1
|
Schödl I, Odemer R, Becher MA, Berg S, Otten C, Grimm V, Groeneveld J. Simulation of Varroa mite control in honey bee colonies without synthetic acaricides: Demonstration of Good Beekeeping Practice for Germany in the BEEHAVE model. Ecol Evol 2022; 12:e9456. [PMID: 36381398 PMCID: PMC9643073 DOI: 10.1002/ece3.9456] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/09/2022] [Accepted: 10/10/2022] [Indexed: 11/11/2022] Open
Abstract
The BEEHAVE model simulates the population dynamics and foraging activity of a single honey bee colony (Apis mellifera) in great detail. Although it still makes numerous simplifying assumptions, it appears to capture a wide range of empirical observations. It could, therefore, in principle, also be used as a tool in beekeeper education, as it allows the implementation and comparison of different management options. Here, we focus on treatments aimed at controlling the mite Varroa destructor. However, since BEEHAVE was developed in the UK, mite treatment includes the use of a synthetic acaricide, which is not part of Good Beekeeping Practice in Germany. A practice that consists of drone brood removal from April to June, treatment with formic acid in August/September, and treatment with oxalic acid in November/December. We implemented these measures, focusing on the timing, frequency, and spacing between drone brood removals. The effect of drone brood removal and acid treatment, individually or in combination, on a mite-infested colony was examined. We quantify the efficacy of Varroa mite control as the reduction of mites in treated bee colonies compared to untreated bee colonies. We found that drone brood removal was very effective, reducing mites by 90% at the end of the first simulation year after the introduction of mites. This value was significantly higher than the 50-67% reduction expected by bee experts and confirmed by empirical studies. However, literature reports varying percent reductions in mite numbers from 10 to 85% after drone brood removal. The discrepancy between model results, empirical data, and expert estimates indicate that these three sources should be reviewed and refined, as all are based on simplifying assumptions. These results and the adaptation of BEEHAVE to the Good Beekeeping Practice are a decisive step forward for the future use of BEEHAVE in beekeeper education in Germany and anywhere where organic acids and drone brood removal are utilized.
Collapse
Affiliation(s)
- Isabel Schödl
- Department of Ecological ModellingHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Richard Odemer
- Julius Kühn‐Institute (JKI), Federal Research Centre for Cultivated PlantsInstitute for Bee ProtectionBraunschweigGermany
| | - Matthias A. Becher
- Artificial Life Laboratory, Institute of Biology, Karl‐Franzens University GrazGrazAustria
| | - Stefan Berg
- Bavarian State Institute for Viticulture and Horticulture, Institute for Bee Research and BeekeepingVeitshöchheimGermany
| | - Christoph Otten
- Service Centre for Rural Areas (DLR), Expert Centre for Bees and BeekeepingMayenGermany
| | - Volker Grimm
- Department of Ecological ModellingHelmholtz Centre for Environmental Research – UFZLeipzigGermany
- Plant Ecology and Nature ConservationUniversity of PotsdamPotsdamGermany
| | - Jürgen Groeneveld
- Department of Ecological ModellingHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| |
Collapse
|
2
|
Twiston‐Davies G, Becher MA, Osborne JL. BEE‐STEWARD: A research and decision‐support software for effective land management to promote bumblebee populations. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Matthias A. Becher
- Environment and Sustainability Institute University of Exeter Penryn UK
- Artificial Life Laboratory Institute of Biology Karl‐Franzens University Graz Graz Austria
| | - Juliet L. Osborne
- Environment and Sustainability Institute University of Exeter Penryn UK
| |
Collapse
|
3
|
Bulson L, Becher MA, McKinley TJ, Wilfert L. Long-term effects of antibiotic treatments on honeybee colony fitness: A modelling approach. J Appl Ecol 2021; 58:70-79. [PMID: 33542585 PMCID: PMC7839786 DOI: 10.1111/1365-2664.13786] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/11/2020] [Indexed: 11/30/2022]
Abstract
