ABR Review 2022 – Spring 2023


While we continued our activities during the Corona years, all beekeepers, volunteers and Arista employees enjoyed the regained freedom to – literally – work closely together on the diverse sets of tasks in our breeding program. The good selection results are “contagious”, which is reflected in the number of beekeepers that would like to join the program. For this reason, we need to expand our fundraising efforts as those beekeepers are most effective and efficient when they can be supported by a project leader from Arista.

In this update, you will find an overview of the 2022 results. 2022 was the 9th year of Arista, 2023 will already be our 10th anniversary! A good moment not only to reflect on what has been achieved but also to start planning what our direction could be for the next decade.

Progress in the breeding program


In 2022 we welcomed Marian Meyer in Beers (the Netherlands) as a new Project Leader. He received his Bachelor of Horticultural Sciences in Berlin (Germany) where he already worked on VSH behavior. Marian has been a passionate beekeeper for 6 years and went through a steep learning curve last year to acquire the necessary skills in the VSH breeding program. He is now supporting the Dutch beekeepers in the NL-EU SIB funded VSH breeding program. He also monitors and supports the breeding done with our Arista (donor/sponsor) hives.

Spring inseminations

The good weather early in the season, all over Europe, allowed a quick start in breeding and production of vital queens and drones for the many insemination sessions. Throughout Europe, Arista supported about a dozen groups with the insemination of around 1000 queens. A thousand other queens were inseminated by beekeepers from the participating groups. Three years ago, Arista started with inseminations courses for the groups to ensure more and more queens can be inseminated by the beekeepers themselves.

Before the season started, we also prepared and shared a high-quality semen diluent, essential for instrumental insemination. A total of 6 liters was produced at the facilities of InHolland University of Applied Sciences in Amsterdam, providing us with a sterile environment to do so. The recipe has been used successfully by Dr. Guillaume Misslin for more than 20 years and allows the conservation of semen, under the right conditions, for at least 6 weeks.

Preparing high-quality semen diluent

Single Drone Insemination results

This year 130 breeders participated in the Single Drone part of the breeding program, divided into 31 groups in 7 countries. We assessed a total of 1065 test colonies. This was the first time we passed the bar of 1000 colonies, a great milestone for all participating beekeepers.

Again, the results were very good: 34% of these colonies (367 in total) are considered high VSH, meaning such colonies can fight the mite on their own and do not need any treatment against Varroa. Out of these 367 high VSH colonies, 43% (149 in total) are fully resistant which implies that they remove all reproducing Varroa mites. So, even after adding 100-150 mites to these colonies, not a single reproducing Varroa mite is found in the brood (after opening 300-600 cells…). These colonies are classified as 100% VSH.

Explaining and demonstrating insemination

Multi Drone Insemination and Land Mating Stations results


Every year selected high VSH SDI test colonies are sent to Italy. The local beekeepers produce daughters and let those mate in a dedicated mating station populated with high VSH drone colonies. The first year the colonies grow and are assessed on mite infestation. The colonies with less than 3% mite infestation are wintered without treatment and assessed the second year for all important traits like swarm tendency, gentleness, honey production and, of course, Varroa infestation.

Arista team, beekeepers and volunteers for collecting of semen in Italy

The best performing colonies, usually one or two per original SDI colony, are kept to produce drones the third year. So, in May 2022, 3 project leaders and 5 volunteers again went to Northern Italy to collect semen from the best performing Varroa resistant colonies.

This extremely valuable semen was then distributed back to the participating groups that originally supplied the SDI colonies. The collected semen allowed the insemination of 682 queens. The colonies developed from those queens will once again be assessed by the beekeepers for all the important traits, including Varroa infestation. This Italian selection step ensures that we not only select for VSH (in relatively small Single Drone colonies), but also select for all the important traits in large production colonies under standard field conditions. Of the queens which were inseminated in Belgium, and sampled later on during the season, 85% had very low mite levels and did not need any treatment.

Collecting semen in Italy


The transnational Belgian-Luxembourgish, Varroa resistant (land) mating station of Sélange hosted a total of 412 virgin queens during 5 periods of two-weeks each. The results of the matings varied from one period to another, e.g. the first period turned out to be least favorable for mating with better results in the consecutive periods. Overall mating success was a little below 60%.

All those queens will be assessed in production in 2023, like the Italy project. Those colonies with the best overall bee-qualities (honey-harvest, low swarming tendency, gentle) and very low mite counts will be used in 2024 as drone colonies. The first results of the queens which were mated in 2021, look very good in terms of production quality and Varroa resistance. More data have to be collected for proper quantification.

Year after year, more and more naturally mated queens are evaluated in Sélange. The queens tested are a mix of older (longer selection, higher VSH) and younger lines (with new bloodlines, for more biodiversity, but generally lower VSH). Of 251 colonies sampled in 2022, 62% were Varroa resistant (<3% infestation). As with the other land-mating stations, there is still a “dilution” of our high VSH drones with non-VSH drones from non-VSH colonies not controlled by Arista beekeepers.

Brood counting in Belgium

This is not a problem for the breeding program as we only use the drones from the best colonies in the case of land mating stations; with drone eggs being un-fertilized, they only represent the mother. When more and more VSH ends up in the non-Arista colonies close to the mating station, the higher the resistance level of the queens mated on the land mated station will become. It is of course the end goal of the participating beekeepers to not have to treat any of their colonies against Varroa.


In Luxembourg, located around 3 km as the bee flies from Sélange, is the (land) mating station of Fingig. This mating station is provided with drone colonies from the Luxembourg VSH breeding program. The mating station hosted 409 mating nucs which allowed 347 queens (85%) to be successfully mated. Here, the mite levels of the colonies from the VSH breeding program are also monitored through mite washes. More than half of these colonies show high levels of resistance against Varroa.


As in the previous year, we kept the land mating station at Bronlaak in operation to produce queens for production colonies. Mainly beekeepers from neighboring bee-associations participate, by first grafting larvae from high VSH colonies at Arista in Beers and then bringing the mating nucs to the mating station around 2 weeks later. Several of these beekeepers do queen breeding and preparation of mating nucs for the first time. From the queens mated in 2021 we have a large range in the measured mite infestation levels. Several queens score very nicely with scores below 3% and often even 0% but at least one third of the queens has also much higher mite counts (5-15% in September). For the breeding program the best queens can be used, but for the participating beekeepers it is not nice if a significant part of the queens is still not protected against the Varroa. During the last two years we have unfortunately identified several, previously unknown to us, beekeepers (with non-VSH bees) very close to the station

This made us decide to move the station to Linden, a small town very close to the Arista headquarters and partly surrounded by water. In cooperation with a local beekeeper and the bee-association Bernheze we will manage this mating station. In addition to the better geographical location, we will also increase the number of drone colonies on the station to further improve the VSH mating results.

Mating station Bronlaak


The Flevoland breeding group and mating station has decided to fully concentrate on the VSH breeding program, supported by Arista. So, 2022 was used to make several combinations (MDI inseminations), to test colonies (for mite infestations) and to produce the VSH drone colonies for their mating station. This implies that the mating station will change its role to become more of a tool in the overall VSH breeding program, from as it was used more for distribution of material in the past.

Education for the breeding programs

Both during the season and winter we educate beekeepers on certain topics for a successful breeding program, using various different channels. In Belgium we performed webinars concerning breeding and selection for different strains of bees (Black bee, Carnica and Buckfast) and on the Arista VSH breeding program.

