p. 338 b/w illustrations; 60 figures ISBN 978-0-89672-620-8. 15 Krantz, G. W. Gerald William 1928- editor, and David Evans 1950- editor Walter. A Manual of Acarology. Lubbock, Texas Texas Tech University Press, 200.Cameron, S. A., & Sadd, B. M. (2020). Global trends in bumble bee health. Annual review of entomology, 65(1), 209-232. 16 MacPhail, V. J., Richardson, L. L., & Colla, S. R. (2019). Incorporating citizen science, museum specimens, and field work into the assessment of extinction risk of the American Bumble bee (Bombus pensylvanicus De Geer 1773) in Canada. Journal of Insect Conservation, 23, 597-611. 17 Meeus, I., Pisman, M., Smagghe, G., & Piot, N. (2018). Interaction effects of different drivers of wild bee decline and their influence on host–pathogen dynamics. Current Opinion in Insect Science, 26, 136-141. 18 Otterstatter, M. C., & Thomson, J. D. (2008). Does pathogen spillover from commercially reared bumble bees threaten wild pollinators? PloS one, 3(7), e2771. 19 Revainera, P. D., Quintana, S., Fernández de Landa, G., Meroi Arcerito, F., Lucía, M., Abrahamovich, A. H., ... & Maggi, M. D. (2020). Phoretic mites on South American bumblebees (Bombus spp.) as parasite carriers: a historical input. Apidologie, 51, 455-464. 20 Rożej, E., Witaliński, W., Szentgyörgyi, H., Wantuch, M., Moroń, D., & Woyciechowski, M. (2012). Mite species inhabiting commercial bumblebee (Bombus terrestris) nests in Polish greenhouses. Experimental and Applied Acarology, 56, 271-282. 21 Seeman, O. D., & Walter, D. E. (2023). Phoresy and mites: More than just a free ride. Annual Review of Entomology, 68(1), 69-88. 22 Tuell, J. K., & Isaacs, R. (2010). Weather during bloom affects pollination and yield of highbush blueberries. Journal of economic entomology, 103(3), 557-562. 23 Velthuis, H. H., & Van Doorn, A. (2006). A century of advances in bumblebee domestication and the economic and environmental aspects of its commercialization for pollination. Apidologie, 37(4), 421-451. 24 Walter, D. E., Proctor, H. C., Walter, D. E., & Proctor, H. C. (2013). Mites and biological diversity. Mites: Ecology, Evolution & Behaviour: Life at a Microscale, 447-459. Pour approfondir l'étude des interactions acariens-hôtes et de la fonction écologique, des nids sélectionnés seront disséqués et placés dans des chambres d'observation transparentes pour un suivi comportemental sous un stéréomicroscope avec enregistrement vidéo. Les essais se concentreront sur les interactions entre les acariens et (1) le couvain d'abeilles (œufs, larves, nymphes) pour évaluer le potentiel de prédation, de parasitisme ou de phorésie ; (2) les ressources stockées (pollen, nectar) pour examiner le comportement alimentaire ; (3) d'autres organismes du nid (par exemple, acariens, champignons, nématodes) ; et (4) les matériaux du nid (cire, détritus) pour comprendre l'utilisation de l'habitat. La vidéo haute résolution et l'imagerie time-lapse seront utilisées pour quantifier l'activité des acariens et déduire leurs rôles écologiques, qu'ils soient parasites, mutualistes, commensaux ou détritivores, ainsi que leurs impacts potentiels sur la santé et le fonctionnement des colonies. Objectif 3- Étudier si/comment les acariens phorétiques associés aux bourdons fonctionnent comme vecteurs de certains pathogènes. Pour évaluer le rôle potentiel des acariens phorétiques comme vecteurs de pathogènes chez les bourdons, des acariens seront prélevés dans des colonies de Bombus spp. sauvages et gérées commercialement au Québec et en Ontario. À l'aide de pinces fines et sous un stéréomicroscope, les acariens seront prélevés et conservés dans de l'éthanol à 95 %, soit individuellement, soit regroupés par hôte ou par site. L'ADN sera extrait d'environ 50 échantillons à l'aide de protocoles optimisés pour les petits arthropodes afin de conserver à la fois l'ADN des acariens et l'ADN microbien. Les échantillons seront examinés pour détecter les principaux agents pathogènes des bourdons, y compris Nosema bombi, Crithidia bombi, Apicystis bombi, et les virus comme DWV et BQCV par PCR ou qPCR avec des amorces spécifiques à l'espèce 19. Les détections positives seront validées par électrophorèse sur gel et, le cas échéant, par séquençage Sanger. Les séquences obtenues seront comparées aux bases de données de référence afin d'évaluer l'identité et la pertinence du pathogène. Cela permettra de déterminer si les acariens phorétiques agissent comme des porteurs mécaniques ou des réservoirs d'agents infectieux dans les populations d'abeilles. 