Gut microbiome disequilibrium is increasingly implicated in host fitness reductions, including for the economically important and disease-challenged western honey bee Apis mellifera. In laboratory experiments, the antibiotic tetracycline, which is used to prevent American Foulbrood Disease in countries including the US, elevates honey bee mortality by disturbing the microbiome. It is unclear, however, how elevated individual mortality affects colony-level fitness.We used an agent-based model (BEEHAVE) and empirical data to assess colony-level effects of antibiotic-induced worker bee mortality, by measuring colony size. We investigated the relationship between the duration that the antibiotic-induced mortality probability is imposed for and colony size.We found that when simulating antibiotic-induced mortality of worker bees from just 60 days per year, up to a permanent effect, the colony is reduced such that tetracycline treatment would not meet the European Food Safety Authority's (EFSA) honey bee protection goals. When antibiotic mortality was imposed for the hypothetical minimal exposure time, which assumes that antibiotics only impact the bee's fitness during the recommended treatment period of 15 days in both spring and autumn, the colony fitness reduction was only marginally under the EFSA's threshold. Synthesis and Applications. Modelling colony-level impacts of antibiotic treatment shows that individual honey bee worker mortality can lead to colony mortality. To assess the full impact, the persistence of antibiotic-induced mortality in honey bees must be determined experimentally, in vivo. We caution that as the domestication of new insect species increases, maintaining healthy gut microbiomes is of paramount importance to insect health and commercial productivity. The recommendation from this work is to limit prophylactic use of antibiotics and to not exceed recommended treatment strategies for domesticated insects. This is especially important for highly social insects as excess antibiotic use will likely decrease colony growth and an increase in colony mortality.
Collapse
Affiliation(s)
- Laura Bulson
- College of Life and Environment SciencesTremough CampusUniversity of ExeterPenrynUK
| | - Matthias A. Becher
- College of Life and Environment SciencesTremough CampusUniversity of ExeterPenrynUK
| | | | - Lena Wilfert
- College of Life and Environment SciencesTremough CampusUniversity of ExeterPenrynUK
- Institute of Evolutionary Ecology and Conservation GenomicsUniversity of UlmUlmGermany
| |
Collapse
|
4
|
Horn J, Becher MA, Johst K, Kennedy PJ, Osborne JL, Radchuk V, Grimm V. Honey bee colony performance affected by crop diversity and farmland structure: a modeling framework. Ecol Appl 2021; 31:e02216. [PMID: 32810342 DOI: 10.1002/eap.2216] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/20/2020] [Accepted: 03/17/2020] [Indexed: 06/11/2023]
Abstract
Forage availability has been suggested as one driver of the observed decline in honey bees. However, little is known about the effects of its spatiotemporal variation on colony success. We present a modeling framework for assessing honey bee colony viability in cropping systems. Based on two real farmland structures, we developed a landscape generator to design cropping systems varying in crop species identity, diversity, and relative abundance. The landscape scenarios generated were evaluated using the existing honey bee colony model BEEHAVE, which links foraging to in-hive dynamics. We thereby explored how different cropping systems determine spatiotemporal forage availability and, in turn, honey bee colony viability (e.g., time to extinction, TTE) and resilience (indicated by, e.g., brood mortality). To assess overall colony viability, we developed metrics, PH and PP, which quantified how much nectar and pollen provided by a cropping system per year was converted into a colony's adult worker population. Both crop species identity and diversity determined the temporal continuity in nectar and pollen supply and thus colony viability. Overall farmland structure and relative crop abundance were less important, but details mattered. For monocultures and for four-crop species systems composed of cereals, oilseed rape, maize, and sunflower, PH and PP were below the viability threshold. Such cropping systems showed frequent, badly timed, and prolonged forage gaps leading to detrimental cascading effects on life stages and in-hive work force, which critically reduced colony resilience. Four-crop systems composed of rye-grass-dandelion pasture, trefoil-grass pasture, sunflower, and phacelia ensured continuous nectar and pollen supply resulting in TTE > 5 yr, and PH (269.5 kg) and PP (108 kg) being above viability thresholds for 5 yr. Overall, trefoil-grass pasture, oilseed rape, buckwheat, and phacelia improved the temporal continuity in forage supply and colony's viability. Our results are hypothetical as they are obtained from simplified landscape settings, but they nevertheless match empirical observations, in particular the viability threshold. Our framework can be used to assess the effects of cropping systems on honey bee viability and to develop land-use strategies that help maintain pollination services by avoiding prolonged and badly timed forage gaps.