Furthermore, we provided courses both on location and online on topics such as selection and preparation of drone colonies, selection and management of pedigree data in our in-house developed Queenbase software and insemination as well. The level of support we can give with our full-time project leaders in a country, depends on the amount of financial support (either private or governmental) available in that particular country.

Education in Belgium

Research & Development

Genetic marker for VSH

This project started in 2018 as a collaboration between Arista, Van Hall Larenstein, Inholland and Bejo Seeds under a “RAAK-pro” grant. Each year, Arista collects samples of bees from dozens of colonies, during the many VSH counting sessions. From all these samples 75 very high VSH and 75 very low VSH colonies were selected for further analysis, so those with the biggest differences in VSH levels. From each of these 150 colonies, the full genome was sequenced and mapped (each sample being 20 workers). The resulting genetic code from each of the colonies in the two pools were assessed, comparing the high VSH colonies with low VSH colonies, to find differences that would hopefully be responsible for the VSH behavior in the high VSH colonies (or the lack of it in the low VSH colonies).

We are very excited to report that we indeed found several significant differences between the genomes of the two groups. This is very good news! However, this is not yet proof that the genes or regions identified are responsible for the VSH behavior itself. They could be, but it could also just be areas on the genome that are more or less prevalent in high VSH or low VSH bees. In case of the latter, they could still be of use as a marker, but great caution should be taken, as the genome of the honeybee has a high rate of recombination. For that reason a certain sequence might only be related to high VSH for a limited amount of time or limited part of the population.

A lot of progress has been made, because we have not only identified these regions, but we also have a large database with the full genome of a large number of colonies. Now, with the identified areas and the full genome in place we can semi-automatically search for small pieces of genetic code that are unique for the identified regions on the genome. These small pieces of genetic code are the basis for creation of probes: markers that can be used in a (quick) laboratory test. Both the high-VSH-linked code and the low-VSH-linked-code can be used to produce small pieces of DNA that “glue” to either the high-VSH or low-VSH regions. By attaching a fluorescent compound to the small pieces of DNA, which has a different color for high and low VSH, a marker test is created.

We are currently developing candidate markers which we will first test on existing samples, with known VSH levels, to determine the predictive value of the markers. We will then select the most promising markers, to create a panel that we can use to test a much larger set of samples, to be collected in the months and years to come.

The genetic analysis and markers are currently performed and created based on mainly one strain of bees (Buckfast). If the markers work, we will have to show that this is the case for other strains of bees as well. Depending on how long ago the genetic trait has been established, more or less adaptations would have to be made to make the tests work on other strains of bees as well.

So, a very large step has been taken (identification of areas on the genome). Now the development of probes/markers has to show, whether this can indeed be translated into a successful test for the selection of resistant honeybees. Such a test would be of extremely high value, as we could both screen far more colonies for our breeding program (having to do only a relative simple laboratory test) and at the same time collect very detailed information of the level of resistance per queen including possible missing genes in case of partial resistance. In these cases, “matching” partners could be identified with the same test to increase the level of resistance in the next generation.

Arista, Inholland and Bejo Seeds will work together on these genetic markers, supported by the approved NL-EU-SIB-government grant. Together, we will also look for further funding and partners to develop this very promising tool on the widest possible basis (different strains of bees and geographically).

In summary, we have not find the holy grail yet but we did find pieces of the map leading to its discovery. We have become even more motivated to keep looking for it. We trust on Aristaeus to help us on this exciting journey, but can use any additional support in this treasure hunt…

VSH rapid test

We have started to work on a rapid test that could be used by a beekeeper to determine the level of resistance/VSH of a colony without doing the elaborate brood count or having to wait for a long time to see if the mite levels remains low. Basically, such a test kit could be another holy grail, if it would reliably predict the VSH level.

One of the approaches for such a test is the use of odors, compounds that could be linked to the VSH behavior. Application of such compounds to the brood would ideally trigger the brood removal behavior – specifically in VSH colonies and not in non-VSH colonies.

The UBO test is one of the first developed potential tests, developed by Kaira Wagener. UBO stands for Unhealthy Brood Odor. In 2022 Arista had its own project in Netherlands, but also supported a project in Belgium with Buckfast Flanders and University of Leuven as main contractors. A large number of colonies (>60) with different levels of VSH (as measured in our brood assay) were studied for their generic hygienic behavior using the two standard tests; the Freeze-killed brood test and the Pin-killed brood test, in addition to that the UBO test (a spray with selected compounds) and the standard VSH brood count were performed (infestation of brood with Varroa and count of remaining reproducing and non-reproducing mites). In line with a lot of research done in the last few decades, the Freeze-killed and Pin-killed brood tests showed measurable, but low correlations to both the VSH brood test as well as the UBO test. The UBO test itself showed only very low or no correlation to the VSH brood test.

For the hygienic tests it is known that the environmental circumstances (honey flow etc.) can impact the results of the tests. So, the UBO test could possibly give higher scores in spring than in summer (when we did the tests, as summer is also the period when we do our VSH brood tests). However, Arista is not interested in just hygienic behavior, which has shown to be only weakly correlated to Varroa resistance. We also do not believe we should rely on mechanisms that would only be prevalent in short periods of the year or under very specific circumstances. That is why Arista has decided to not continue the work with the UBO compounds.

Whilst we were working on these UBO compounds, a paper by Fanny Mondet on a different set of compounds was published: the “VPS” compounds (Varroa Parasitization Specific compounds). Fanny Mondet has been able to show these compounds are only present in the cell when young mites are present. This is very interesting as this is also the base of the VSH behavior: the removal of brood that has young mites present…. Supported by the Goeie Grutten grant and advice from Fanny Mondet we have now started to work on this approach. We hope we can do the first experiments this year to see whether these compounds could indeed be used for the development of a VSH rapid test.

Arista hives

The 22 Arista hives in the Netherlands are playing an increasingly important role in our activities. While the financial contribution is already 1/3 of our budget, the colonies are also a bridge to new beekeepers and local associations throughout the country. As these colonies are often taken care of by local beekeepers, they often become ambassadors of our program in their region.

In addition to the Arista hives in the Netherlands, we have been able to get the support for our first Arista hive in Belgium! The Arista hives also are a good source for our breeding program. This spring we brought several queens back to the Arista headquarters in Beers as they headed the best performing colonies. In addition to the very low mite levels, they performed well on honey harvest, low swarm tendency and gentleness.

Arista sponsor hive in Belgium for Accenture

Now back at Arista these queens are part of the “top-league” and used by the participating beekeepers in the breeding program. Thank you, Arista hive donors and sponsors!

Overall the Arista hives are doing very well on the mite levels. Combining the data of the last 2 years, on average the mite levels stay around or below 1 % from the start until the end of the season (obviously without any treatment). These very low mite levels also are reflected in how the colonies get through the winter. This spring we wintered out 41 high VSH inseminated queens in total; the Arista hives plus reserve queens on Mini-plus hives. Only one colony did not make it to spring! This is a very good result compared to the overall, national percentages of winter losses of colonies in the Netherlands and Belgium, which are in the range of 30 to 40% (with most beekeepers doing several treatments per year). And the differences are not just in the number of colonies surviving the winter but also in the strength of those colonies . We also see very low winter losses counted as frames of bees in most of the high VSH colonies. Basically winter-in = winter-out. For non-VSH colonies most beekeepers consider it “normal” if a colony reduces in strength by half between before and after the winter. We now experience the overwintering of colonies as it was before the Varroa started its destructive work in the 1980’s…

The next decade

At the end of this year, Arista will be active for 10 years. What did we learn and what are the plans?

