Introduction
Interpretation of the Terms of Reference
Bee health encompasses a holistic view, relying on several key characteristics at the colony level The assessment of a managed honeybee colony's health status is guided by the Terms of Reference (TOR) 1, which outlines a hierarchical approach At the top of this hierarchy are three main concepts that capture the multidimensional aspects of: (i) the managed honeybee colony itself; (ii) its habitat and management practices; and (iii) its productivity in relation to human interests, collectively known as 'colony attributes.'
The article discusses the assessment of three overarching concepts through various abiotic and biotic components known as 'indicators' and 'factors' Indicators relate to colony attributes and outputs, while factors are linked to external drivers These elements reflect the overarching concepts and can be derived from measuring specific variables For example, 'queen potential fecundity' serves as an indicator of 'queen presence and performance', informed by variables such as viable egg-laying, drone production, new queen cell counts during swarming, and mating success Additionally, TOR2 highlights the biological significance of these indicators and factors in evaluating the health of managed honeybee colonies, providing a ranking for their technical feasibility and priority for inclusion in field surveys across the EU.
Each indicator is defined by one or more variables, quantified through specific methods TOR3 evaluates the suitability and availability of these methods for estimating colony health status across Member States However, detailed protocols and validation of various test methods are essential for harmonized implementation throughout the EU The outputs from TOR2 and TOR3 will enable comparisons of managed honeybee colony health data across different European regions and support the creation of a unified data model, facilitating data merging and meta-analysis at both national and European levels.
TORs 1–3 outline the current understanding of indicators and factors affecting bee health, while TOR4 focuses on future guidance for planning field surveys It references documents that assist in designing data collections and offers advice on analyzing field data to assess the health status of managed honeybee colonies The scientific opinion emphasizes the importance of defining the survey's objective, selecting appropriate data analysis methods, and carefully designing and executing data collection Various output types are discussed, along with key characteristics of relevant analysis methods, providing an overview of existing techniques and essential considerations for effective data collection.
Target audience
Understanding the effects of various indicators and factors on bee health necessitates simultaneous data collection from multiple geographical areas, which is complicated by the diverse nature of the European apicultural sector and environmental conditions This scientific opinion outlines tools for assessing bee health, contributing to EFSA’s goal of an integrated risk assessment approach Enhancing test method validation and data analysis across the EU will support national and European risk assessment bodies in evaluating bee health The guidance offers harmonized tools for data analysis and comparison, allowing flexibility in measurement protocols Beekeepers are crucial in field data collection and are a primary audience for this paper, which aims to instruct them on submitting data to the scientific community Key elements of field survey design and data analysis are discussed, emphasizing the need for a multidisciplinary approach to assess bee health comprehensively Additionally, linking new and existing open databases with reliable information on bee health will enhance transparency in risk assessment and support management and decision-making processes at various levels.
The health status of a managed honeybee colony can only be evaluated indirectly, as its characteristics are integral to overall productivity This productivity, viewed from a human perspective, can also be assessed through both direct and indirect methods.
A set of factors is used to assess the external drivers
A set of indicators is used to assess the colony attribute
A set of indicators is used to assess the colony outputs LEVEL 3 Variables
Measurable quantities identified for each indicator and factor One or more variables are used to estimate each indicator or factor
Practical procedure to quantify the variable One or more methods are available to estimate the same variable
This scientific opinion aims to overview tools for assessing bee health, contributing to EFSA's goal of developing an integrated risk assessment approach for bees The identified methods will enhance data collection harmonization on bee health across Europe, enabling more robust analysis amid various stressors and changing environmental conditions Further actions are necessary to convert this information into a detailed study protocol and to validate practical test methods aligned with specific objectives.
The toolbox outlined in this scientific opinion is designed for all stakeholders involved in measuring, reporting, and analyzing bee health in the EU It will assist the EFSA MUST-B working group in selecting indicators for assessing pesticide effects on bee health and in designing field surveys for data collection Additionally, the findings may aid risk assessors and scientists in conducting epidemiological studies to explore associations between various factors, particularly in large geographic areas While the paper is not a practical guide for maintaining healthy honeybee colonies, it encourages beekeepers to contribute data for scientific analysis, fostering their involvement in research and risk assessment However, the implementation of the proposed methods may be hindered by their time-consuming nature and the need for specialized training, potentially limiting data collection to trained beekeepers and inspectors.
Improving our understanding of the factors influencing bee health will enhance support for beekeepers and farmers, ultimately optimizing honey production and pollination services This scientific opinion is valuable for various stakeholders, each with distinct goals Chapters 3 to 6 outline the available tools, while Chapter 7 details their application for different groups Beekeepers and bee inspectors play a crucial role in data collection and reporting, with other stakeholders also seeking high-quality data Accurate models require precise data to produce outputs that accurately represent real-world conditions.