Collapse
Affiliation(s)
- Juliane Horn
- Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig, 04318, Germany
| | - Matthias A Becher
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn Cornwall, TR10 9FE, UK
| | - Karin Johst
- Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig, 04318, Germany
| | - Peter J Kennedy
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn Cornwall, TR10 9FE, UK
| | - Juliet L Osborne
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn Cornwall, TR10 9FE, UK
| | - Viktoriia Radchuk
- Leibniz Institute for Zoo and Wildlife Research (IZW) in the Forschungsverbund Berlin e.V., Alfred-Kowalke-Straße 17, Berlin, 10315, Germany
| | - Volker Grimm
- Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, Leipzig, 04318, Germany
- Plant Ecology and Nature Conservation, University of Potsdam, Am Mühlenberg 3, Potsdam, 14476, Germany
| |
Collapse
|
5
|
Knapp JL, Becher MA, Rankin CC, Twiston‐Davies G, Osborne JL. Bombus terrestris in a mass-flowering pollinator-dependent crop: A mutualistic relationship? Ecol Evol 2019; 9:609-618. [PMID: 30680141 PMCID: PMC6342091 DOI: 10.1002/ece3.4784] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 11/05/2018] [Indexed: 11/08/2022] Open
Abstract
Bumblebees (Bombus spp.) rely on an abundant and diverse selection of floral resources to meet their nutritional requirements. In farmed landscapes, mass-flowering crops can provide an important forage resource for bumblebees, with increased visitation from bumblebees into mass-flowering crops having an additional benefit to growers who require pollination services. This study explores the mutualistic relationship between Bombus terrestris L. (buff-tailed bumblebee), a common species in European farmland, and the mass-flowering crop courgette (Cucurbita pepo L.) to see how effective B. terrestris is at pollinating courgette and in return how courgette may affect B. terrestris colony dynamics. By combining empirical data on nectar and pollen availability with model simulations using the novel bumblebee model Bumble-BEEHAVE, we were able to quantify and simulate for the first time, the importance of courgette as a mass-flowering forage resource for bumblebees. Courgette provides vast quantities of nectar to ensure a high visitation rate, which combined with abundant pollen grains, enables B. terrestris to have a high pollination potential. While B. terrestris showed a strong fidelity to courgette flowers for nectar, courgette pollen was not found in any pollen loads from returning foragers. Nonetheless, model simulations showed that early season courgette (nectar) increased the number of hibernating queens, colonies, and adult workers in the modeled landscapes. Synthesis and applications. Courgette has the potential to improve bumblebee population dynamics; however, the lack of evidence of the bees collecting courgette pollen in this study suggests that bees can only benefit from this transient nectar source if alternative floral resources, particularly pollen, are also available to fulfill bees' nutritional requirements in space and time. Therefore, providing additional forage resources could simultaneously improve pollination services and bumblebee populations.
Collapse
|
6
|
Becher MA, Twiston-Davies G, Penny TD, Goulson D, Rotheray EL, Osborne JL. Bumble-BEEHAVE: A systems model for exploring multifactorial causes of bumblebee decline at individual, colony, population and community level. J Appl Ecol 2018; 55:2790-2801. [PMID: 30449898 PMCID: PMC6221040 DOI: 10.1111/1365-2664.13165] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/23/2018] [Indexed: 12/03/2022]
Abstract
World‐wide declines in pollinators, including bumblebees, are attributed to a multitude of stressors such as habitat loss, resource availability, emerging viruses and parasites, exposure to pesticides, and climate change, operating at various spatial and temporal scales. Disentangling individual and interacting effects of these stressors, and understanding their impact at the individual, colony and population level are a challenge for systems ecology. Empirical testing of all combinations and contexts is not feasible. A mechanistic multilevel systems model (individual‐colony‐population‐community) is required to explore resilience mechanisms of populations and communities under stress. We present a model which can simulate the growth, behaviour and survival of six UK bumblebee species living in any mapped landscape. Bumble‐BEEHAVE simulates, in an agent‐based approach, the colony development of bumblebees in a realistic landscape to study how multiple stressors affect bee numbers and population dynamics. We provide extensive documentation, including sensitivity analysis and validation, based on data from literature. The model is freely available, has flexible settings and includes a user manual to ensure it can be used by researchers, farmers, policy‐makers, NGOs or other interested parties. Model outcomes compare well with empirical data for individual foraging behaviour, colony growth and reproduction, and estimated nest densities. Simulating the impact of reproductive depression caused by pesticide exposure shows that the complex feedback mechanisms captured in this model predict higher colony resilience to stress than suggested by a previous, simpler model. Synthesis and applications. The Bumble‐BEEHAVE model represents a significant step towards predicting bumblebee population dynamics in a spatially explicit way. It enables researchers to understand the individual and interacting effects of the multiple stressors affecting bumblebee survival and the feedback mechanisms that may buffer a colony against environmental stress, or indeed lead to spiralling colony collapse. The model can be used to aid the design of field experiments, for risk assessments, to inform conservation and farming decisions and for assigning bespoke management recommendations at a landscape scale.
