Varroa mite

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Control Tools

  • Diagnostics availability

  • Commercial diagnostic kits available worldwide

    Pathogen detection

    Standardised methods for Varroa destructor detection are available (WOAH).Different veterinary medicinal products can be used for diagnosis and control of V. destructor, which can lead to residues in hive products, according to the mode of use and the characteristics of the active ingredients.

    Disease diagnosis

    Different recommendations for detection in different countries:

    • Counts of natural mite fall on sticky bottom boards (mainly in Mid/ Northern Europe).
    • Analysis of adult bee samples collected by “ether roll” method in USA, powder sugar shake method in USA and Europe, or alcohol washing in Australia and Europe.
    • Advantage of the powder sugar method: it can be performed on live bees that can be returned to the hive after the assessment.

    Determining threshold levels within the “Monitoring project” and “Tolerance breeding project” in Germany, and EU funded SMARTBEES project, National Bee Unit in UK has a Varroa calculator, advising when to treat based on a number of parameters.

    - https://www.nationalbeeunit.com/diseases-and-pests/varroa/; and a similar calculator for Germany is the “Varroawetter” - https://www.dlr.rlp.de/C1256EA7002BE0CB/0/10BD68B53277ACCBC1257B9B0035A22D

    PCR-based methods are available to detect and quantify Varroa-associated viruses, but hardly usable for routine diagnosis.Treatments that can be used during the honey flow (e.g., formic acid, or other organic compounds) are required in some countries.

    GAPS :

    Pathogen detection

    Detection level and its relationship with the real mite population, even considering colony size and amount of brood.

    Disease diagnosis

    The need of diagnosis is required for treatment purposes. Damage thresholds are dependent on :

    • Bee density (population)
    • Amount of capped brood
    • Geographical regions & climate
    • Time of the year
    • bee species and subspecies
    • Varroa-resistance of the bees
    • Varroa haplotype
    • Beekeeping management practices
    • Virus load (type and quantity; there is a need to define thresholds for discrimination between covert and overt infections.

    Development and description of a standardised method (Dietemann et al., 2013):

    • Bottom board (used by beekeeper for treatment decision)
    • Adult bee samples
    • Bee brood
    • virus load (virus diversity and quantification of viruses)
    • Synergies between the different factors.

    There is a need to verify the treatment efficacy and to go more in deep on their toxicity (especially chronic) for the bees and synergy with other bee diseases. Efficacy and toxicity are evaluated before a veterinary medicinal product is authorised.Moreover, V. destructor mites may develop resistance to some of the active substances over time and this should be periodically ascertained, e.g., through bioassays to identify phenotypic resistance or DNA-based assays to identify mutations known to be associated with resistance.There is still a need to revise and improve Integrated Pest Management programmes and ensure that they are specific to the local conditions (climate, honey flow, Varroa dynamics, previously occurring Varroa-resistance phenomenon).

  • Diagnostic kits validated by International, European or National Standards

    No kits but only methods are available (WOAH).

  • Diagnostic method(s) described by International, European or National standards

    OIE Manual of diagnostic tests and vaccines for Terrestrial Animals (WOAH).

    Varroosis is a EU listed disease of honey bees, the National Reference Laboratory has to approve the diagnostic methods and adopted treatments. Notifiable status is varying among the countries.

    GAPS :

    Varroosis is a listed disease of honey bees at the EU level (Commission Delegated Regulation (EU) 2018/1629). However, national regulations are not harmonised.

    Depending on the epidemiological situation of each member state, the veterinary services and competent authorities should be involved in the development of control strategies. However, in most member states veterinarians are not properly trained on varroosis and in some member states this is left to the responsibility of stakeholders, i.e., the beekeepers. Advice is sometimes provided by the veterinary services, but they do not always have the time to do this specifically for apiculture.Treatment success is dependent on a good treatment strategy, which has to be adapted to the local conditions of the different countries.

  • Commercial potential for diagnostic kits in Europe

    V. destructor is a quite large mite that is easily detectable by direct observation. However, when beekeepers usually diagnose the parasite by eye, infestation levels are already too high: low infestation levels may not be easily detected and a diagnostic kit to diagnose its presence could be very useful. There would be a market if the price is low and the test is not time consuming.

    GAPS :

    Varroa mite infestation is endemic worldwide (It has been detected also in Australia in 2022). However, there are still some very small Varroa-free territories in the EU.A tool to assess the colony status is needed: i.e., immunity, stress, viruses and Varroa loads.A tool to test the efficacy of treatments, possible Varroa pharmaco-resistance and genetic resistance of the bee to Varroa is also needed.Varroa pharmaco-resistance should be ascertained periodically to verify efficacy of treatments, e.g., via bioassays to identify phenotypic resistance or DNA-based assays to identify mutations known to be associated with resistance.However, the adoption of good beekeeping practices and proper biosecurity measures, as well as proper beekeeper education to diagnose and control Varroa are probably needed more than a new test.

  • DIVA tests required and/or available

    Not applicable.So far, no vaccination is available.

    GAPS :

    There are three territories in Europe that are classified Varroa-free: Åland Islands, FIN (2013), Isle of Man, UK (2015) and six islands of Azores Archipelago PT (2019). The Animal health law still considers this condition and it is up to the member states working to achieve or to maintain a Varroa-free status in some territories.

  • Vaccines availability

  • Commercial vaccines availability (globally)


    GAPS :

    Knowledge gap on honey bee immunity.There are some approaches (RNAi), however, these approaches still represent “a matter for research” with doubtful chances for success.Trans-Generational Immune Priming, TGIP where you “vaccinate” the queen and she transfers immunity to the offspring is a promising technique that obtained the first results in the control of American foulbrood. A vaccine has been registered in the USA (2022; for first field tests only).