This scientific opinion evaluates the health status of managed honeybee colonies (Apis mellifera) in Europe, as this species is the focus of most existing knowledge and techniques While the current tools are primarily designed for honeybees, they may also be adaptable for other bee species Expanding the analysis to include diverse bee species is essential, given their critical role in providing pollination services.
Data and methodologies
Hierarchical approach
2.1.1 Identification of the overarching concepts of a managed healthy honeybee colony
The Panel on Animal Health and Welfare (AHAW) has established a framework to evaluate the health status of managed honeybee colonies, similar to the five freedoms framework used for assessing the welfare of farmed animals This scientific opinion is based on key overarching concepts and is supported by a comprehensive review of the scientific literature conducted through Web of Science.
4 This scienti fi c opinion does not aim to review the current knowledge on bee health, or to provide guidance to the scienti fi c community on future research activities.
5 http://www.welfarequality.net/everyone/26559/7/0/22
This approach efficiently identifies key concepts, indicators, and factors without conducting detailed literature reviews, as the goal is not to provide a comprehensive overview of all scientific evidence for each element A workshop with approximately 50 participants was held to uncover scientific evidence overlooked by the working group, as detailed in the event report available at the EFSA website.
• TOPIC: (bee) AND TOPIC: (ecosystem) AND TOPIC: (review) Timespan: 2000–2015 Search language=Auto
The key multidimensional traits of a well-managed honeybee colony were outlined and served as a foundation for discussions among multidisciplinary expert groups, specifically the HEALTHY-B and MUST-B working groups A healthy managed honeybee colony was characterized, leading to the identification of three overarching concepts.
2.1.2 Identification of indicators and factors
This paper identifies key indicators and factors based on data collected from field surveys and expert contributions Various data sources were consulted to enhance the research findings.
• national or international bee health monitoring programmes – EPILOBEE, BeeNet, APENET, German Bee Monitoring Project, COLOSS project (e.g Bee Book), UK’s Bee Health programme 7 ;
• publications identified using searches described in Section2.1.1;
• Web of Science using the search string‘honeybee*’AND health AND monitoring, 2000–(March)
• publications and/or scientific reports of projects or working groups provided by experts, in particular papers published between March 2015 and June 2016.
Beekeeping practices vary significantly between Europe and other regions, such as the United States, where colony movement is more intensive Consequently, the review of scientific documents focused specifically on the European context, excluding reports like the US monitoring program BEEinformed However, studies from outside the EU are considered when evaluating indicators or factors, provided their context is relevant to the European situation.
The article presents an overview of identified indicators and factors derived from field surveys, which were utilized to create mind maps illustrating colony attributes, external drivers, and outputs These mind maps are structured according to life-history theory (Fabian and Flatt, 2012) and emphasize energy and material budgets as fundamental drivers of physiological processes within a colony Additionally, the mind maps incorporate measurable indicators and factors under experimental conditions, providing a comprehensive toolbox for selecting relevant indicators and factors tailored to specific objectives such as field surveys, risk assessments, or modeling.
2.1.3 Identification of variables and methods
Key indicators and factors were identified through a review of scientific literature and consultations with bee experts and professionals from related fields The primary methods were outlined, with experts selecting the 'preferred' method based on its effectiveness for harmonization and application in multifactorial field surveys across various Member States.
Procedure for selection of indicators and factors
2.2.1 Procedure and scoring system used
After identifying the key indicators and factors, each was assigned a functional definition (Figure 2) These indicators and factors were evaluated for their relevance to the health status of managed honeybee colonies, receiving either a high or low score (refer to Table 2 for definitions) Only those with a high relevance score were further analyzed for their technical feasibility in multifactorial field surveys, also rated as high or low (see Table 2 for definitions).
7 https://www.gov.uk/guidance/bee-health (last accessed 1 June 2016).
In field surveys, only indicators and factors with high technical feasibility scores were evaluated for their priority of inclusion, categorized as high, medium, or low (refer to definitions in Table 2) The results are detailed in the main text (TOR2 in Sections 3.2, 3.3, and 3.4) and presented in comprehensive tables in Appendix B.
Indicators and factors with an H-HH score, indicating high relevance, high technical feasibility, and high priority, were evaluated in TOR3 Each indicator or factor was characterized by identifying a specific variable for field surveys, aimed at ensuring harmonization and comparability of data across various Member States in Europe The detailed outcomes of this analysis are presented in Sections 3.2, 3.3, and 3.4 of the main text.
Identification of indicator/factor jndicator j
Functional or operational definition TOR2
Scoring relevance, technical feasibility and priority
Figure 2: Approach followed to select indicators and factors (TOR2) and to identify and analyse methods that could be used to measure and report the selected indicators and factors (TOR3)
Table 2: Criteria and descriptions used in the assessment of bee health indicators/factors
Relevance to assessing the health status of a managed honeybee colony (indicators)
Relevance to understanding the context of a managed honeybee colony (factors)
High There is robust scientific evidence suggesting an association of the indicator/factor with bee health
Low There is no or little scientific evidence suggesting an association of the indicator/factor with bee health
The hyphen distinguishes the score related to bee health relevance, which remains constant regardless of the study objective, from the scores assessing technical feasibility and priority for field survey inclusion, which may fluctuate with changes in the study objective.