2. Nature du partenariat et résultats attendus (maximum 1 page) Ce projet sera réalisé en étroite collaboration avec plusieurs partenaires institutionnels et universitaires, en s'appuyant sur des expertises complémentaires et des infrastructures partagées pour atteindre les objectifs de la recherche. La chercheuse principale, la boursière postdoctorale Elham Arjomandi, sera basée à l'Université Concordia sous la supervision principale de la Dre Emma Despland, qui apporte une grande expertise dans le comportement et l'écologie des insectes. Les co-superviseurs apportent des forces ciblées essentielles au projet : Frédéric Beaulieu (Agriculture et Agroalimentaire Canada) apporte des connaissances spécialisées en acarologie et en taxonomie des acariens ; Mathilde Tissier (UQÀM) possède une expertise en écologie des bourdons sauvages et a établi des liens avec les communautés agricoles pour soutenir le travail sur le terrain et l'engagement des parties prenantes ; Colin Favret (Université de Montréal) apporte une expertise en identification morphologique et moléculaire des insectes et des acariens ; et Rassim Khelifa (Université Concordia) apporte des forces additionnelles en écologie agricole et en outils moléculaires. Cette équipe de supervision interdisciplinaire assure un soutien solide à tous les aspects du projet, depuis l'échantillonnage sur le terrain et l'identification des espèces jusqu'à l'analyse comportementale et la modélisation écologique. Les travaux sur le terrain et en laboratoire impliqueront un partenariat avec l'Insectarium de Montréal, l'Université Concordia, Koppert (producteur industriel de bourdons commerciaux), le Canada et l'IRDA (Institut de recherche et de développement en agroenvironnement). L'Insectarium et la Collection Ouellet-Robert donneront accès à un riche dépôt de spécimens de bourdons conservés provenant de tout le Québec, ce qui permettra d'élargir la couverture géographique et d'assurer la continuité des recherches hors saison pour la collecte et l'identification des acariens de l'abeille. Cette ressource est particulièrement importante en automne et en hiver, lorsque l'échantillonnage sur le terrain devient difficile sur le plan logistique. Le CMP, une organisation à but non lucratif expérimentée dans le domaine de la conservation, apportera son expertise en matière de conservation des bourdons et facilitera l'accès aux colonies de bourdons élevés en captivité, aux populations sauvages pour l'échantillonnage sur le terrain, ainsi qu'à l'assistance pour la localisation et la collecte de nids sauvages. En outre, des partenaires commerciaux tels que des éleveurs d'abeilles, des serres et des producteurs de baies du Québec faciliteront l'accès aux colonies de bourdons gérées pour l'échantillonnage et la dissection des nids. Cette collaboration est essentielle pour évaluer la biodiversité des acariens et les risques potentiels de propagation entre les populations de bourdons gérés et sauvages, en particulier en ce qui concerne la transmission des acariens et la dynamique des agents pathogènes. Ce partenariat débouchera sur plusieurs résultats clés ayant une valeur à la fois scientifique et appliquée. Une base de données complète des espèces d'acariens associées à Bombus spp. comprenant des données provenant à la fois de collections de musées et d'échantillons frais prélevés sur le terrain sera créée, constituant la base de plusieurs manuscrits scientifiques évalués par des pairs sur la biodiversité des acariens, leur comportement et leur rôle potentiel en tant que vecteurs d'agents pathogènes. Des clés d'identification illustrées pour les taxons d'acariens communs seront élaborées pour aider les chercheurs, les praticiens de la conservation, les éleveurs d'abeilles et les étudiants. En outre, toutes les espèces d'acariens identifiées, leurs associations d'hôtes, leurs rôles écologiques et les images de référence seront compilés sur un site web accessible au public, conçu pour faciliter l'identification et sensibiliser à la diversité des acariens dans les colonies de bourdons. Les résultats seront également présentés lors de conférences nationales et internationales. En collaboration avec l'Insectarium de Montréal, du matériel et des activités de sensibilisation du public seront élaborés afin de mettre en évidence le fait que les acariens constituent une menace négligée pour la santé des pollinisateurs. Des recommandations pratiques seront transmises à Préservation de la faune Canada et aux partenaires de l'industrie serricole et agricole avec lesquels Mathilde Tissier a des liens (p. ex. des éleveurs d'abeilles (Koppert Canada), cinq producteurs serricoles (biologiques et conventionnels) du Québec (situés à Compton, Brome et Waterville) et trois producteurs de bleuets et de canneberges du Saguenay-Lac-Saint-Jean et de Drummondville) afin d'appuyer leurs stratégies de gestion visant à réduire les facteurs de stress biotiques sur les populations de bourdons. Collectivement, cette recherche fournira une compréhension approfondie de la diversité, de l'écologie et du comportement des acariens associés aux bourdons au Québec, Canada. En étudiant les acariens phorétiques et les acariens vivant dans les nids, et en comparant les communautés dans les colonies sauvages et les colonies gérées, le projet permettra de découvrir des facteurs de stress précédemment méconnus qui peuvent affecter la santé des colonies et l'efficacité de la pollinisation, en particulier dans les systèmes de serres. Ces facteurs de stress biotiques peuvent interagir avec d'autres pressions telles que les pesticides et la perte d'habitat, aggravant ainsi leurs effets sur la résilience des bourdons. Cela est particulièrement important dans les environnements agricoles contrôlés, où l'introduction et la propagation des acariens des colonies commerciales dans les populations sauvages pourraient avoir des conséquences écologiques imprévues. En fin de compte, les résultats de ce travail amélioreront notre compréhension de la dynamique hôte-symbionte et permettront d'élaborer des stratégies de conservation plus efficaces en cette période de déclin des pollinisateurs à l'échelle mondiale. 3. Calendar of the proposed scientific collaboration, with the expected milestones for the deliverables (max 1 page) The proposed research will span two years (September 2025–August 2027) and is structured to maximize field seasons, leverage existing specimen collections, and ensure continuous lab-based progress during off-season periods. Fieldwork and nest sampling will be concentrated in spring and summer, while laboratory work, including mite processing, taxonomic identification, DNA extraction, and pathogen screening will proceed year-round. The use of preserved specimens from the Insectarium de Montréal ensures consistent research activity, particularly during the fall and winter months when live sampling is limited. Data analysis, manuscript writing, and knowledge mobilization (including development of an online ID resource and outreach activities) are scheduled for the second year. This calendar reflects coordinated contributions from academic, and conservation partners and ensures timely delivery of all proposed scientific and outreach deliverables. 4. Prise en compte de l'équité, de la diversité et de l'inclusion Ce projet est mené par une équipe qui s'est fermement engagée en faveur de l'équité, de la diversité et de l'inclusion, comme en témoignent l'échange efficace de connaissances et la collaboration avec diverses parties prenantes. Les membres de l'équipe ont établi des relations avec des communautés clés ; par exemple, en établissant des liens de confiance avec les agriculteurs pour s'assurer que leurs points de vue sont intégrés de manière significative et représentés de manière adéquate tout au long du projet. La recherche sera menée en partenariat avec de nombreuses institutions et organisations à travers le Québec, créant ainsi des opportunités d'engagement avec les étudiants, les praticiens de la conservation et d'autres parties prenantes. Le projet comprend également le développement de ressources en libre accès (par exemple, une base de données d'identification des acariens en ligne), soutenant la communication scientifique inclusive et la formation pour les publics académiques et non académiques. 5. Data accessibility All data generated through this project, including mite species records, host associations, molecular sequences, and pathogen screening results will be made publicly available to ensure transparency, reproducibility, and accessibility. Molecular sequence data (e.g., COI barcodes, pathogen sequences) will be submitted to GenBank and BOLD systems. Occurrence and host-association records will be shared through open-access biodiversity platforms such as GBIF. In addition, a dedicated web portal will be developed to host illustrated identification keys and ecological profiles of mite species associated with bumble bees in Quebec. This online resource will be accessible to researchers, conservation practitioners, bee breeders, greenhouse growers and the public, and will support both scientific and applied pollinator health initiatives. Metadata and protocols will follow standard biodiversity informatics practices to ensure interoperability and long-term preservation.