There are several lessons we learned during this journey.

The first one is that “it works”. Running a breeding program, based on the inventions of the USDA combined with modern bee breeding selecting methods, results in fully Varroa resistant honeybees with good beekeeping traits. It is a lot of work, but the results are very good and make all the investments in blood, sweat and tears well worth it! Now we need to  set ourselves up for doing this for a broad selection of the honeybees (strains, bloodlines) and broad geographical representation.

The second lesson is the need for cooperation. Those beekeepers that have organized themselves in breeding groups were most successful. Being in a breeding group ensures that important pieces of information are available and shared. Lessons are learned collectively, successes are celebrated together. Whereas beekeepers are sometimes known for working alone, basically the common enemy has brought us together. The model where a group of passionate beekeepers is supported by Arista project leaders for support and coordination, is working very well.

Arista team, beekeepers and broodcounting crew, Elzas, France

The third lesson is that funding those Arista project leaders works best if national bee-associations become actively engaged in supporting the acquisition of national, EU and private subsidies. The region of Wallonia has been the most successful so far. But bee-associations in the Netherlands have also actively supported the first NL-EU subsidy for Arista.

More progress could and should be made in other countries, like the large bee-country Germany. This spring in Germany a very encouraging initiative was started during a large conference (https://varroaresistenzprojekt.eu), organized by all the major bee-associations.

Representatives of neighboring countries were also invited, as well as the bee-institutes. The conference is currently being followed up by regular workshop sessions to prepare written proposals that can be submitted to the German authorities and to form a plan to breed a Varroa resistant honeybee in a large cooperative setting. During the conference the ambitious target was set to convert the German honeybees towards Varroa resistance by 2033! Arista takes part in the working groups and is very motivated to support this ambition.

Looking more to the west we have to conclude that, despite the fact that the VSH was discovered in the USA (USDA, Baton Rouge), only a few initiatives have been started with limited implementation so far. Given the experiences of the last 10 years in Europe, as well as the progress we are making towards a genetic marker, Arista has reached out to the USDA to re-start a technical transfer of the breeding techniques to the US bee-industry. It is our objective to start a combined set of initiatives, using the expertise of both the USDA and Arista. This program will address the development of tools as well as the creation of a pilot project producing fully Varroa resistant production queens.

And then looking more eastwards we have recently been approached by parties in New Zealand and Australia to see what can be done to start a Varroa resistance breeding program. It would be very rewarding if the knowledge built up so far could also be applied on this side of the planet!

So, the next decade basically can be described as “geo-expansion”. While developing new tools like the genetic marker, we are now ready to involve more bee-associations, beekeepers and bee-dependent companies in a more global setting.

Thank you

The big steps forward in the VSH breeding have only been possible by the hundreds of volunteers who, are active in the program. A very large, diverse set of tasks is being executed by a large number of volunteers.

Arista teamwork: volunteers work on filling and labeling honey jars and painting of hives

Firstly, the beekeepers that participate and produce quality queens and drones for the SDI and MDI sessions, spending their precious time throughout the year on this demanding task alongside their other beekeeping, professional and private activities. One test colony requires the equivalent of more than a full working day. Weeks of free-time are invested each year, to produce a new generation of potential breeder queens. Secondly, the selection would not have been possible without the support of the numerous volunteers, beekeepers and non-beekeepers that asses the colonies by carefully examining the infested frames, but also support the program in 1000 other ways like preparing the counting room, catering for the counting and insemination days, the overall logistics, preparing frames and hives, extracting honey, doing mite-washes, processing data etc. …

A big thank you also goes to the various governments that support us, and to our sponsors, private donors and funders that enable us to support the beekeepers with the professional support of our project leaders. In addition, these funds make it possible to do the research to develop new tools for the selection program.

Thank you all for your contributions that make it possible to keep us passionately pushing for healthy bees in more and more regions and countries.

The Arista team

Spring 2022 – Review 2021


As in the first Corona year, also in 2021, the participating beekeepers have been able to actively work in the program with spectacularly good results. We now see that the enormous amount of work done since 2014 proves that the assumptions we started with – that there is a little bit of Varroa Sensitive Hygiene (VSH) in the honeybee population and that that can be selected for by Single Drone Insemination (based on the work from the USDA going back to 1997) – are working out in practice.  

In this introduction we first give you a “refresher” on the method we are using, followed by the latest results.

The method is based on 4 types of mating of the queens; Single Drone Insemination, Multi Drone Insemination, Land mating stations and Island mating stations. Each of these types of mating has its own advantages (and disadvantages), but are powerful if used for the right purpose. That is why the overall program is a mix of these 4 types.

  1. Single Drone Insemination (SDI):
Artificial insemination at Beers, NL.

This is the first and important step of the selection of Varroa Sensitive Hygiene (VSH). We produce large numbers of small colonies with different genetic backgrounds. Each colony is headed by a queen inseminated with a single drone.

After adding extra Varroa mites, we investigate the brood and determine the level of resistance (Varroa Sensitive Hygiene, VSH). This allows us to basically find those queens/colonies that were mated with a highly resistant drone. Only colonies with queens that remove 75% or more of the mites are kept. The daughters of these queens will carry the resistance genes, creating the basis of the breeding program.

Please note that at the beginning of this selection process we estimated that only 10% of the drones would carry enough VSH genes.

In the case you use more than one drone at this stage, like in normal mating with approximately 10 drones, the effect of one drone carrying enough VSH genes is diluted by the 9 other drones carrying no or little VSH gens. When VSH genes are diluted, there is not enough resistance left to detect/measure it.

2. Multi Drone Insemination (MDI):

Multi Drone Insemination (MDI) at Beers, NL

The SDI colonies are very well suited starting from a population with limited VSH genes. SDI colonies can only be small and are relatively short lived (because of the limited amount of sperm stored by the queen). As they are small, the colonies cannot be easily selected for the other important traits as honey production and low tendency to swarm. For this reason, we inseminate a larger number of queens with the semen of at least 10 drones. As we are now later in the selection process, most of the drones will carry the resistant genes. These colonies can be kept much longer (2 to 4 years) and can be tested for the described traits. We also monitor the varroa population growth in these colonies by taking samples (300 bees per colony) to determine the number of mites on these bees (instead of in the brood), called the “phoretic” mite count. This is a method that can be used at large number of colonies without too much labor involved.

The advantage of using Multi Drone Inseminations is that we can keep the biodiversity as high as possible. We can use a large variety of different drone lines compared to a mating station that usually has only one or two different lines per year.

3. Land Mating station:

The disadvantage of the MDI colonies is that it requires special insemination skills. The amount of work involved makes it less suitable to do large scale production of mated queens in the broader beekeeper community. Therefor we are more and more making use of land mating stations. On such a mating station, ideally somewhat isolated from other apiaries, we place colonies that will deliver drones carrying varroa resistance genes. As this is a land mating station, we assume that a certain, hopefully low, percentage of the drones comes from colonies from other beekeepers. This means that the mated queens will not produce 100% “pure” colonies. However, the queens mated on these stations can be used in production colonies in which they will be assessed for our selection program.

So from these land mated station queens/colonies we do not produce further queen offspring (they could have low resistant genes from the not-pure drones), but we can definitely use the (pure!) drones for our selection program.