2.2.2 Data collection in field surveys
To achieve a comprehensive risk assessment of bee health as outlined in EFSA’s MUST-B project, it is essential to implement EU-wide monitoring that encompasses all aspects of bee colonies, including external influences and outputs EFSA (2014) recommended either conducting a large-scale multifactorial field survey across various Member States over several years or integrating data from smaller, concurrent surveys Given the unlikelihood of a new pan-EU monitoring initiative in the near future and the existence of ongoing national surveys, it is more efficient to harmonize indicators, factors, and methods to enable the merging of national datasets for meta-analysis While each Member State can maintain its specific survey objectives, utilizing a common toolbox will enhance data exchange and facilitate result comparisons, which is currently challenging.
The AHAW Panel prioritizes large field surveys in its mandate to ensure that selected tools are applicable throughout the EU These surveys are fundamental procedures designed to gather data for a better understanding of health.
Technical feasibility infield survey High Measurement of the factor/indicator is or could be routinely applied by a beekeeper within the context of a
field survey Low Measurement of the factor/indicator cannot or could not be routinely applied by a beekeeper within the context of afield survey
NA Not applicable because not assessed
Priority indicator/factor infield survey
Experts emphasize that the benefits derived from the data collected on the indicator or factor significantly outweigh the resources invested Furthermore, this indicator or factor holds substantial relevance for the majority of Member States across various conditions.
Experts assess the data collection ratio for indicators/factors as medium when the benefits outweigh the resource efforts, particularly in certain Member States or regions Conversely, this ratio is deemed low when the benefits are minimal compared to the resources required, with relevance limited to a few Member States or very specific conditions.
NA Not applicable because not assessed (a): Referring, among others, to geographical, climatic, environmental or beekeeping management conditions.
Table 3: Combinations of scores used for the selection of indicators/factors to be measured in a
Score Relevance to assessing colony attributes
(indicators) or external drivers (factors)
Priority indicator/ factor infield survey
L Low Not assessed Not assessed
The H-HH score is highlighted in green, indicating that the associated indicators and factors will be included in TOR3, while others will not The assessment of a honeybee colony's status and its variations over time and space is conducted through various methods, including observations, measurements, and interviews The AHAW Panel does not establish a typology for field surveys or design specific surveys, allowing flexibility for Member States to utilize the toolbox in ongoing surveys with differing objectives, resources, and sampling capacities Nonetheless, the Panel provides considerations related to the design and implementation of surveys.
• the problem formulation: in general terms or from specific perspectives;
• the spatial and temporal extent and resolution of the study to develop;
• the variability of the sampling variables and the precision of the estimates required for the analyses.
It is advisable to measure various indicators and factors at least three times a year: after winter, during summer, and before winter Workshop participants suggested using the flowering of Salix spp to determine the timing of the 'after winter' inspection, although no supporting publications were found An alternative approach is to utilize 'cumulative day degrees' to standardize the start of the beekeeping season across the EU, as this method accounts for regional differences More frequent data collection is encouraged to enhance the dataset, with the timing of measurements tailored to the survey's objectives Additionally, it is recommended that two individuals collect data from each hive—one to inspect and the other to document observations.
It is essential to focus on the various stakeholders involved in data collection during field surveys, ensuring they are well-informed about the objectives and rationale behind the research.
The field survey protocol outlines the frequency of honeybee colony inspections, emphasizes the use of standardized sampling and measurement methods, and addresses reporting methods along with data protection concerns It is essential that at least two different stakeholders participate in the process to ensure comprehensive and reliable results.
Beekeepers play a vital role in managing bee colonies year-round and are essential for providing the necessary information and data for field surveys To ensure accurate data collection and reporting, it is important for beekeepers to receive specialized training.
Inspectors or operators play a crucial role in supporting beekeepers by collecting specific samples and data for surveys They may also participate in sample collection and analysis based on the survey's objectives and the local beekeeping organization Appointed by the survey coordination team, these trained individuals ensure consistent data collection across various colonies, apiaries, and regions.
Workshop
Involvement of hearing experts and the organization of a bee health workshop were crucial for TOR1–3, as they helped identify relevant scientific evidence overlooked by the Working Group (WG) and clarified ambiguous points in the draft text Announced on the EFSA website in December 2015, the workshop attracted around 55 interested experts, with 30 selected based on eligibility criteria, alongside 20 direct invitations to other experts, including WG members Held on 13–14 April 2016, the workshop featured breakout sessions addressing various chapters of TOR1–3, facilitating detailed discussions on participant comments deemed relevant by the WG An event report is available on the EFSA website, and the gathered information was utilized by the WG to finalize the draft scientific opinion.