  • Marker vaccines available worldwide


  • Effectiveness of vaccines / Main shortcomings of current vaccines

    Not applicable.

  • Commercial potential for vaccines in Europe

    High! Varroa is the main problem for beekeeping worldwide.

    GAPS :

    Uncertainty of innovative research.So far, no really promising new approach is available, except RNAi.Trans-Generational Immune Priming, TGIP where you “vaccinate” the queen and she transfers immunity to the offspring is a promising technique.Information on Varroa biology and physiology and host-parasite relationship has been obtained through the SMARTBEES project. However, research is still required.

  • Regulatory and/or policy challenges to approval

    Not applicable.General problem of the application of vaccines within the beehive (obviously not for RNAi). Oral administration would be most recommended.

  • Commercial feasibility (e.g manufacturing)

    None.So far, even the first step is lacking.

  • Opportunity for barrier protection


  • Pharmaceutical availability

  • Current therapy (curative and preventive)

    Several types of treatment are available.

    Regulatory approved products (VMP):

    • Synthetic pyrethroids (mostly used as strips);
    • Coumaphos (trickling and as strips);
    • Amitraz (strips and fumigation). Widely used in the commercial “beekeeping industry”;
    • Organic acids: formic acid, oxalic acid;
    • Essential oils: mainly thymol-based products, some other substances with potential.

    The list of regulatory approved products varies from country to country (see Mutual Recognition and Decentralised Procedure-Veterinary), but is mostly based on the same few active ingredients.Biotechnical methods can play an important role in controlling the Varroa infestation in a honey bee colony (beekeeping management strategies: drone brood removal, total brood removal, queen caging + treatment), especially used in and integrated approach to boost the final efficacy of the chemical treatments. This allow to improve efficacy and, in the same time, to reduce the quantity of the chemical used at the apiary level.

    GAPS :

    Veterinary medicinal products are available in many countries in Europe. Where needed, the cascade system can be used in agreement with the national competent authorities. Imports of medicinal products from elsewhere in the EU or third countries permitted, if the need can be justified. New regulation on veterinary medicinal products is available (Regulation (EU) 2019/6).

    The range of veterinary medicinal products availability depends on the country. However, the continued Varroa challenge may not be a result of poor medicine availability, but the lack of correct use or failure to implement IPM strategies.Frequently medicines are sold to beekeepers without the need of any veterinary prescription. Even administration of medicines to the honey bees is provided without a direct control of veterinarians. Harmonisation is needed in Europe.Training for a proper Varroa control is pivotal for veterinarians, advisors and beekeepers.

    Home-made treatments are very frequent in apiculture. More controls on the sector are needed.Honey bees are still considered to be a ‘minor species’ but all due measures should be taken as for other food producing animals.The regulatory framework for application for approval of new medicinal products is still considered difficult, time-consuming and expensive at the EU and national levels by companies and beekeepers. However, in recent years, several new veterinary medicinal products intended for Varroa mite control have been approved in the EU with the centralised procedure, even if no new active ingredients have been identified. The MUMS (=Minor Use Minor Species) approach was intended to increase the facilitation for registering new medicines also for honey bee diseases.

    Mutual recognition has been often indicated as a fast and easier way for veterinary medicines authorization in other member states. Unfortunately, this is not always true.

    Furthermore, a guideline on veterinary medicinal products (in particular on their efficacy and safety) controlling V. destructor parasitosis in bees is now available at https://www.ema.europa.eu/en/veterinary-medicinal-products-controlling-varroa-destructor-parasitosis-bees-scientific-guideline

    Anti-Varroa treatments are affected by several parameters concerning the final efficacy they are able to provide, including the climatic conditions and the amount of brood that is in the colony;

    • Synthetic pyrethroids: more information on mode of action and on the dynamic of mite resistance is necessary. “Easy to apply” resistance test is required. Prove whether a “resistance and residue management” with the beekeeper is feasible.Several references are available on this topic, even for other high environmental impact synthetic compounds.
    • Coumaphos: More information on mite resistance is required. Removal of residues from beeswax is not possible. Studies should be needed to verify development of Varroa resistance induced by persistence of residues in the wax recycling.
    • Amitraz: APIVAR and APITRAZ are available in some EU countries. Ensure that there is wider registration and approval of the products.
    • Organic acid: influence of the temperature and humidity on the efficacy. Formic acid is the only acaricide that is able to kill mites within the sealed brood cells but may be toxic for honey bees (especially brood and queen bees).

    Considering all the above, veterinary prescription could be mandatory for honey bee veterinary medicines guaranteeing traceability of veterinary medicines.Costs could be reduced considering the involvement of one (or few) veterinarians at level of beekeeping organizations.

  • Future therapy

    Integrated treatment: biotechnical strategies & chemical treatment.Avoidance of negative selection of parasites by reducing the use of pharmaceuticals: resistant Varroa mites.

    GAPS :

    A better knowledge of the biology and behaviour of Varroa could help developing new treatments or improve the application of already existing treatments.Biological control should be more investigated.Interaction with other stress factors (e.g., environment, beekeeping management) should be integrated in the new treatment development & strategy.An integrated Varroa research project should be developed at the EU level through a framework (probably with regional differences, North, Central and South Europe) able to identify the better strategies for adopting proper biosecurity measures to control Varroa mite infestation, prioritizing beekeeping techniques and reducing the use of high environmental impact active ingredients.