Indeed, the best colonies can then deliver well selected drones, because drones are coming from unfertilized eggs. They just represent the genes of their mother, they have no direct biological father!

We have experienced in our Hawaii program and now also in our EU program that using this step is actually very powerful. Given the relatively large number of colonies that can be produced and monitored (only a few samples of bee washing are needed for phoretic mite level assessments per year), a both strong and still broad selection can be made based on high resistance as well as good honey collectors, gentleness and with low swarming tendency.

4. Isolated mating station:

Whereas the previous methods are very helpful during the selection process, they are not very useful for diffusing the breeding progress to the beekeepers that do not participate in the selection program. Those beekeepers are interested in purely mated queens (“F0”) that  can be used to graft from in order to produce their own F1 queens for their production colonies. For this distribution of good traits, using an isolated mating station (an island or a remote mountain valley) can be a very efficient way. We will see that more and more isolated mating stations are using Arista or (at least partially) Arista derived queens as the basis for their drone lines. This will facilitate the distribution of the resistant genes in the different honeybee  populations – and will eventually even benefit beekeepers that are not visiting mating stations at all as their queens will be more often mated with varroa resistant drones from their neighbors.

It is important to note that we are not yet in a position to supply all these mating stations with new, non-related and highly resistant queens, year after year. We should also ensure that we do not lose the more than 100 years of selection (either by beekeepers or by nature) by moving too fast with the still limited number of Arista validated lines. We are now at the turning  point; we need the full support of the beekeeping community but also from the governments to extend the program and to ensure that we keep the genetic base of the honeybee as broad as possible. The method works, it is “just” a matter of implementing it 😊…

Progress in the breeding program


Dr. Guillaume Misslin, our Project Leader located in the Netherlands and Sacha d’Hoop, our Project Leader located in Belgium, support around 200 beekeepers distributed in 18 groups within: Belgium, Germany, France, Luxembourg, the Netherlands, Austria and Switzerland. In the 18 groups all three main races of bees are represented: Black, Carnica and Buckfast bees.

SDI-Varroa counting sessions at Paul Jungels, LUX.

In Belgium we could welcome a new Project Leader: Julien Duwez. Freshly graduated in bioengineering from Gembloux, he was already involved in the project as a participant before starting to work with us. His arrival in the team will allow us to improve the coordination and the follow-up of the participating Wallonia beekeepers as well as to improve the training of those that recently joined us.

Explanation of the method at Sélange, BE.

The beekeepers in the program are supported by the Project Leaders in the choices to be made in the use of lines, in the queen and drone breeding techniques and in the varroa infestation and counting sessions. Furthermore, the Project Leaders also organize insemination courses with the groups, so they gain more autonomy and flexibility.

The total number of colonies that has to be followed and monitored is increasing as we now maintain more and more colonies mated in the different described ways. For this we fortunately have our in-house, tailormade web-based database application “Queenbase”. It is more than ever the tool to be used; to report back to the Project Leaders the production and phoretic data of the colonies gathered during each season as well as the pedigrees and offspring data for the queens in these colonies.

Single Drone Insemination results

The number of colonies we could test for removal behavior (Varroa Sensitive Hygiene; VSH) in SDI colonies was 969, an increase of 56 compared to the previous year. As in previous years, about 1/3 of the colonies removed more than 75% of the reproductive mites (the minimum required to not need chemical treatment). These high VSH colonies can be used in the breeding program.

Varroa family in a brood cell

More than 100 of the high-VSH colonies removed all – 100% – of the reproductive mites from the worker brood. We have now demonstrated this year after year, but it is still a small wonder to see that the bees remove the Varroa mites so well themselves and that this trait is transferred into the next generation. To evaluate the colonies, volunteers open the brood cells to investigate its content. The total amount of opened brood cells is still increasing compared to previous years as at higher VSH levels we find less mites, so we open more cells to still get enough information. Furthermore, we do more and more recounts, just to be sure that the high scores are indeed sustainable if measured multiple times.

The fact that 2/3 of the hives are not high VSH is because we ask the beekeepers to keep bringing in new blood (good, new lines, but not VSH). Therefore, the program is a mix of new lines that are in the first years of selection (initially low VSH) and already proven lines (high VSH).

Land mating stations and Multi Drone Insemination results


As we described in the “Land mating” paragraph, and as we learned in our Hawaii program, you can make a very good contribution in the selection by using production colonies.

Collecting drones in Italy.

As also described in previous updates, we have been able to build a “well-oiled machine” with a group of highly skilled professional beekeepers in Italy. Every spring, and thus also in 2021, we delivered a set of SDI colonies to this group. From these, more than 300 queens are bred and mated with drones from colonies also coming from our program (selection from the previous year). These 300+ queens are heading production colonies that have to prove themselves in production and are followed and evaluated for several years on the phoretic mite infestation (simple sample of bees “washed”), gentleness, honey yield and low inclination to swarm. From the best colonies (after 1, 2 or 3 years) large amounts of semen are collected by capable inseminators/beekeepers during a second visit in the spring. This semen is transported in proper conditions and used for multiple-drone inseminations of breeder queens at the beekeepers from the different participating countries.

2021 is a special year for this selection. After all the years of preparation and pre-selection, this was the year that queens, inseminated in 2020, had to prove themselves (for more than) a full year. For this purpose, in 2021, 16 queens in the Netherlands were followed by taking samples. Throughout the full year these colonies, of course without any treatment, kept the mite infestation around half a percent! Control colonies (non-VSH) would have grown the mite levels to around 10% in the same timeframe.  We are very happy and proud of these excellent results – made possible by 8 years of work with a good cooperating group of now 200 beekeepers.

It is furthermore striking that already in spring these colonies seem much larger and healthier than “before” (in the early 1980’s, the Varroa mite entered our countries). And also in the fall the colonies are large and look more healthy compared to what we are used to.

Maybe this should not be a surprise? The bees are doing something that beekeepers cannot do that is removing Varroa mites 24 hours a day, 7 days a week. As a result, the pathogenic virus infections (distributed by the mites) never have a chance. This is the main difference with the current practice of chemical treatment. You can treat as good as you can as a beekeeper (e.g. 3 times a year), but the virus infections only decrease slowly after a Varroa treatment (takes weeks/months). In fact, you don’t directly treat against the viruses that are causing the main problem for the colonies. And after a chemical treatment against the Varroa, it just starts growing again, until the next treatment. The still present viruses can then just “hitchhike” again. And last but not least, there is no impact of chemical treatments on the bees. Now that we can actually start beekeeping with really healthy colonies again, we realize more and more to what we have become “accustomed” to in the past 40 years… it is truly a relief to be able to practice beekeeping with “normal”, healthy colonies again!


The method used with our Italian colleagues, is also implemented in Belgium and the Netherlands.

In Belgium we established the first transnational resistant mating station in Sélange (type “land mating station”). It is the result of a partnership with l’Abeille Arlonaise, a beekeeping section from the south of Belgium. Not only is the aim to allow high resistance matings, but also to create an area without varroa treatment on the long term. In 2021, the mating station was opened to members, generating around 360 queens from many different resistant lines, that can be used to produce males for future inseminated queens. It is asked not to treat any of the colonies that originate from those queens, unless a phoretic count proves it is necessary (which obviously eliminates these queens from the program).

Text Box: Arista land mating station at Sélange, BE.
Arista land mating station at Sélange, BE.