9 https://www.efsa.europa.eu/it/supporting/pub/1055e (last accessed 11 July 2016).
Assessment
Identi fi cation of the colony attributes, external drivers and colony outputs (TOR1)
3.1.1 Characteristics of a managed healthy honeybee colony
A managed honeybee colony, defined as a population of Apis mellifera maintained by a beekeeper with a specific queen, is considered a new colony if the queen is replaced, either naturally or by the beekeeper, due to the resulting genetic changes A review of scientific literature and discussions among working group members and experts from various stakeholders led to the conclusion that certain characteristics define a healthy managed honeybee colony.
• an adequate 10 size, demographic structure and behaviour in relation to the annual life cycle of the colony and the geographical location;
• an adequate 9 production of bee products in relation to the annual life cycle of the colony and the geographical location;
A healthy honeybee colony is characterized by three main concepts: colony attributes, external drivers, and colony outputs Colony attributes indicate the health status of the managed honeybee colony, while external drivers influence this health and the colony's productivity The production of bee products and the provision of pollination services are crucial, as they motivate beekeepers to manage their colonies effectively Further definitions and relationships between these concepts can be found in Sections 3.1.2–3.1.4 and illustrated in Figure 3.
Indicators like Varroa destructor and molecular markers such as vitellogenin may serve as predictive markers for winter survival in honeybee colonies To validate their effectiveness as health markers across Europe, it is essential to gather data on these indicators, which could lead to their future inclusion as characteristics of a healthy managed honeybee colony.
Five colony attributes have been distinguished that should be analysed when assessing the health status of a honeybee colony (Figure3):
Section 3.2 details each colony attribute, accompanied by mind maps that provide an overview of the identified indicators These indicators are evaluated based on their relevance to each colony attribute, as well as their technical feasibility and priority for implementation in field surveys.
Three different external drivers have been distinguished (Figure3):
Section 3.3 outlines each external driver, accompanied by mind maps that provide a comprehensive overview of the identified factors These factors are evaluated based on their relevance to each external driver, as well as their technical feasibility and priority for implementation in a field survey.
10 Suf fi cient to complete the annual life cycle at a given location.
The managed honeybees contribute significantly to the ecosystem by providing essential services This opinion focuses on two primary ecosystem services directly linked to these honeybees.
• the pollination services provided by the honeybee colony in terms of regulating ecosystem services (= regulating service);
• the products harvested by the beekeeper, the hive rental service and the live honeybees extracted from the honeybee colony in terms of provisioning ecosystem services (=provisioning service).
Section 3.4 details the colony outputs, accompanied by a mind map that provides an overview of all identified indicators These indicators are evaluated based on their relevance to the colony outputs, technical feasibility, and priority for implementation in field surveys.
Colony attributes re fl ecting the health status of a managed honeybee colony (TOR2 – 3)
honeybee colony (TOR2 – 3) 3.2.1 Queen presence and performance 3.2.1.1 Identification of indicators related to queen presence and performance (TOR2)
Assessing the health of a managed honeybee colony requires analyzing the queen's presence and performance, as these factors significantly impact the colony's size, structure, and survival The indicators for measuring the queen's presence and performance were identified through a specific methodology, with detailed information available in Appendix B, Table B.1 The following paragraph highlights the key indicators, especially those that received high scores.
(i) Relevance of queen presence and performance indicators to the bee health status of a colony
The survival of a colony is heavily dependent on the presence of a queen, as her absence or inability to produce offspring can jeopardize the colony's health (Winston, 1991) High rates of queen mortality or the replacement of queens, such as through supersedure, may signal underlying health issues within the colony or indicate that the queens being produced are of poor quality (Page and Peng, 2001) The age of the queen plays a crucial role in her reproductive capacity, influencing the likelihood of her replacement (Tarpy et al., 2000) A healthy queen should be capable of laying a sufficient number of viable fertilized and unfertilized eggs, maintaining appropriate ratios of workers to drones, and adhering to seasonal laying rates.
In a multidimensional assessment of managed honeybee colony health, it is essential to consider various factors, including colony attributes (represented in blue), external drivers (depicted in green), and colony outputs (illustrated in orange).
Potential fecundity also involves assessing the queen's mating success, specifically whether she mated with enough males during her mating flight This factor is crucial as it influences the colony's vigor and survival (Fyg, 1964; Tarpy et al., 2013; Mattila and Seeley, 2014).