  • Commercial potential for pharmaceuticals in Europe

    If controls on the proper use of the medicines at the apiary level is not improved, commercial potential for pharmaceuticals is limited, because many active ingredients are commercially available at lower costs compared to the authorised medicines. Many beekeepers still prefer to use the raw active ingredient instead of the authorised medicine to save money.

    Commercial potential may be higher in case of effective products, “easy to apply”.However, beekeeping is a difficult market with most hobby and side-line beekeepers. An exact analysis of the potential of the market is difficult.

    GAPS :

    Authorised veterinary medicines are not always available and are frequently not cheap, even considering that nowadays Varroa control needs a more frequent number of treatments than in the past. A proper answer from the Pharmaceutical Industry seems too late to get in relation to the needs of the sector.More effective veterinary controls on the use of the medicines at the apiary level should be implemented and harmonized.Pharmaceutical industry is afraid of raw active ingredients purchased at lower cost by beekeepers from chemical suppliers, even if authorised medicinal products are available. This could lead to less profit for the pharmaceutical industry, but in the same time to higher risks of pharmaco-resistance, toxicity to the bees and residues in hive products.Moreover, it should be considered that cost for the registration of veterinary medicine in EU is really high.A stand-alone development of a new chemical entity exclusively for Varroa treatment does not seem to be commercially justifiable due to the high investment in pharmaceutical (e.g. toxicological, etc.) studies.Encourage chemical testing for Varroa control.A more systematic approach for testing new chemical (especially natural/organic compounds) products on bees for Varroa control would be an improvement.

  • Regulatory and/or policy challenges to approval

    The registration procedure is considered a challenge for the pharmaceutical companies despite the fact that in general more attention is now devoted to this sector, even considering the relevance that bees have on the environment and biodiversity.There are many obstacles for the approval of new pharmaceuticals, mainly due to the relatively small market; for pharmaceutical companies, an investment in the beekeeping sector represents a high financial risk.

    GAPS :

    Even if bees are MUMS the number of anti-Varroa treatments for each hive is not little along the year.

    Most efficient veterinary controls concerning the use of the veterinary medicines at the apiary level will imply a higher amount of medicines bought by beekeepers. The side effect of paying higher costs to guarantee bee health could be reduced almost completely using EU funds foreseen for the beekeeping sector. This could provide more realistic information concerning the number of hives treated (updating the national register) and avoid a negative reaction from beekeepers.

    Shorter procedures should be further considered for this sector (MUMS). The registration procedures are well defined: centralised, decentralised, mutual recognition and national. Decentralised/centralised as well as mutual recognition applications will ensure harmonisation across EU Member States. Scientific advice regarding marketing authorisation applications can be sought from national competent authorities or the European Medicines Agency.Centralised agreement at the EU-level is recommended.Reduce the costs for the procedure to get approved products and/or increase protection periods.

  • Commercial feasibility (e.g manufacturing)

    Yes. Active ingredients are usually of low cost and the authorised veterinary medicines are not complex.Good.

    GAPS :

    Companies do not consider this sector a priority despite the significant demand from the sector for new medicines and the relevance of honey bees for the environment and biodiversity.Industry afraid of product piracy (limited intellectual property protection/insufficient data protection periods/active ingredient already available as plant protection product at lower price).

  • New developments for diagnostic tests

  • Requirements for diagnostics development

    Detection of mite population with a threshold level of damage (e.g., by genetic markers) is strongly needed.Almost all honey bee colonies in the EU are infested with Varroa mites therefore, quantitative diagnostic tools are required to better understand the level of infestation, the damages Varroa is causing to the bees and the time for treatments.An evaluation of damage thresholds for different regions/seasons is required.Diagnostic tools should fulfil the following requirements:

    • Reliable estimate of infestation rates.
    • Easy to apply.
    • Standardised.

    Bee pathology, pesticides impact, immunological system.

    GAPS :

    Diagnostics of “PMS” (parasitic mite syndrome) including associated pathogens (bee viruses) could be helpful for the prevention of damages/timing of treatment, depending on the Varroa infestation level.

  • Cost of developing new or improved diagnostics and their validation

    Less than for developing new chemical treatments but still significant: field tests are required during several years and several locations in Europe, for validation.

    GAPS :

    The use of easy and cheap methods and active ingredients is also easily copied.Beekeepers could easily apply at the apiary level.

  • Research requirements for new or improved diagnostics

    Genetic markers.See section “Time to develop new or improved diagnostics”. The validation of such techniques under controlled conditions should be performed in different climatic regions, at different apiaries (variation of bee colonies, honey bee subspecies, mite population dynamics) and minimum 2 years.

    GAPS :

    Identification of specific genes related to Varroa infestation.

  • Technology to determine virus freedom in animals

    Methods are available for the diagnosis of all honey bee viruses associated with Varroa, but not all are validated.


    GAPS :

    There is the need to develop and to validate protocols for the detection and quantification of more honey bee viruses associated with Varroa.Identification of biomarkers for honey bees exposed to different viruses as a consequence of Varroa infestation.More monitoring on the course of infection and pathogenesis of bee viruses required. There is a need to define thresholds for discrimination between covert and overt viral infections. This is a relatively “young” field of research.

    A better understanding of the microbiome of the bee could offer a new way to interpret the bee health status. Some studies on this topic are already available.