Arista land mating station at Bronlaak, NL.

Also in the Netherlands we opened our own land mating station, close to our offices. This station is run by local beekeepers and coordinated by Arista. We have admitted 14 beekeepers for the time being. These beekeepers receive the starting material (larvae) for queen breeding from us and then have these virgin queens mated in small fertilization boxes. Just like in Italy, the fertilized queens can then be used in production colonies for the further selection of good drone material in the coming years.

Island mating stations

The VSH lines that become available have also drawn the interest of several island mating stations. They are reserving part of their capacity for putting lines on their mating station that have certain levels of VSH incorporated.  

Ameland (the Netherlands) has had several different VSH lines at the station in 2021 on a separate part of their island. This enabled Arista beekeepers to send their mating colonies and select for different lines.

Also in Germany there are more and more mating stations that can now include Varroa resistance as a selection criterion by using queens that have an origin in the Arista breeding program.

In 2021 a first start was made on a cooperation program with the Flevoland group/station. This group will from now on be solely dedicated with the selection and distribution of Varroa resistant queens. Already in 2023 the mating station will be “manned” with queens coming out of the Arista breeding program.

As earlier stated, we are too early in the program to fully switch to varroa resistant queens on all the mating stations. For that we need a more diverse and broader selection of resistant lines – respecting the large amount of work and quality available in the not-yet varroa resistant lines.


Genetic marker for VSH

In the Genetic marker project we are trying to find the genes – or a genetic marker for these genes – that are linked to the VSH behavior (collaboration Arista, Van Hall Larenstein, Inholland, Bejo Zaden). We are very close to a first, very important analysis as full genome of the target colonies has been sequenced. If all goes well the first analysis on the full set of data will be available this summer (2022). Hopefully we will have a first indication whether we will indeed have a powerful tool to speed up the selection… to be continued!

VSH rapid test

It is important that we find ways to make the very labor-intensive selection more efficient and/or effective which is a reason for the described genetic marker research. The selection process could be more efficient if we would have a way to select for the VSH trait without having to breed, infest and count the Varroa mites themselves…

We are therefore pleased that the Goeie Grutten Foundation has granted us a subsidy (starting in 2022) to develop a VSH rapid test. Such a test would not require Varroa mites and would have to give a relatively quick idea of the level of Varroa resistance/VSH. For this, we will look at specific odorants that might be used in place of the mite. For this part of the research we work together with the University of Greensboro (US), the Buckfast Flanders group and the University of Leuven.

We will also investigate other ways to mimic the effects of the Varroa, without using the Varroa mites themselves.

Arista hives

Arista sponsor hive

At the end of 2021, we had a total of 21 installed Arista sponsor hives. These hives have queens from our selection program and are used to further evaluate and use the best lines. Both in 2021 and 2022 we already distributed drone brood and larvae from the best of these colonies to mating stations and participating Arista beekeepers.

A nice “side-effect” is that those (regional) beekeepers that take care of the hives often are new to our program. Their first-hand experience and their own network make our program known to a wider group of beekeepers.

Furthermore, we have spent a lot of time, with also highly skilled “pensionados”, on the proper functioning of the monitor system (weight/temperature/beecount in-out). The current version is very stable, works in all places where we have hives and is fully integrated with the software (Queenbase) of our breeding program.

The financial contribution from these hives is critical to the survival of our breeding operation. We hope we can further expand this program and welcome more donors/sponsors for an Arista hive!

Thank you

We thank our donors and sponsors for their financial contributions that enable us the organizing of this complex pan-European program.

We thank all the participating beekeepers and volunteers for the incredible amount of time, passion and expertise they invest in the Varroa Resistance breeding program on a daily basis.

Spring 2021 – Review 2020

Location & Covid

In the Netherlands, we moved from the family house in Katwijk to the ex-cow-AI-station in Beers in March 2020 (see our previous update). At this location we have a lot more space at our disposal and this actually saved us during the outbreak of the Covid pandemic.

In March and April, an instant decision had to be made: what to do with the breeding program? Not only the activities in Beers, but also the groups in all other countries (including Italy, close to an area with a major outbreak) were facing the question “what to do next”. 

Since a one-year pause would have been disastrous – after all, you have to breed a new generation every year – it was quickly decided to try and give it all to continue. That turned out very well. Even with social distancing, special logistics for inseminations and counting, and electronic meetings, we managed to achieve a “record” year. 

At the Beers site, we stayed open – with extra measures – and even welcomed extra volunteers.  We were able to do this without any transmission of Covid at work.

Progress of the breeding program

In 2020, the number of participating beekeepers in the various countries grew to 133.

This is also reflected in the number of tested colonies. In 2020, 912 colonies were tested for mite-removal behavior (Varroa Sensitive Hygiene; VSH) – a record number in the Covid affected year of 2020!

One third of these colonies (312) were found to be high VSH, removing 75% or more of the (previously added) mites from the brood. Colonies with 75% or higher VSH are able to survive without any chemical treatment. Of the 912 colonies, 79 colonies removed all mites from the worker brood, so these colonies are 100% VSH.

The best colonies are used for further breeding, also taking into account other characteristics, such as gentleness and honey yield.

As mentioned in our previous update, we have established a partnership with experienced (professional) beekeepers in Italy, whom we again provided with new queens to breed from this spring. The daughters of these queens are mated with drones from our program in a mating station. These queens are used for production colonies and the best ones are selected, based on mite infestation, honey yield and gentleness, among other things.

This spring, we were once again able to collect semen from the best colonies in Italy (daughters of queens we had brought in 2019 and 2020), for the inseminations of more than 500 queens in Belgium and the Netherlands. These queens received the normal amount of semen (from about 10 drones) and will be introduced and tested in large colonies. The first results look good (low mite infestations, high VSH in tested colonies), however, we want to follow the colonies a bit longer before we draw our conclusions.

In several countries, beekeepers have been trained by Arista to perform inseminations themselves.

Our project leader Dr. Guillaume Misslin made his 5000 km trip to the various participating beekeeping groups in Germany, France, Austria and Switzerland. During this trip he gave insemination courses to 17 eager beekeepers and inseminated 990 queens for the program. Teaching more beekeepers to inseminate enables the breeding program to grow further.

Mating stations

Apart from the “Italy route”, there are also more and more mating stations with colonies from our breeding program. On the island of Ameland, there are, as we speak, many colonies from beekeepers in our program. Starting from VSH queens, several lines of drones have been prepared by the Ameland group. Furthermore, there are land-mating stations in Germany and Austria, our own land-mating station in Belgium is now well used and at this time, the first queens are being mated at our land-mating station in Bronlaak, near Beers. At the same time, there are also mating nucs at a new station of the Amstelland group.

At all these mating stations normal “multi-drone” matings are performed, which enables the use and testing of these queens in large colonies. Clearly, we are entering a new phase in our program. We will continue the single drone inseminations (small colonies) to find new lines with high VSH, but will be making more and more large colonies, to be able to select on the other traits (honey yield, gentleness, swarm-weariness etc.) as well.