The Bumble‐BEEHAVE model represents a significant step towards predicting bumblebee population dynamics in a spatially explicit way. It enables researchers to understand the individual and interacting effects of the multiple stressors affecting bumblebee survival and the feedback mechanisms that may buffer a colony against environmental stress, or indeed lead to spiralling colony collapse. The model can be used to aid the design of field experiments, for risk assessments, to inform conservation and farming decisions and for assigning bespoke management recommendations at a landscape scale.
Collapse
Affiliation(s)
- Matthias A Becher
- Environment and Sustainability Institute University of Exeter, Penryn Campus Cornwall UK
| | - Grace Twiston-Davies
- Environment and Sustainability Institute University of Exeter, Penryn Campus Cornwall UK
| | - Tim D Penny
- Environment and Sustainability Institute University of Exeter, Penryn Campus Cornwall UK.,School of Biological and Chemical Sciences Queen Mary University of London London UK
| | - Dave Goulson
- School of Life Sciences University of Sussex Sussex UK
| | | | - Juliet L Osborne
- Environment and Sustainability Institute University of Exeter, Penryn Campus Cornwall UK
| |
Collapse
|
7
|
Rumkee JCO, Becher MA, Thorbek P, Osborne JL. Modeling Effects of Honeybee Behaviors on the Distribution of Pesticide in Nectar within a Hive and Resultant in-Hive Exposure. Environ Sci Technol 2017; 51:6908-6917. [PMID: 28485584 DOI: 10.1021/acs.est.6b04206] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recently, the causes of honeybee colony losses have been intensely studied, showing that there are multiple stressors implicated in colony declines, one stressor being the exposure to pesticides. Measuring exposure of individual bees within a hive to pesticide is at least as difficult as assessing the potential exposure of foraging bees to pesticide. We present a model to explore how heterogeneity of pesticide distribution on a comb in the hive can be driven by worker behaviors. The model contains simplified behaviors to capture the extremes of possible heterogeneity of pesticide location/deposition within the hive to compare with exposure levels estimated by averaging values across the comb. When adults feed on nectar containing the average concentration of all pesticide brought into the hive on that particular day, it is likely representative of the worst-case exposure scenario. However, for larvae, clustering of pesticide in the comb can lead to higher exposure levels than taking an average concentration in some circumstances. The potential for extrapolating the model to risk assessment is discussed.
Collapse
Affiliation(s)
- Jack C O Rumkee
- Environment and Sustainability Institute, University of Exeter , Penryn Campus, Penryn, Cornwall TR10 9FE, U.K
| | - Matthias A Becher
- Environment and Sustainability Institute, University of Exeter , Penryn Campus, Penryn, Cornwall TR10 9FE, U.K
| | - Pernille Thorbek
- Environmental Safety, Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, U.K
| | - Juliet L Osborne
- Environment and Sustainability Institute, University of Exeter , Penryn Campus, Penryn, Cornwall TR10 9FE, U.K
| |
Collapse
|
8
|
Becher MA, Grimm V, Knapp J, Horn J, Twiston-Davies G, Osborne JL. BEESCOUT: A model of bee scouting behaviour and a software tool for characterizing nectar/pollen landscapes for BEEHAVE. Ecol Modell 2016; 340:126-133. [PMID: 27890965 PMCID: PMC5070411 DOI: 10.1016/j.ecolmodel.2016.09.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BEESCOUT is a spatially explicit, individual-based model of scouting bees. It determines the detection probabilities of food sources. It can be linked to the honey bee model BEEHAVE to predict colony development.