  • New developments for vaccines

  • Requirements for vaccines development / main characteristics for improved vaccines

    Development of vaccines: Identification and isolation of Target proteins of V. destructor, Identification of immune-relevant genes in bees.Trans-Generational Immune Priming (TGIP) where you “vaccinate” the queen and she transfers immunity to the offspring is a promising technique.

  • Time to develop new or improved vaccines

    From 3-5 years up to 10 years?

  • Cost of developing new or improved vaccines and their validation

    > € 4 million

  • Research requirements for new or improved vaccines

    Innovative research.

  • New developments for pharmaceuticals

  • Requirements for pharmaceuticals development

    Ideally requirements for pharmaceuticals should be:

    • highly effective;
    • very limited toxicity to honey bees;
    • cheap;
    • no side effects;
    • limited pollutant effect on honey bee products (honey and beeswax in particular);
    • no pharmaco-resistance;
    • not dangerous for the user;
    • easy to apply.

    All applications should be tested under different (e.g. climatic) and defined conditions so far, this is not defined in detail.New medicine for Varroa treatment are needed.It is needed defining the position/role of a new veterinary medicinal product within the Varroa control strategy (e.g., applied to brood right or broodless colonies).

    GAPS :

    Knowledge about Varroa has much improved during the last 20 years. However, it is still present worldwide (detected in several operations and locations in Australia in 2022). (See also section “Current occurrence/distribution).Clear and universally valid definition of tests for efficacy, side effects, workload, etc. of new products (and of some existing applications like formic acid).EU guidance available at https://www.ema.europa.eu/en/veterinary-medicinal-products-controlling-varroa-destructor-parasitosis-bees-scientific-guideline

    Most applications are limited for the use outside the period of the honey flow (which is, at the same time, the period of increased mite population) due to the risk of residues in honey applications during the brood season are available depending on the active ingredient (even with lower efficacy if compared with treatment during brood less periods).Develop an integrated system: integrate the biological aspects of the colony and the Varroa-population with the use of biotechnical methods and veterinary medicines in order to reduce the use of chemicals.New compounds with new modes of action.Feasible benefit risk assessment (residues in honey, honey market requirements, risk for the user). Persistent acaricide residues in beeswax are still a problem (Old combs are melted, beeswax recycled in new foundations and residues cannot be removed).

  • Time to develop new or improved pharmaceuticals

    4-5 years was the time length in the 80s.Improvement of existing applications (especially on organic acids and essential oils) could be done within 3-5 years.10 to 15 years if the research starts from scratch today.

    GAPS :

    A more intensive cooperation with respective companies as well as academia is required for new acaricides (and new active compounds).

  • Cost of developing new or improved pharmaceuticals and their validation

    New compound: € 30 - 50 million.New pharmaceutical (formulation) compound: few million euros.Clinical development & regulatory approval: few million euros.

    GAPS :

    A different model is needed: cost sharing.The new acaricide compounds discovered by the scientific community should be systematically tested for Varroa treatment.Create an awareness for the Varroa market for the decision making of developing new treatments.

  • Research requirements for new or improved pharmaceuticals

    Screening of new acaricide substances, new application methods and strategies, even integrated with other control measures taking into account the following parametres: time of the year, colony development, bee density, colony strength, climate, virus population.

    More detailed knowledge is needed on:

    • mite biology/physiology;
    • mite population dynamic during the beekeeping season in the geographic area;
    • damage thresholds (see above).

Disease details

  • Description and characteristics

  • Pathogen

    Varroa destructor (Anderson and Truman, 2000), mite (Mesostigmata: Varroidae).Several bee viruses are associated to Varroa. Most of them increase their virulence if Varroa mite infestation is concomitant. Varroa mite is able to favour activation and transmission of certain viruses.

    GAPS :

    Not all viruses are known, including their impact on honey bee health.

    The importance of the interaction and transmission between Varroa and other non-viral infections is not fully known.

  • Variability of the disease

    Varroa destructor in Europe, America.Varroa jacobsoni in Asia.Different haplotypes.V. destructor types with differences in virulence identified (e.g. Korean, Japan haplotypes), pesticide resistant strains, different virulent virus strains (e.g. DWV more virulent after multiplication in the parasite).Different genotypes/ haplotypes available, however in Europe only one “virulent” haplotype present.Different response to the parasite byhoney bee species (e.g., Apis mellifera/Apis cerana) and subspecies (e.g., Apis mellifera capensis/Apis mellifera intermissa) or hybrids (e.g., africanized honey bees).

    GAPS :

    Cooperation between the original location of Varroa (Asia) and Europe should be better developed. Proof of pathogenesis of different Varroa haplotypes.The factors of virulence of different Varroa strains are unknown.More in deep studies should be done to verify different responses of the honey bees to the parasite.

  • Stability of the agent/pathogen in the environment

    Obligate parasite, cannot survive without the host.Cannot survive without honey bees for more than 2 weeks.

  • Species involved

  • Animal infected/carrier/disease

    Reproduction only on honeybees Apis mellifera and Apis cerana (in wasps a rare vagrant).

  • Human infected/disease


  • Vector cyclical/non-cyclical


  • Reservoir (animal, environment)


  • Description of infection & disease in natural hosts

  • Transmissibility

    Yes, from bee to bee and drifting.Yes, from comb to comb and from colony to colony. Re-infestation is very frequent. Especially from collapsed/untreated colonies to strong, robbing colonies. Re-infestation after treatment is an issue.Can be easily transmitted between colonies of the same apiary and transmitted over the flight range (2-3 km) through robbing, swarming or drifting.Transport of colonies, migratory beekeeping & beekeeping management practices.

    GAPS :

    More studies on re-infestation and its management/prevention should be carried out.