(ii) Technical feasibility and priority to include queen presence and performance indicators relevant to bee health infield surveys
The assessment of indicators related to bee health revealed that direct analysis of queen mortality is not feasible for routine field surveys due to the difficulty in locating deceased queens and the common practice of replacement before normal mortality occurs The presence and fecundity of the queen are crucial indicators of both queen and colony health, influencing demographic stability and survival Beekeepers can evaluate these factors during regular hive inspections Additionally, the queen's longevity, linked to her age, is significant for assessing fecundity and indirectly indicates mortality; this information is easily recorded by beekeepers, especially when queens are marked Maintaining records of queens per hive aids beekeepers in monitoring natural queen replacement, or supersedure, which may signal health issues if it occurs at unusually high rates.
3.2.1.2 Methods and tools to measure indicators related to queen presence and performance (TOR3)
Table4 provides an overview of different variables and methods to measure the indicators
Monitoring the presence of a queen, potential fecundity, natural queen replacement (supersedure), and queen longevity are essential practices for beekeepers during routine hive inspections Labeling the queen aids in tracking her age and timely replacement It is advisable to collect data on these indicators at least three times annually: after wintering, during the active beekeeping season, and before wintering The following text evaluates the variables and methods related to the H-HH indicator, recommending the most suitable approaches for field surveys For comprehensive details on the suggested methods, refer to Appendix C (Tables C.1–C.3), which aims to enhance their standardization across Member States.
To confirm the presence and vitality of a queen bee in a colony, visually inspecting the hive combs is essential Marking the queen enhances her visibility, making it easier for beekeepers to identify her, which is why this practice is strongly advised.
H-HH, indicators with a High link with bee health, High technical feasibility and High priority; H-HL, indicators with a High link with bee health, High technical feasibility and Low priority; H-L, indicators with a High Link with bee health and Low technical feasibility; !, recommended variable to assess the corresponding indicator The score H-HH is highlighted in green as the indicators with this score are taken forward in TOR3, whereas the other indicators not.
In beekeeping, the presence of the queen can be confirmed through visual detection, but if she is not visible, the sighting of young eggs (1–3 days old) serves as an alternative indicator of her presence Ideally, beekeepers should aim to both visually spot the queen and observe young eggs to ensure a healthy hive.
To evaluate the queen's potential fecundity, it is essential to qualitatively assess the various stages of worker brood—eggs, larvae, and pupae—present in the hive, as this reflects the queen's fertility and the colony's ability to rear viable offspring While visually spotting the queen during egg-laying is less effective due to the challenges of hive inspection, a healthy, well-mated queen should consistently produce viable eggs, resulting in a solid brood pattern For a more precise determination of the queen's mating success, microsatellite analysis is necessary, though this is typically limited to research environments.
Labelling the queen bee and maintaining accurate records are essential for determining her age Beekeepers can easily mark a new, unlabelled queen using number tags or paint pens, a process that takes only a few minutes Utilizing international code colors can simplify age identification (Human et al., 2013), but diligent record keeping is also crucial During each hive inspection, beekeepers should verify whether the previously marked queen is still present or if she has been replaced by an unmarked queen Any queen replacements should be documented accordingly.
If regular queen replacement by the beekeeper takes place regardless of status/performance/age of current queen, this variable is no longer meaningful.
To assess queen longevity and natural queen replacement, it is essential to label the queen and maintain accurate records Natural queen replacement, or supersedure, should be reported as the number of new queens identified over a two-year period, excluding those introduced by the beekeeper It is advisable to label new queens as previously mentioned Additionally, any replacement of the queen by the beekeeper must be documented, as frequent replacements prevent the colony from exhibiting natural supersedure, rendering this variable insignificant.
Table 4: Measurement of selected indicators on queen presence and performance
Indicator Variable [unit] (a) Method (a) Presence of a queen Visual detection of the queen [Y/N]
Visual verification by checking through combs and in the walls of the hive
Detection of fresh eggs [Y/N] Visual verification of presence of 1-day-old eggs Potential fecundity Queen laying viable worker eggs [Y/N]
Qualitative visual identification of worker pupae, larvae and eggs
Queen laying viable worker eggs [Y/N]
Visual identification of the queen laying
Longevity of a queen Age of the queen [months] Queen labelling and record keeping Natural queen replacement (supersedure)
Colony rate of queen replacement [number of supersedure queens/2 years]
Queen labelling and record keeping
Key variables, methods, and implementation timing for field surveys across the EU are highlighted in green and can be conducted by beekeepers at least three times a year: after winter (1-2 weeks post-foraging start, before the first major nectar flow), during the active summer season, and before winter preparation More frequent data collection is encouraged to enhance the dataset, as discussed in the 'sampling frame' section The specific timing of measurements should align with the objectives of the field survey, with detailed methods outlined in Tables C.1 – C.3.
3.2.2 Demography of the colony 3.2.2.1 Identification of indicators related to demography of the colony (TOR2)
Honeybees undergo four life stages: egg, larvae, pupae, and adult The adult bees consist of three castes: the queen, drones, and workers The queen's primary role is to lay eggs, while drones mate with queens from other colonies, contributing to the local bee population but not directly benefiting their own colony Worker bees handle most colony tasks, with younger workers performing in-nest duties and older workers taking on outside tasks Healthy honeybee colonies exhibit specific demographic indicators that influence their size, structure, and survival Analyzing these indicators is essential for assessing colony health, as survival is determined by multiple factors measured over time.