The collaboration of Arista Bee Research, Bejo Zaden and the Universities of Applied Sciences Inholland and Van Hall Larenstein has succeeded in sequencing the complete genome of 48 high and low VSH colonies. Furthermore, the VSH behavior was recorded extensively on video. We are now working hard on the analysis of this first important data set. Meanwhile, 100 additional colonies have been selected to have their genome analyzed. We hope to have the data from all the colonies at our disposal at the end of 2021. It will be very thrilling to see whether we can find the needle (a piece of DNA code that correlates with the VSH behavior) in the haystack (the entire bee genome) …

Arista hives

In 2020, we started delivering the first Arista Adoption Hives in the Netherlands. This specially developed hive (with solar panels, computer and sensors) contains a queen from our breeding program. Such a colony actively participates in the selection and spreads the genes for the Varroa resistance behavior to other colonies in the surroundings through the drones.

The sponsor can follow the progress of the hive via an app, which shows e.g., the weight and the number of bees flying in and out of the hive.

Despite the Covid pandemic, we have been able to place 13 hives. Governmental (municipality of Cuijk, municipality of Mill and Sint Hubert and the province of North Brabant) and business organizations (several Rabobank locations, ZLTO, Triple, Torn) as well as charitable foundations (Adessium, Elise Mathilde) have adopted a hive.

The Arista Adoption Hive concept is rolled out with the support of local beekeepers and beekeeping associations. The Varroa resistant material of the colonies in this program is also shared with these beekeepers. Therefore, the program is both a selection program and supports the distribution of Varroa resistant colonies in the beekeeping community.

The program has already been very successful this year. From the best colonies, queens have been made available to mating stations in Ameland, Flevoland and North Brabant.

Thank you

We thank all the participating beekeepers and volunteers for the incredible amount of time, passion and expertise they invest in the Varroa Resistance breeding program on a daily basis. We thank our donors and sponsors for their financial contributions that enable organizing of this complex pan-European program.

Spring 2020 – Review 2019


In April 2018, already two years ago, we were able to move into our own location in Katwijk, Noord-Brabant. The upper floor of the house was for our project leader Guillaume Misslin, the living room, kitchen, an extra room and the garden were at the disposal of the rest of the employees and volunteers. However, the number of volunteers grew so quickly that last March we moved to a larger location: the ex-AI-station at the Dr Moonsweg 5 in Beers. The new owner has made a business collection building there, of which we now rent a part.

Where previously cows were artificially inseminated, it is now the turn for queen bees… So it remains a AI-station 😉. At this new location we have 2 large offices at our disposal, a kitchen, an archive, a laboratory and a spacious storage. And of course, a large outdoor area for our bees. It is great to have enough space for all the projects of our staff, volunteers and students!


The method for the selection of Varroa-resistant bees is adapted little by little each year depending on progressive insight but has remained largely unchanged.

At the start of the selection in a new group or breed, the emphasis is on using the “single drone insemination” principle (SDI). We make small colonies and do not use the normal sperm mixture of 8-10 drones but sperm from only 1 drone per queen.

This is a very important step. By using only 1 drone, all workers have the same mother and father. This makes it much easier to select, as you can see all the characteristics come to the fore to a greater extent. As soon as the hive is on its own bees, extra mites are added and 2 weeks later, the degree of infection in the brood and the ratio of non-reproducing versus reproducing mites is examined. Next, we only use colonies with a low level of mite infestation and a high percentage of non-reproducing mites. In these colonies, most of the mites that reproduce have been removed by bees – a sign that the workers (and therefore also the queen) carry the Varroa Sensitive Hygiene (VSH) trait. It is these colonies that are used to continue breeding.

Where at the start of the selection mainly these 1-drone colonies are used, in the next phase more normal (large) colonies are used with queens inseminated with 8-10 drones. With these large colonies (the second group) it is easier to select for other important characteristics such as honey production, gentleness and disinclination to swarm. In these colonies the growth of mites is monitored by determining the infection on the adult bees. The best colonies are used as a basis for the queens of the next generation.

The third important group of colonies in the selection program are the open-mated (production) colonies. In these colonies the infection on the adult bees is also determined after a season of “production” (and obviously no anti Varroa treatments). The best colonies, both in terms of mites and honey production, can then provide the drones to the first and second group already mentioned for the next generation of colonies.

Breeding program in the USA

Hawaii, as we know, is not only a beautiful holiday destination but also a “Varroa paradise”. The mite can propagate here all year round in the beehive and beekeepers have to treat against Varroa 4 times a year.

However, with the application of the system with the three groups of colonies, as described above, beautiful results have been achieved since 2015.

We have now reached a very high level of resistance in our inseminated breeding queens. This means that this group has not been treated for two years now. In these colonies the mite infestation on the bees remains on average below 1% throughout the season.

These good results enable us to continue with a simplified breeding program. This program will be further supported by the USDA in Baton Rouge.

However, as in Europe, a greater effort is now needed not only to secure the existing lines but also to make several other lines/sources/breeds resistant. We have therefore set up an American sister organization of Arista in Dallas, Texas, to support the selection and breeding of Varroa resistant bees on the mainland of the US beekeepers.

Breeding program in Europe: Buckfast, Carnica and Black bee

In the Netherlands, Belgium, Luxembourg, Germany, Austria, Switzerland, France, Spain and Italy a growing number of Buckfast, Carnica and Black bee colonies have been infected with mites in recent years and assessed for their degree of resistance. Mainly mini-plusses (small boxes) were used, of which the queen was inseminated with sperm from one drone. In the first year, 2014, there were almost 100 colonies and in the past year more than 800, made by 119 beekeepers.

262 of these colonies were “high VSH”. High VSH means that 75% or more of the reproducing/fertile mites are removed from the worker brood. One third of these “high VSH” colonies was as high as 100% VSH. This means that in these colonies, even after adding extra mites, no mites with offspring can be found in the worker brood. This is something to think about for a moment…: So it is actually possible to grow bees that take all the reproducing mites out of the worker brood.

Now that we have reached this level with small 1-drone colonies we will make more and more of our colonies with the usual 8-10 drones (MDI: Multi Drone Insemination) in the coming years. Artificial insemination will continue to be the best method to keep as much diversity in the population as possible. You can make sure that you use as many different sources as possible on the maternal as well as on the paternal side.

As described in the paragraph Method, there is a third group that is very important for further breeding – these are the open-mated colonies that can serve as drone suppliers. This year we started to work with major honey beekeepers in Italy to put our lines into practice and test them for honey production and mite growth. Last year they were able to breed queens from 16 Buckfast lines (from NL, BE, LUX) and have them mated in a VSH land mating station. These queens have been introduced into normal honey colonies. From the best colonies, if all goes well with the Corona, we will collect sperm next month in Italy to make the next generation of breeding queens in the Netherlands, Belgium and Luxembourg.

For the distribution of pure material to large groups of beekeepers, the mating station on the islands work best. Arrangements have now been made for this with the mating station on Ameland. Ameland has recently received highly resistant queens from us (bred in Belgium) and will turn them into drones (i.e. breeding daughters to produce drones) that can then be used by participants of the Arista program next year. These beekeepers will then be able to have their queens mated on the island.

But we are not there yet. We will have to “convert” an even larger part of our Buckfast, Carnica and Black bee stock. In fact, we delivered a nice “proof of concept”, showing that the setup works in principle. With the proven method, we can now pick up and execute the selection with many more beekeepers. This requires more project leaders in the Netherlands as well as in the other European countries and the US. In order to allow larger groups of beekeepers to participate, we are implementing a full training and education program: “Arista Academy”.

In order to make these investments in training and project leaders, we need financial support. To achieve this, we have now started our new sponsorship program: the “Arista Cloud” – aimed at companies, government agencies and municipalities. In this program the sponsors will get a special hive with a resistant queen and a monitoring system. We hope that as many parties as possible will want to adopt an Arista Cloud hive from us!