  • Pathogenic life cycle stages

    Brood infestation (Varroa reproduction occurs at this stage within capped brood cells), adult bee infestation.All ontogenetic stages of the mite (protonymph, deutonymph, adults) are haematophagous. Adult Varroa mites feed primarily on honey bee fat body tissue (Ramsey et al., 2019).

  • Signs/Morbidity

    Clinical signs detectable in case of severe infestation (PMS).Mainly overt symptoms of the associated bee viruses (DWV, ABPV, CBPV, IAPV); weakening of the colony and reduction in productivity.

    GAPS :

    Differentiation of the effect of damages by the parasite itself and the associated bee viruses is difficult with the naked eyes.A tool to measure and discriminate the origin of the symptoms (Varroa or viruses) and the thresholds for viral load according to time of the year would be needed.

  • Incubation period

    Varroosis: 1 year (1 beekeeping season) or less.From first infestation to mortality 1-3 years (depending on invasion pressure, honey bee genetics and virus levels).

  • Mortality

    Almost 100% if not properly treated.

  • Shedding kinetic patterns

    Not applicable.

  • Mechanism of pathogenicity

    Honey bee fat body tissue feeding, haemolymph deprivation, co- infections (viruses)Damage of fat body tissue of adult honey bees and loss of haemolymph, mainly during the ontogenetic development of the bee,weakening of immune system, weakening of the colony, depopulation/damages/collapse.Loss of haemolymph reduces the lifespan of the bees and the reproduction success of the drones.Virus infections favoured and colony weakening.

    GAPS :

    Interaction with stress factors such as other pathogens, chemical compounds used for controlling Varroa infestation and toxic substances (e.g., phytoterapeutic products), environmental conditions (nutrition availability), bee management (feed administration, beekeeping techniques), climate, colony behaviour and genetics.Definition of the infestation level thresholds and “tipping point” between damage of individuals and visible/measurable damage of the colony as a superorganism.

  • Zoonotic potential

  • Reported incidence in humans


    GAPS :

    Not Applicable.

  • Risk of occurence in humans, populations at risk, specific risk factors


    GAPS :

    Not applicable.

  • Symptoms described in humans


    GAPS :

    Not applicable.

  • Likelihood of spread in humans


    GAPS :

    Not applicable.

  • Impact on animal welfare and biodiversity

  • Both disease and prevention/control measures related

    No direct impact on vertebrate animals.Reduction of pollination activity, negative impact on quality and quantity of crop production, plant and animal biodiversity & sustainability in general.

  • Endangered wild species affected or not (estimation for Europe / worldwide)

    No impact on wild bees, but potential impact on wild plant and animal biodiversity & sustainability.

    GAPS :

    Limited knowledge on the true impact of Varroa on wild bee species, if any.Limited knowledge on the impact on wild species potentially affected.

  • Slaughter necessity according to EU rules or other regions

    In the EU no instructions on the destruction of infested honeybee colonies. Treatment is recommended and is under the responsibility of Member States competent authority. EU rules on animal health consider V. destructor infestation from the point of view of animal movement (i.e., existing Varroa-free territories need to be protected).According to Italian veterinary regulation revised in 2013 and now under revision following Regulation (EU) 2016/429, in case of severe infestation with evident clinical signs and lack of proper management, destruction of the colony is applicable.

    GAPS :

    According to the characteristics of the infestation a harmonisation of the rules is recommended.A protocol for hive destruction is needed, as well an evaluation of the economic damage linked on the loss of biodiversity (needed to define refunding measures, if any).

  • Geographical distribution and spread

  • Current occurence/distribution

    Worldwide, so far present even in New South Wales (Australia), still not reported in the rest of Australia and some parts of Oceania. Few free areas in Europe (Åland Islands, north of Sweden, Isle of Man (UK) and six islands of Azores Archipelago (Portugal)) and central Africa.

    GAPS :

    Distribution in some rural areas (e.g., Africa) is still unknown.

  • Epizootic/endemic- if epidemic frequency of outbreaks

    Panzootic, well established parasitic disease.Endemic in Europe.

  • Speed of spatial spread during an outbreak

    Present in all colonies but re-infestation after treatment is a key point.Spread is linked to honey bee (adult or brood) movement (natural or human managed), ability in preventing/controlling the disease, and beekeeping techniques adopted.Cases of re-infestation are frequent; untreated/collapsing colonies and abandoned apiaries are a great danger. May be higher via disoriented (e.g., because of pesticides) and drifting bees.

    GAPS :

    A crucial problem nowadays seems to be the spread of “natural beekeeping”, where no treatment approach is foreseen.

  • Transboundary potential of the disease

    High.Already worldwide distributed, limitation of spread is very difficult, nearly impossible.

  • Route of Transmission

  • Usual mode of transmission (introduction, means of spread)

    Migratory beekeeping, drifting, swarming, robbing, balancing colonies (moving combs and bees from one colony to another) and other beekeeping techniques.Between colonies/between apiaries robbing, movement of bees and material by beekeeper.Viruses may spread via honey bees and mites.

    GAPS :

    Identify beekeeping techniques able to reduce the risk of transmission of mites.

  • Occasional mode of transmission

    Trade of honey bee colonies (worldwide).

  • Conditions that favour spread

    Wrong beekeeping management: trade, movement of infested colonies, ineffective Varroa control, lack of treatment against Varroa (e.g., natural beekeeping).Bee colonies dying of high mite population followed by robbing, drifting.Bee density and average infestation rates are the main driver for transmission.