‘demography’indicators, in particular those with high scores.
Relevance of demography indicators to bee health
Brood demography is crucial for understanding the survival and development of bee colonies, as it reflects the future population of bees within a hive The quantity of brood follows an annual cycle and is essential throughout the colony's development, except during queen succession, certain winter periods, and extreme summer heat in regions like southern Europe Additionally, the consistency of the brood pattern, known as brood solidness, is an important qualitative measure; a 'spotty' brood, characterized by more than 10% empty cells, indicates potential issues with brood quality, which may stem from factors such as low sperm quality or disease.
External drivers affecting the health status of a managed honeybee colony (TOR2-3)
The external drivers are defined as overarching concepts that reflect the multidimensional characteristics of the colony habitat and management They can only be assessed indirectly.
The Resource Providing Unit (RPU), as defined by Gilioli et al (2014), encompasses the environmental components essential for resource generation and regulation for a honeybee colony The RPU's shape and area are determined by the foraging distance of the colony's honeybees, typically assumed to be circular with the hive at its center, although variations may occur based on landscape features like large water bodies The RPU's structural characteristics, such as crop positioning and size, along with its functional aspects, including pollen productivity, offer insights into the resource availability, type, quantity, and accessibility for the colony.
Indicator Variable [unit] Method Implementation Timing (a)
P larvaewith clinical signs (disease) in the hive [yes/no]
P larvaethrough PCR (conventional and real-time PCR) on diseased larvae (in the presence of clinical signs)
Each time clinical signs are observed
Lateralflow device test Beekeeper/inspector Each time clinical signs are observed Presence of
P larvaewithout clinical signs (infection) in the hive [yes/no]
P larvaethrough PCR (conventional and real-time PCR) on honey/adult bees/ debris (in the absence of clinical signs)
After winter, during summer, before winter
P larvaewith or without clinical signs (infection) in the hive [yes/no]
Identification of spores or bacilli ofP larvaethrough microscopy
Each time the identification ofP larvaeis required. Can also be done after bacterial culture After winter, during summer, before winter
Isolation ofP larvaeand morphological identification of bacterial colonies through culture methods
Each time the identification ofP larvaeis required. After winter, during summer, before winter
Mass spectrometry and biochemical tests are essential in the laboratory for the identification of P larvae This identification process is necessary after winter, during summer, and before winter.
Identification ofP larvae using antibody-based techniques
Laboratory After winter, during summer, before winter
The methods most suitable for implementation in fi eld surveys across the EU are highlighted in green.
Data collection for bee foraging should occur 1-2 weeks after winter, during the active summer season, and before winter preparation More frequent measurements are recommended to enhance the dataset, with timing based on the field survey objectives Homogeneous areas, or patches, should be identified for resource production, as average foraging distances can indicate habitat quality and resource availability, which varies with colony size Research estimates an average foraging distance of 3 km and a maximum of 10 km from the hive.
The RPU significantly affects in-hive products, making it essential to consider RPU information when assessing bee health indicators This section highlights the RPU indicators, focusing on those that achieve high scores.
3.3.1.1 Relevance of the RPU factors to the bee health status of a colony
The RPU is influenced by various factors, including productivity, land cover, environmental contamination, and agronomic practices For a detailed overview, refer to Appendix B, Table B.6, which provides a comprehensive list of RPU factors along with their corresponding variables.
Land cover/use significantly influences the RPU by affecting the availability of forage in both quantity and quality According to Eurostat's Concepts and Definitions Database (2016), land cover refers to the observable (bio)physical characteristics on the earth's surface, including vegetation (such as trees, bushes, fields, and lawns), bare soil, hard surfaces (like rocks and buildings), and wet areas or bodies of water The term "observed" indicates that land cover can be assessed through various observation methods, including the human eye, aerial photographs, and satellite sensors.
Whereas‘the land use is characterised by the arrangements, activities and inputs people undertake in a certain land cover type to produce, change or maintain it’(Fao, 1999).
Land cover and use define the foraging area surrounding the colony, highlighting the habitat's surface and its role in indicating the relative availability of various food sources and resources within the RPU.
H-HH, factors with a High relevance to bee health, High technical feasibility and High priority; H-HM, factors with a High relevance to bee health, High technical feasibility and Medium priority; H-HL, factors with a High relevance to bee health, High technical feasibility and Low priority; H-L, factors with a High relevance to bee health and Low technical feasibility; L, factors with a Low relevance to bee health; !, recommended variable to assess the corresponding indicator The score H-HH is highlighted in green as the factors with this score are taken forward in TOR3, whereas the other factors not.