Genetic Marker project

In the genetic marker project excitement is growing. We have succeeded in collecting bee samples from a large number of both very low and very high VSH colonies.

The Inholland University of Applied Sciences has already isolated the DNA of half of the samples and we are now in the queue for the determination of the whole genome (outsourced to a specialized lab). After this, Bejo Seeds and Inholland can use modern software to search for the differences between low and high VSH colonies! Searching for pieces of DNA that can be predictive for whether or not VSH is present…

With Van Hall Larenstein we also managed to make a large number of infrared video recordings of infected frames in low, medium and high VSH colonies. For the first time, we are able to “watch” what is really happening in the colonies on a large scale. Van Hall Larenstein is currently working on the first analyses of this large mountain of visual data. To be continued!

Publication of scientific overview article

Jacques van Alphen and BartJan Fernhout have written an overview article on the development of Varroa resistance in honeybees: “Natural selection, selective breeding, and the evolution of resistance of honeybees (Apis mellifera) against Varroa”. This article was published in June in Zoological Letters!

The article can be requested via the following link: https://doi.org/10.1186/s40851-020-00158-4. In this article we discuss the natural development of Varroa resistance in certain regions (like Africa) and the need for breeding programs in Europe and America.

Thank you

The growth of the past years has only been possible through the contributions and efforts of the donors and many beekeepers in the various countries. We would like to thank everyone for all their support and continue to focus on our ultimate goal: Varroa-resistant bees for all beekeepers worldwide!

Spring 2019, overview 2018.

US breeding program

In Hawaii we had a quite turbulent year. At the start of the year we were very happy to present the breeding program to the Brandpunt-TV crew which made the effort to join us to Hawaii and Baton Rouge and made a nice overview of activities and progress.

As can be seen in the documentary (link on our website), their visit coincided with a large increase of activity of the Kilauea Volcano. Large flows of magma erupted from a large area, destroying more than 700 homes. David Thomas, the beekeeper that houses our program, had to remove a large amount of honey production colonies out of the active area. The colonies in our breeding program were fortunately not affected and during the summer, the magma flows came to a stop.

Originally, a normal colony on Hawaii had to be treated against Varroa around 4 times per year – as there is no winter, the mites can multiply in the brood all year round. Half of the colonies in the program are now treatment free, while the other half is down to, on average, a little bit more than 1 treatment per year. The average amount of mites per 100 bees has been steadily decreasing, to below 2% on average. This is very nice as this is below the to-be-treated-against-Varroa level of 3%.

2018 was a bad year from the weather point of view (yes, even on Hawaii): there was a record level of rain which hampered a normal honey flow. Fortunately, 2019 looks to become a more normal year, which will enable us to do more selection on the amount of honey a colony collects – also an important trait for a commercial honey bee.

EU breeding program: Buckfast, Carnica and Black Bee

More than one hundred beekeepers are now actively running the selection program in Austria, Belgium, Germany, Italy, France, Luxemburg, The Netherlands, Spain and Switzerland. Almost 700 colonies were prepared, infested with mites and assessed on their resistance level. 189 colonies were identified as highly resistant (≥50% of reproducing mites removed from the brood). Of these, a third of the colonies removed all of the mites and are considered 100% resistant.

To enable the distribution of the resistant stock to a larger number of beekeepers and also to produce production colonies of the participating beekeepers in our program, isolated mating stations have started to use highly resistant queens of our selection program as a basis for the production of their drone producing colonies (usually 20-40 colonies per station).

Beekeepers can bring their virgins to these stations where they are naturally mated with the highly resistant drones.

Especially the Bayern Buckfast group is already very active with the supply of queens to three stations: Karwendel, Leyhörn and Ammergebirge in Germany.

There is also a station running in Luxembourg, which was joined by a  newly complemented station in Belgium (Sélange-Arlon), just on the other side of the border.

After the Hawaii trip, the Brandpunt TV-crew were eager to make a second documentary of our activities in the Netherlands (see also the website). In this documentary Gerbert Kos and members of the Marken mating station are explaining what is entailed in the project and how the mating station of Marken works.

In this documentary the importance of the pollination tasks of honey bees was also explained by our partner Bejo Zaden in Warmenhuizen.

2018 was the first year for the Black Bee group in Belgium joining our program. A total of 34 colonies were counted for VSH and already 8 colonies were found to be highly resistant – a very nice score for a first year!

The large growth in participating beekeepers has been made possible by the recruitment of two new project leaders.

Guillaume Misslin, both a very experienced bee breeder and a trained molecular biologist, joined Arista in April (made possible by financial contributions from the Adessium and the Dioraphte foundations). As he already participated in our program he was quickly up to speed and is now supporting the groups in the German speaking areas (Germany, Switzerland, Austria) and the Carnica groups in the Netherlands and Luxembourg. Guillaume was also active in the Barbados project.

The second project leader we were able to recruit in 2018 is Sacha d’Hoop de Synghem. Sacha is a graduated Bioengineer and beekeeper. His recruitment is made possible by financial contributions of the Walloon Government to the newly created entity Arista Bee Research Belgium.  Sacha quickly took up the massive amount of organizational and training tasks which resulted in an even higher number of participating beekeepers in Belgium (>60).

Terschelling project

On the island of Terschelling a Black Bee project was started with the cooperation of all beekeepers on the island. Many of the colonies on Terschelling seem to be quite “black”, judging by their colour.

However, Buckfast bees and Carnica bees have also been held on the island for quite some time. So, we started a small project to see whether there are still enough relatively pure colonies to start a Varroa resistant Black Bee breeding program.

For this, Merel Rookmaker and Bart Lubbers, students of the Van Hall Larenstein University of Applied Sciences sampled all the colonies on the island and used the “fingerprint” of the wings of the worker bees to determine how “black” the bees are. From the 150 sampled colonies, 30 colonies were considered black enough (with 65-92% of the workers fully black and the remaining workers close to this) to keep. The queens of the other (less black) colonies will be replaced with daughters of these black queens during the coming year. This selection process will be repeated to further increase the purity. At the same time, we will start monitoring the mite-growth in the colonies to get an idea on the current level of resistance. This will enable us to prepare ourselves for the Varroa-resistance-selection-part of the project.

Genetic Marker project

2018 was the first year of the “RAAK” project, the consortium with Inholland University of Applied Sciences, Van Hall Larenstein University of Applied Sciences, the company Bejo Zaden BV and Arista Bee Research. The different partners each have their own expertise and tasks in the project.

Arista Bee Research is responsible for the creation and identification of colonies that have very low and very high levels of VSH. From each of these colonies, 50 bees are collected and stored for analysis. We were able to collect samples from more than 50 colonies with either very low or very high VSH.

This is enough to start the next phase of the project: the extraction and sequencing of DNA which Inholland and Bejo Zaden have now started to work on. Once sequencing has been done, we can start comparing the low and high VSH colonies looking for differences between the DNA sequences.

Van Hall Larenstein started the phenotyping of the behaviour which means that we will confirm that it is indeed VSH behaviour (removal of the infested pupae/mites from the brood) in the highly resistant colonies, by investigating captured video of bees on Varroa infested frames of brood. 

Barbados project

We were able to conclude all the needed measurements on 10 untreated colonies in Barbados. The results over the year are quite stable: relatively low mite levels on the bees as well in the brood, clearly showing high levels of resistance. The USDA is now investigating the bee-samples we took for virus levels and possible Africanization.