    GAPS :

    Drifting phenomena should be better understood as entities and consequences.

  • Detection and Immune response to infection

  • Mechanism of host response

    Limited knowledge.Leaving colonies untreated (the “Bond test”: live or let die) resulted in success in South Africa, but it is unthinkable in practice because of too high losses in terms of honey bee health and productivity.Varroa induces a suppression of the innate humoral immune system of the host by (i) introduction of salivary gland secretion into the puncture site and (ii) transmission of bee viruses.

    GAPS :

    More information needed about host-parasite interaction.Immune response is almost a black box (individual – honeybee level and colony level).Different level of host resistance depending by the bee species, subspecies/genotype.

  • Immunological basis of diagnosis

    Not available.“DNA-Chip” for Virus diagnostic (EU-project BEEDOC).

    GAPS :

    Tools should be available to measure immunological status of honey bees and subsequent disturbance by stress.

  • Main means of prevention, detection and control

  • Sanitary measures

    Regular treatment to prevent too high Varroa infestation loads in the colonies.Colony movement only with low infested colonies.

    GAPS :

    Control strategies need to be harmonised and controls on them improved by authorities.

  • Mechanical and biological control

    Beekeeping techniques need to be combined with medicinal treatments (IPM approach).Biotechnical control is possible and may include: splitting of colonies, trapping Varroa in capped brood, total brood removal, drone brood removal, or brood interruption (e.g. queen caging in summer or winter to prevent the queen from egg laying).

    GAPS :

    So far, no biological control is available.Biotechnical control should be improved to reduce the use of the medicines at the apiary level, according to geographical, climatic conditions, bee genetic and beekeeping equipment.

  • Prevention through breeding

    Several research groups are working to produce honey bees that are resistant or tolerant to Varroa mites.

    GAPS :

    More efforts in supporting research should be done in this direction.

  • Diagnostic tools

    Monitoring natural mite mortality, assessment of Varroa infestation levels (e.g., on adult honey bees or bee brood).

    GAPS :

    Predicting the need of control (treatment), check the effectiveness of the control measures.

  • Vaccines

    Not applicable.

  • Therapeutics

    Pharmaceutical treatments (essential oils, organic acids, synthetic substances have a pivotal relevance (see above).

    GAPS :

    Treatments are complex. They should be applied at the same time with beekeeping techniques able to reduce the amount of chemical used at the apiary level and able to improve the final acaricide efficacy.There is some concern about Varroa resistance, especially for high environmental impact substances. More treatment options should be developed, especially focused on organic compounds (essential oils, natural products). Hive management should be improved, together with beekeeper skills, biosecurity measures and good beekeeping practices).The efficacy of some Varroa control strategies is climate-dependent to some extent and may affect quality of hive products and resistance development in Varroa. Therefore, the knowledge of beekeepers and veterinarians should be adequate and continuously updated on a year to year basis.

  • Biosecurity measures effective as a preventive measure

    Biosecurity measures have a crucial relevance in preventing and controlling Varroa infestation.Varroa infestation level should be monitored on a large scale. Treatments should be coordinated at local/regional level.Honey bee movement restrictions are not able to prevent Varroa spreading if colonies are not previously properly treated.Natural beekeeping or abandoned apiaries may expose to a high risk other hives/apiaries: it is well documented how weak dying colonies can strongly favour the spread of mites (robbing by stronger colonies).

    GAPS :

    Lack of awareness of the importance of the Varroa infestation level (above a threshold).Even if treatments should be efficiently coordinated at a local/regional level, this is frequently neglected by beekeepers’ associations or Veterinary Services. Free-living honey bee colonies/unmanaged colonies/natural beekeeping/abandoned apiaries could act as a source for re-infestation.A monitoring of the infestation-rate at regional level could be helpful to make the beekeepers aware about the need for treatments.

  • Border/trade/movement control sufficient for control

    All colonies are infested but their infestation level should be always under control.Heavily infested colonies should be properly managed (pharmacological treatments should be applied, no moving of the hive, including destruction in the worst cases).

    GAPS :

    Regulation is lacking on diseased colonies that should not be moved. Indication should be provided concerning different Varroa threshold levels.Specific EU regulations on colony movement do exist to protect Varroa-free territories.

  • Prevention tools


    GAPS :

    Information to beekeepers should be better organised (disease alerts) at a local scale and promoted at a European level.

  • Surveillance

    Varroa is distributed worldwide (even in Australia, Varroa is now present in New South Wales).The need for control (treatment) activities is well known.Some national/regional monitoring/surveillance programs consider varroosis (German bee monitoring, Italian control program). The veterinary services monitor Varroa infestation levels analysing several samples per year (mostly from collapsed or damaged colonies), supervising the program implementation, and recommending the best actions to adopt.

    GAPS :

    A long term, extensive surveillance, followed by a well defined and standardised protocol is still lacking. It is now considered in the EU Animal Health Law. Colonies and beekeepers should be registered in each EU country (National beekeeping registry) (Commission Delegated Regulation (EU) 2019/2035. Recording of movements should also be mandatory and applied.