Figure 10: Mind map resource providing unit–identified factors and corresponding scores
Kandziora et al (2013) evaluated four spatially explicit land use data sets to determine their effectiveness for assessing ecosystem services in a specific region The study concluded that a crop-level spatial resolution is essential for accurately evaluating provisioning ecosystem services.
In this paper, the land cover/use is considered in terms of habitat and resources (forage) provided to the bees.
Agronomic practices encompass various farming types, crop management, and pest control methods, which can significantly impact honeybee health Cropping practices, such as crop rotation and pre-flowering grazing, may limit crop diversity within a region, thereby affecting the forage available to honeybees and potentially compromising colony survival during winter Additionally, the use of chemical pest control methods, particularly insecticides, poses risks to bee health, although this discussion does not aim to list specific compounds The intensity of agricultural practices, influenced by farming types like monoculture or organic farming, also plays a crucial role Furthermore, the productivity of pollen, nectar, and honeydew within the region is vital for maintaining honeybee colony health, as deficiencies in these resources can adversely affect the bees.
An analysis of the primary food sources within the RPU and the hive can provide insights into the colony's ability to forage, store, and utilize feed effectively.
Contaminated bee forage, air, and puddle water are critical environmental factors to consider when assessing colony health Contamination refers to the presence of harmful substances, such as pesticides, in the habitats of honeybee populations The primary route of pesticide exposure for bees is through the oral uptake of contaminated nectar High pesticide residues in nectar can lead to colony death, while contaminated pollen negatively impacts larval development and nurse bees Additionally, honeydew, a sugar-rich secretion from aphids and scale insects, is collected by honeybees and transformed into honey.
Contaminated honeydew poses significant risks to bee colonies, particularly when insecticides are applied to crops infested with aphids, adversely affecting foraging bees (Maurizio, 1985; Hagenbucher et al., 2014; EFSA, 2013) Additionally, air exposure through pesticide drift is a critical concern (Marzaro et al., 2011; Girolami et al., 2012) Bees often prefer drinking from puddles, which tend to have higher contaminant concentrations near treated crops compared to general surface water, making this environmental factor crucial for honeybee colony health (EFSA, 2012a).
The yellow-legged hornet, Vespa velutina, first identified in France in 2005, has since spread across Western Europe, posing a significant threat to beekeepers and leading to increased colony losses It is essential to collect data on the presence of Vespa velutina to monitor its impact effectively.
field surveys in affected areas.
Birds, mammals, and most insects can affect bee colonies by preying on bees, damaging hives, or consuming food supplies, but they do not cause diseases and are not reliant on the honeybee life cycle As such, they are viewed as external factors in beekeeping Although the effects of these animals on European beekeeping are not extensively documented, experts believe their impact is relatively minor.
3.3.1.2 Technical feasibility and priority to include RPU factors infield surveys The land cover/use
For characterising and describing the land cover at the EU level, the CORINE Land Cover (CLC,
2006) defined at three levels might be sufficient, whereas for an assessment at a local or Member
Colony outputs (TOR2-3)
3.4.1 Relevance of colony outputs to the bee health status of a colony
As indicated in Section3.1 a managed honeybee colony is considered healthy when the following end points are achieved:
• it has an adequate size, demographic structure and behaviour in relation to the annual life cycle of the colony and the geographical location;
• it has an adequate production of bee products in relation to the annual life cycle of the colony and the geographical location;
The last two end points are considered outputs provided by the bee colony in terms of ecosystem service provision, as represented in Figure13.
The outputs of a bee colony reflect its contribution to the ecosystem, as defined by the Millennium Ecosystem Assessment (2005), which emphasizes the benefits humans derive from the environment This discussion focuses on the services provided by managed honeybees, specifically highlighting the two primary ecosystem services that are directly influenced by their activities.
Bee products serve as an ecosystem provisioning service, while the pollination service provided by bees acts as an ecosystem regulating service To assess the health of a managed honeybee colony, it is essential to measure outputs related to both provisioning services—such as harvested products, hive rental services, and live honeybee production—and regulating services, particularly pollination The primary objective of a beekeeping enterprise is to generate marketable outputs, which include honey, pollen, bee bread, propolis, wax, jelly, and venom, as well as live honeybee production, such as queens and nucleus colonies.
Pollination is a crucial ecosystem service that significantly impacts crop production and the health of non-crop plants, as well as landscape aesthetics This article focuses specifically on the pollination services provided by honeybees to both cultivated and wild plants, while acknowledging that the assessment of landscape aesthetics and other indirect benefits is complex and beyond the scope of this discussion Honeybees play a vital role by visiting a diverse array of plants, enhancing biodiversity and agricultural productivity.
H-HH, service with a High relevance to bee health, High technical feasibility and High priority; H-HM, service with a High relevance to bee health, High technical feasibility and Medium priority !, recommended variable to assess the corresponding service The score H-HH is highlighted in green as the factors with this score are taken forward in TOR3, whereas the other factors not.