Social bees are central place foragers collecting floral resources from the surrounding landscape, but little is known about the probability of a scouting bee finding a particular flower patch. We therefore developed a software tool, BEESCOUT, to theoretically examine how bees might explore a landscape and distribute their scouting activities over time and space. An image file can be imported, which is interpreted by the model as a “forage map” with certain colours representing certain crops or habitat types as specified by the user. BEESCOUT calculates the size and location of these potential food sources in that landscape relative to a bee colony. An individual-based model then determines the detection probabilities of the food patches by bees, based on parameter values gathered from the flight patterns of radar-tracked honeybees and bumblebees. Various “search modes” describe hypothetical search strategies for the long-range exploration of scouting bees. The resulting detection probabilities of forage patches can be used as input for the recently developed honeybee model BEEHAVE, to explore realistic scenarios of colony growth and death in response to different stressors. In example simulations, we find that detection probabilities for food sources close to the colony fit empirical data reasonably well. However, for food sources further away no empirical data are available to validate model output. The simulated detection probabilities depend largely on the bees’ search mode, and whether they exchange information about food source locations. Nevertheless, we show that landscape structure and connectivity of food sources can have a strong impact on the results. We believe that BEESCOUT is a valuable tool to better understand how landscape configurations and searching behaviour of bees affect detection probabilities of food sources. It can also guide the collection of relevant data and the design of experiments to close knowledge gaps, and provides a useful extension to the BEEHAVE honeybee model, enabling future users to explore how landscape structure and food availability affect the foraging decisions and patch visitation rates of the bees and, in consequence, to predict colony development and survival.
Collapse
Affiliation(s)
- M A Becher
- Environment & Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, UK
| | - V Grimm
- UFZ, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318 Leipzig, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - J Knapp
- Environment & Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, UK
| | - J Horn
- UFZ, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318 Leipzig, Germany
| | - G Twiston-Davies
- Environment & Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, UK
| | - J L Osborne
- Environment & Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, UK
| |
Collapse
|
9
|
Horn J, Becher MA, Kennedy PJ, Osborne JL, Grimm V. Multiple stressors: using the honeybee model BEEHAVE to explore how spatial and temporal forage stress affects colony resilience. OIKOS 2015. [DOI: 10.1111/oik.02636] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Juliane Horn
- UFZ, Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15 DE-04318 Leipzig Germany
| | - Matthias A. Becher
- Environment and Sustainability Institute, Univ. of Exeter, Cornwall Campus; Penryn Cornwall TR10 9FE UK
| | - Peter J. Kennedy
- Environment and Sustainability Institute, Univ. of Exeter, Cornwall Campus; Penryn Cornwall TR10 9FE UK
| | - Juliet L. Osborne
- Environment and Sustainability Institute, Univ. of Exeter, Cornwall Campus; Penryn Cornwall TR10 9FE UK
| | - Volker Grimm
- UFZ, Helmholtz Centre for Environmental Research - UFZ; Permoserstr. 15 DE-04318 Leipzig Germany
- Inst. for Biochemistry and Biology, Univ. of Potsdam; Maulbeerallee 2 DE-14469 Potsdam Germany
| |
Collapse
|
10
|
Becher MA, Grimm V, Thorbek P, Horn J, Kennedy PJ, Osborne JL. BEEHAVE: a systems model of honeybee colony dynamics and foraging to explore multifactorial causes of colony failure. J Appl Ecol 2014; 51:470-482. [PMID: 25598549 PMCID: PMC4283046 DOI: 10.1111/1365-2664.12222] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 01/10/2014] [Indexed: 12/03/2022]
Abstract
A notable increase in failure of managed European honeybee Apis mellifera L. colonies has been reported in various regions in recent years. Although the underlying causes remain unclear, it is likely that a combination of stressors act together, particularly varroa mites and other pathogens, forage availability and potentially pesticides. It is experimentally challenging to address causality at the colony scale when multiple factors interact. In silico experiments offer a fast and cost‐effective way to begin to address these challenges and inform experiments. However, none of the published bee models combine colony dynamics with foraging patterns and varroa dynamics. We have developed a honeybee model, BEEHAVE, which integrates colony dynamics, population dynamics of the varroa mite, epidemiology of varroa‐transmitted viruses and allows foragers in an agent‐based foraging model to collect food from a representation of a spatially explicit landscape. We describe the model, which is freely available online (www.beehave-model.net). Extensive sensitivity analyses and tests illustrate the model's robustness and realism. Simulation experiments with various combinations of stressors demonstrate, in simplified landscape settings, the model's potential: predicting colony dynamics and potential losses with and without varroa mites under different foraging conditions and under pesticide application. We also show how mitigation measures can be tested. Synthesis and applications. BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee colony dynamics.