  • Past experiences on success (and failures) of prevention, control, eradication in regions outside Europe

    No eradication experiences available. However, an attempt of eradication was done when Varroa mite was first detected by New South Wales (NSW) Department of Primary Industries (DPI) in surveillance hives at the Port of Newcastle on 22 June 2022: biosecurity zones were established and the National Varroa mite Emergency Response Plan put in place. On the 10th of January 2023 109 Infected Premises in NSW were confirmed. NSW DPI continues to fight Varroa mite incursion with teams testing, tracing, carrying out surveillance, and euthanising affected hives (www.dpi.nsw.gov.au/Varroa) in the attempt to eradicate it.Varroa is considered a minor problem in South Africa, as well as in South America. The latter thanks to the presence of Africanised bees.Even in Asia, Varroa is considered a minor problem on Apis cerana.Means of Varroa control around the world are similar to those applied in Europe (similar success and failure experience).Climatic conditions could affect the level of infestation and the effectiveness of the control measures.Since 2006, Varroa was listed among the causes of Colony Collapse Disorder (CCD) in the USA. No completely effective treatment able to guarantee mite eradication is available. Border controls concerning (honey bee free areas are currently done in North America.Some efforts trying to eradicate Varroa were made in Eastern and Northern Europe around 50 years ago (for instance in the former Czechoslovakia), when the parasite arrived, with no success and difficulties for beekeepers to understand the strategies.

    GAPS :

    For effective control of Varroa several problems: registered acaricides available but their efficacy depends on several factors, i.e., colony strength, climate, mode of application, colony management, need for tools to measure efficacy and impact on honey bee biology.

  • Costs of above measures

    The economic impact of good control and surveillance systems is crucial.Varroa treatment costs per hive and per year are minimum € 5.00. There are 15 million colonies in the EU. Total estimated costs: at least € 75 million.20% of colonies die every year, mainly because of Varroa. At least € 200 are needed to replace a colony = estimated costs of at least € 600 million per year in EU.

    GAPS :

    Cost should include not only the colony loss, but even the purchase of a new colony for replacement, lack of harvest and pollination services. How can we estimate the cost of the lack of biodiversity?

  • Disease information from the WOAH

  • Disease notifiable to the WOAH


  • WOAH disease card available


  • Socio-economic impact

  • Zoonosis: impact on affected individuals and/or aggregated DALY figures

    Not applicable.

  • Zoonosis: cost of treatment and control of the disease in humans

    Not applicable.

  • Direct impact (a) on production

    Yes, honey bee colony losses could be due to Varroa infestation if not properly treated/managed.About an average value of colony losses of 20% per year is due to Varroa. About € 200 are needed to replace a colony = € 600 million per year.Pollination fees should be calculated too.Estimation of honey production: 160 thousand tons per year in the EU. Mean honey price is € 6 / kg. Loss of 20% of the colony = 32 thousand tons = € 192 million.Current UK price for honey in bulk is about £ 6 per kg = 8 Euros.There is a shortage of beeswax (for pharmaceutical, food, apiculture sector): the demand is higher than the production. Prices have doubled in the past 2 years.

    GAPS :

    The honey distributed on private/local networks is not taken into account in cost estimations, and the additional workload for livestock recovery as well.

  • Direct impact (b) cost of private and public control measures

    Varroa treatment per hive per year is minimum € 5; € 4-10 according to More et al. (2017). There are 15 million colonies in the EU. Total costs: € 75 million.20% of colonies are lost every year due to mainly Varroa. € 200 to replace a colony = € 600 million per year.The EU invests € 32 million each year for helping the beekeeping sector = € 64 million in total (top up of 50% financial help for each member state).

    GAPS :

    Costs of state surveillance programs should be included.

  • Indirect impact

    Reduction and/or disruption of honey production.Lack of pollination of wild plants and agricultural plants as well as of their quali-quantitative production.Organic honey producers need to adopt more time-consuming strategies and may have some difficulties in controlling Varroa, experiencing subsequent higher costs and decreased honey production.Decrease in number of beekeepers.Fewer colonies for pollination.Loss in biodiversity.Tropical apiculture has less problems with Varroosis control.

    GAPS :

    There are difficulties to assess the extent of these impacts. There are also difficulties to assess the costs of these impacts.Honey bees are generally considered to be major pollinators, essential for optimal crop and fruit quali-quantitative production but data on their relative contribution versus other pollinating insect species is limited.Loss of genetic diversity in honeybee (e.g., breeding programs) must be kept into consideration too.

  • Trade implications

  • Impact on international trade/exports from the EU

    No big impact because of the worldwide distribution of Varroa mites. It can be high in case of high numbers of imports.

  • Impact on EU intra-community trade

    Limited, since Varroa is present in all EU countries and Apis mellifera is the main bee species. Varroa is distributed worldwide. Only Åland Islands (FIN), Isle of Man (UK) and Azores (PT) are officially Varroa-free territories in Europe.

  • Impact on national trade


    GAPS :

    Specific EU and international regulations on colony movement do exist to protect Varroa-free territories.

  • Links to climate

    Seasonal cycle linked to climate

    Infestation increases proportionally with the amount of brood rearing (brood is usually present from spring to autumn, in temperate climates), with a peak of infestation in summer, after the main honey harvest (time for treatment). Climatic conditions influence brood rearing (the population dynamics), with a stop in brood rearing when temperatures are too low or too high.

  • Distribution of disease or vector linked to climate

    Temperate climate is optimal for both the honey bees and Varroa mite reproduction.Parasite reproduction depends on the amount of brood rearing of honey bees. The latter are influenced by climatic conditions.

  • Outbreaks linked to extreme weather


  • Sensitivity of disease or vectors to the effects of global climate change (climate/environment/land use)

    Bees are affected by weather conditions, therefore the parasite is affected by climate through an indirect effect.Too high or too low temperatures reduce honey bee activity and the amount of brood, as a consequence also the Varroa load is reduced.