The mind map outputs indicate that various factors significantly contribute to pollination services within the colony, highlighting their importance for overall colony health Measuring pollination services across multiple plants in the landscape can serve as a reliable indicator of colony vitality, as weaker colonies tend to provide limited pollination, often focusing on high-yield crops Additionally, foraging preferences can influence activity levels and may change over time and between different apiaries, which should be considered when assessing pollination service provision.
The decline in pollinator populations is a significant concern, as it directly impacts the provision of essential ecosystem services (Bos et al., 2007) The degradation of native habitats for bees adversely affects agricultural productivity by diminishing pollination services (Foley et al., 2005) A review by Liss et al (2013) emphasizes the necessity of a clear definition of pollination ecosystem services, advocating for the comparison of various quantitative measures To effectively evaluate these services within the RPU, a comprehensive definition that encompasses all relevant factors is essential.
• the pollination service provided by the managed honeybees needs to be assessed for both the crops and wild plants that benefit from insect pollination;
• the land cover, plant phenology and plant and flower density, the flower characteristics in terms of their attractiveness to bees and the need for cross-pollination.
The weather conditions should be taken in account, because the weather influences pollination as well as human activity.
3.4.2 Technical feasibility and priority to include colony output indicators relevant to bee health status in field surveys
Beekeepers routinely measure various variables related to provisioning services, which can be easily collected during field surveys The quantity of honey harvested from a hive serves as a significant indicator of this service, relevant to all Member States and under most conditions In comparison, the amounts of pollen, royal jelly, and propolis present in a colony at any given time are relatively small.
2010) For this reason, it is not recommended that these be measured in largefield surveys.
Measuring the provision of regulating services by honeybee colonies is often impractical due to the time and expertise required for fieldwork in most evaluation methods Various pollinators contribute to pollination services, and under natural conditions, accurately assessing the specific role of honeybees is challenging.
If there is adequate data on hive locations, it is advisable to use and evaluate modeling approaches with medium priority While modeling methods can connect honeybee colony placement to pollination services, the lack of information regarding the effects of colony health on these services hinders precise modeling of health impacts on pollination (see Becher et al., 2014).
3.4.3 Methods and tools to measure factors related to colony outputs Provisioning service
Bee colonies produce various products, including honey, bee bread, propolis, and royal jelly Honey is stored in the hive's brood chamber and, when space is limited, in the super While beekeepers primarily harvest honey from the super, bees can consume it if necessary Estimating the honey quantity in the super can be done by weighing it before and after harvesting, a common practice among beekeepers to assess total colony production Alternatively, the quantity can be estimated by weighing the empty super before installation and subtracting this weight from subsequent measurements For hives with multiple supers, all weights should be summed to determine the total honey quantity Using a queen excluder between the brood chambers and the super enhances accuracy by preventing brood presence in the super combs If brood or pollen is found in the super, their weight should be estimated and subtracted from the total.
To accurately associate honey production with the respective hive, it is advisable to label supers with the hive number Various methods exist for estimating honey quantity in both the hive body and supers, including digital image analysis and visual estimation While the super primarily contains honey, there are instances where the queen may lay eggs in the lower section, necessitating surface area calculations In cases where the super is solely filled with honey, weighing it can be more straightforward than employing photographic methods or grids The difference in weight between a full and empty super indicates the total honey harvested.
The floral resources in the RPU are evaluated based on nectar and pollen productivity To measure these resources in the landscape, four steps are essential: first, count the number of open flowers in each habitat at a specific time; second, sample the nectar, which includes assessing both water and energy content; third, collect pollen samples; and finally, extrapolate the data to gain a comprehensive understanding of floral resource availability.
To quantify pollination service provision, it is essential to compare the pollination demand of plants with the pollination effectively supplied by bees at the RPU level (Schulp et al., 2014a) Pollination demand refers to the number of visits needed by flowers, adjusted for the number of flowers that require pollination to achieve economically viable crop production or maintain stable populations of wild plants In contrast, pollination supply is defined as the total number of visits to flowers within a given RPU.
Estimating pollination demand requires an analysis of land cover and the phenological stage of plants within the relevant planning unit (RPU) To assess pollination supply, it is essential to evaluate the number of pollinated flowers, taking into account factors such as crop yield, plant fitness, pollen transfer, and pollinator visitation A review by Schulp et al (2014b) highlights the ongoing discussion regarding the roles of honeybees and wild pollinators in providing essential pollination services.
In measuring pollination demand, two types of methods are distinguished:
In measuring pollination supply, three types of methods are distinguished:
– sampling pollinator visitors to determine the proportion of visits by the focal taxa,
– conducting pollination assessments to determine deficits;
Appendix C(Section3.2) provides details on these measuring methods and includes their protocols,strengths and weaknesses, and existing data sets.