BEEHAVE offers a valuable tool for researchers to design and focus field experiments, for regulators to explore the relative importance of stressors to devise management and policy advice and for beekeepers to understand and predict varroa dynamics and effects of management interventions. We expect that scientists and stakeholders will find a variety of applications for BEEHAVE, stimulating further model development and the possible inclusion of other stressors of potential importance to honeybee colony dynamics.
Collapse
Affiliation(s)
- Matthias A Becher
- Environment & Sustainability Institute, University of Exeter, Penryn Campus Penryn, Cornwall, TR10 9FE, UK ; Rothamsted Research West Common, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Volker Grimm
- UFZ, Helmholtz Centre for Environmental Research - UFZ Permoserstr. 15, 04318, Leipzig, Germany ; Institute for Biochemistry and Biology, University of Potsdam Maulbeerallee 2, 14469, Potsdam, Germany ; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig Deutscher Platz 5e, 04103, Leipzig, Germany
| | - Pernille Thorbek
- Environmental Safety, Syngenta, Jealott's Hill International Research Centre Bracknell, Berkshire, RG42 6EY, UK
| | - Juliane Horn
- UFZ, Helmholtz Centre for Environmental Research - UFZ Permoserstr. 15, 04318, Leipzig, Germany
| | - Peter J Kennedy
- Environment & Sustainability Institute, University of Exeter, Penryn Campus Penryn, Cornwall, TR10 9FE, UK ; Rothamsted Research West Common, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Juliet L Osborne
- Environment & Sustainability Institute, University of Exeter, Penryn Campus Penryn, Cornwall, TR10 9FE, UK ; Rothamsted Research West Common, Harpenden, Hertfordshire, AL5 2JQ, UK
| |
Collapse
|
11
|
Becher MA, Osborne JL, Thorbek P, Kennedy PJ, Grimm V. Towards a systems approach for understanding honeybee decline: a stocktaking and synthesis of existing models. J Appl Ecol 2013; 50:868-880. [PMID: 24223431 PMCID: PMC3810709 DOI: 10.1111/1365-2664.12112] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 04/22/2013] [Indexed: 01/26/2023]
Abstract
The health of managed and wild honeybee colonies appears to have declined substantially in Europe and the United States over the last decade. Sustainability of honeybee colonies is important not only for honey production, but also for pollination of crops and wild plants alongside other insect pollinators. A combination of causal factors, including parasites, pathogens, land use changes and pesticide usage, are cited as responsible for the increased colony mortality.However, despite detailed knowledge of the behaviour of honeybees and their colonies, there are no suitable tools to explore the resilience mechanisms of this complex system under stress. Empirically testing all combinations of stressors in a systematic fashion is not feasible. We therefore suggest a cross-level systems approach, based on mechanistic modelling, to investigate the impacts of (and interactions between) colony and land management.We review existing honeybee models that are relevant to examining the effects of different stressors on colony growth and survival. Most of these models describe honeybee colony dynamics, foraging behaviour or honeybee - varroa mite - virus interactions.We found that many, but not all, processes within honeybee colonies, epidemiology and foraging are well understood and described in the models, but there is no model that couples in-hive dynamics and pathology with foraging dynamics in realistic landscapes.Synthesis and applications. We describe how a new integrated model could be built to simulate multifactorial impacts on the honeybee colony system, using building blocks from the reviewed models. The development of such a tool would not only highlight empirical research priorities but also provide an important forecasting tool for policy makers and beekeepers, and we list examples of relevant applications to bee disease and landscape management decisions.
Collapse
Affiliation(s)
- Matthias A Becher
- Rothamsted Research, West Common Harpenden, AL5 2JQ, UK ; Environment & Sustainability Institute, University of Exeter Cornwall Campus, Penryn, TR10 9EZ, UK
| | | | | | | | | |
Collapse
|