    More problems linked with Varroa reproduction are present in warmer (Southern Europe) climates because of the availability of bee brood throughout most of the entire year depending on the geographic area. Climate change might have a negative impact due to the reduction of brood-free periods of honey bee colonies in some European regions, as well as the reduction of blooming duration linked with too dry or too rainy seasons.The control of Varroa with some products can be more critical in Southern Europe due to high temperatures during summer. As an example, this is the case of the volatile compounds (e.g., formic acid, thymol, other essential oil, etc.). Always in Southern Europe, it can be more difficult to find a brood-free period during winter time. Climate changes could make the problem even more severe in the future.

    GAPS :

    In the tropics, varroosis is only a minor problem. The reasons for this balanced host-parasite-relationship are still unknown. Probably related to long-lasting cohabitation, easier possibility to find melliferous resources, higher tendency to swarming, and non-intensive beekeeping.

  • Main perceived obstacles for effective prevention and control

    Limited availability of medicines; poor treatment strategies; harmonisation; need to integrate beekeeping techniques with medicines treatment (IPM) :

    • Varroa still represents the number 1 problem for beekeepers worldwide. They have to properly manage this pest;
    • Beekeeper and Veterinarians knowledge on Varroa control to some extent;
    • Limited availability of effective, cheap and “easy to apply” control methods;
    • Common recommendations of veterinary/extension services, at least for some state, is often lacking or insufficient, or are not always followed by beekeepers;
    • The available diagnostic methods are not satisfactory.

    GAPS :

    Treatment application by beekeepers and veterinarians, beekeepers and veterinarians skills in the use of diagnostics and veterinary medicinal products.Apicultural organisations and Veterinary Services should be more involved in the continuous education and training system.Accessibility of the POM (Prescription Only Medicine): only the veterinarians must prescribe the medicament. Beekeeper groups can ask for a common prescription in some EU countries under the responsibility of a veterinarian. This should be applied in all EU countries when possible.Several risks: risk of Varroa-resistance; risk of lack of efficacy; risk of residues in beeswax and honey; risk of toxicity on honey bees (adult/queen, brood); risk of toxicity on the operator (e.g., sublimated oxalic acid; formic acid).However, there are medicines available on general sale in the UK and other member states (e.g., in Italy none of them requires veterinary prescription) without the need for a veterinary prescription.Consideration should be given to provide as mandatory POM for all honey bee treatments in all EU countries.National regulations on veterinary medicinal products are not harmonised, differences do exist among member states.

  • Main perceived facilitators for effective prevention and control

    The presence of Varroa in the colony is not always easily detected by beekeepers, unless severe infestations occur (when the recovery of the colony is difficult).

    GAPS :

    Clear recommendations are needed.Better training for veterinarians and apiarists to provide better information and knowledge on Varroa prevention and control, residues, and resistance risk.A better system should be developed to integrate beekeepers, associations, veterinarians, experts (e.g., data analysts for Varroa monitoring; weather experts to forecast for a better parasite management and for a better pharmacological control) working together = multi-actor strategy.

Global challenges

  • Antimicrobial resistance (AMR)

  • Mechanism of action

    Not applicable (V. destructor is a parasitic mite, antimicrobials are not needed/used).

Main critical gaps

    • New veterinary medicinal products are required for Varroa treatment and control and there is a need to encourage chemical testing for Varroa control.
    • Education of endusers of the veterinary medicines to optimise their efficacy, depending on the climatic context, the way of administration, the dosage and the biology of the bee colony.
    • There is a need for the development of quantitative sensitive tests for early and easy diagnosis of the disease and infection levels, along with tools to assess colony health in relation to immunity, virus loads and stress status.
    • Sustainable treatment approaches based on Integrated Pest Management
    • Knowledge on honey bee immunity and on the possible application of vaccines within the beehive.
    • What is the extent of resistance to acaricides and how can we detect it?
    • More research on possibilities and feasibility of biological control is urgently required to include control of mite reproduction, mating and host finding.
    • Development of selection criteria for the breeding of honeybees naturally tolerant/resistant to Varroa.


  • In almost 30 years there has been no new treatment against Varroa (last new development: oxalic acid, Radetzki et al., 1994). The only improvements were concentrated on formulation of active substances, mode of administration and to some extent integrated control strategies (biotechnical methods in association with veterinary medicinal products - IPM). All the recently authorised veterinary medicinal products frequently have the same active ingredient, i.e., oxalic acid, and mode of administration. The implementation of beekeeping techniques and biotechnical methods have much improved during the last 8-10 years, but this could much be improved by a proper control of the infestation.The disease situation is even worse in recent years, requiring several treatments along the year, but there have been no new developments since.

Sources of information

  • Expert group composition

    Franco Mutinelli, FAO RC Animal Health and Food Security Discipline Apiculture, health and biosecurity and NRL for honey bee health, Istituto Zooprofilattico Sperimentale delle Venezie, Italy –[Leader];

    Severine Matthijs, NRL for Bee Diseases, Sciensano, Belgium;

    Marc Schäfer, WOAH and NRL for American foulbrood, Small hive beetle infestation (Aethina tumida); WOAH RL for Varroosis (Infestation with Varroa spp.) and NRL for infestation with Tropilaelaps-mites, Friedrich-Loeffler-Institut, Germany;

    Giovanni Formato, FAO RC Animal Health and Food Security Discipline Apiculture, health and biosecurity; WOAH CC Good Beekeeping Management Practices and Biosecurity Measures in the Apiculture Sector, Istituto Zooprofilattico Sperimentale del Lazio e della Toscana, Italy.

  • Date of submission by expert group

    27 June 2023