We will be compiling the data in a publication which will give a more detailed overview in the results and conclusions. The project has been made possible by financially contributions from the Bayer Bee Care centre.

Arista Academy

During the last few years we compiled a lot of knowledge and “do’s and don’ts” relating to our selection program. At the same time there are a lot of beekeepers that would like to start participating in our program or that would like to further develop their skills.

So, with the help of a new volunteer, Marjolein Bemelmans, we have started to build a comprehensive training program; “Arista Academy”. We will work hard to make the program available for participating beekeepers in the spring of 2020.

Arista Cloud

As we now have shown that the Arista selection method is working, it is time to further expand the breeding program.

In line with the increasing number of beekeepers, the number of project leaders, technicians and staff members will also have to grow. This also implies further investments in the establishment and furnishing of a European center with offices, lab, apiaries and training space as well as investments in equipment such as insemination sets, microscopes, incubators and freezers.

So, we are currently very busy for the launch of a new sponsorship program, tailored towards companies, governmental institutions and communities: the “Arista Cloud”.

By adopting one or more Arista hives with a Varroa resistant queen, one would become both a participant and a sponsor of the Varroa resistant breeding program.

Such a hive would be fully maintained by Arista & partners and will be monitored for (lack of) Varroa infestation, honey collection etc. Both Arista and the sponsor can follow the hive on an internet-dashboard to see how the hive is doing. The colonies in the hives contribute in two different ways to the program: Firstly, the drones from these colonies will distribute the Varroa resistance by mating with queens in the neighborhood of the hive (up to 10 km from the hive). Secondly, Arista will select the best queens and re-use them in the breeding program to produce the next generation.

We will further update you with more details on this Arista Cloud program once we have completed our logistic preparations. We are working hard to breed queens, prepare special designed computer monitored hives, etc. . Interested parties can already contact us for more information.

Brandpunt+ Hawaii

Please watch the documentary of Brandpunt+ (KRO-NCRV) of our Varroa Resistant breeding project on Hawaii (English subtitles).

This breeding project has been made possible by a cooperation of the USDA in Baton Rouge, Hawaii Island Honey Company, Project Apis m. and Arista Bee Research.

To help us to continue our projects, you can support us by making a donation.
Thank you very much for your interest & support!


Growth and good progress in 2017

Boxmeer, May 17th, 2018.

Full resistance in the US Breeding program
In the US we have been working very hard to establish a breeding centre for Varroa resistant bees, in close cooperation with Bob Danka from the USDA in Baton Rouge (supplying pre-selected semen from the USDA bee-stock and financially supporting the program), Danielle Downey from the non-profit organization Project Apis m. (financial support and administration) and David Thomas from the Hawaii Island Honey Company (infrastructure, personnel and financial support).

A dedicated laboratory was built on the Big Island of Hawaii. On Hawaii we have a long season, enabling us to produce and select multiple generations per year.

With the financial support we have been able to recruit and train 4 employees, so since last year we are able to run the program “full throttle”. We have 200 small colonies for housing our inseminated queens and 600 large hives to house our breeders and drone supplying colonies. All these colonies are tracked with our in-house developed “Queenbase” software application.

In addition, David Thomas is running all his honey production colonies in Hawaii (several thousand) with queens from the breeding program. The progress made in the program is very encouraging and also gives us a lot of information which we use in the EU breeding program (and vice versa).

With commercial queens, colonies on Hawaii required treatment up to 4 times a year (brood in the colonies year round, so a “Varroa-paradise”), in contrast, the bees from our program are currently treated less than 1 time per year on average. The best lines reach full resistance and keep the mite infestation levels very low during a full year – without any treatment.

We are now working on establishing these high levels of resistance in a broader selection of our lines. Furthermore, we also have to ensure that the lines perform well from a honey harvest and pollination point of view and that they perform well in the commercial operations on the mainland of the United States (so field-trials are being performed).

The very good results on Hawaii show us that fully Varroa resistant bees are feasible and encourage us all to keep working hard – both in the US and in the EU.

Strong growth in our EU-breeding program
We started our first year – 2014 – with 6 breeders in our breeding program. The number of breeders has grown since then from 16 in 2015, to 35 in 2016 and up to 66 in 2017! In Europe, we currently have participating groups in Austria, Belgium, Germany, Italy, France, Luxemburg, The Netherlands, Spain and Switzerland.

With the growing number of breeders and breeding groups, the number of colonies being tested in the program increased to 390 in 2016 and grew further to 646 in 2017. 134 of these colonies showed high resistance against Varroa (> 75% of the reproducing mites are removed from the brood). Colonies with this level of resistance do not need treatments against Varroa. Twelve colonies did not have any reproducing mites at all in their brood (after receiving 100 to 200 mites two weeks earlier and then checking 300-400 brood cells) and are considered fully Varroa resistant (100% VSH). As these are in most cases one-time measurements, we will perform additional measurements on these colonies and use them in 2018, to confirm their level of resistance. The queens of these highly resistant colonies are usually inseminated with just a single drone. These single drone inseminated queens allow us to make quick progress in our breeding program, but they can only be housed in small hives and have a limited life expectancy, because of the limited amount of semen they received. We are now in a position where we can also start to produce more multi (8-12) drone inseminated queens, using the material from our resistant single drone colonies. These multi drone inseminated queens can be housed in regular sized hives and we will start evaluating these queens on other important traits, like honey production and winter-survival.

We will continue to look for extra financial resources so we can further increase the number of beekeepers and colonies in the program in order to obtain the needed high diversity in the resistant pool of colonies.

Carnica, Buckfast and now also Black Bees
We started our program with Buckfast and Carnica beekeepers. These two races represent a large proportion of the honeybees in Europe and so the majority of our current program consists of different lines from these races.

However, there are local native sub-species in Europe that are considered important, given their unique set of traits and genetic background. One of these races is the Black Bee (Apis mellifera mellifera) which is one of the ten recognized European bee sub-species. With the popularity of the Buckfast and Carnica, and the extinction of feral, natural wild colonies due to Varroa, several of the Black Bee populations are considered endangered and could also benefit from a Varroa resistant breeding program. So in 2018 Arista will start working with the Belgian Black Bee group Mellifica.be in creating a first set of single drone inseminated queens, which will be tested and selected for using our established method.

Furthermore, the beekeepers on the island of Terschelling (the Netherlands) have joined up with Arista to create a Black Bee breeding program on the island, making the island a reserve for Black Bees. This breeding program will also include the selection of Varroa resistant lines, using our selection method. In 2018 we will find out how pure, how “black” the bees are on the island. Based on the findings, we will make a plan to establish a pure, Varroa resistant, Black Bee population.

Genetic Marker projects
As we now get a first base of fully resistant colonies, it becomes possible to start projects based on these bees. The standard method which we use to select for Varroa resistant colonies is quite labour intensive. It would be a big help if we could test and screen our bees with a simple (genetic) test – if only such a test would exist…

To develop such a test, it is necessary that we improve our understanding of the underlying genetics of the Varroa resistant behaviours, like Varroa Sensitive Hygiene (VSH: the detection and removal of the mites from the brood). For this reason Arista formed a consortium with the Inholland University of Applied Sciences (Amsterdam) and Van Hall Larenstein University of Applied Sciences (Leeuwarden, Velp) and the company Bejo Zaden BV. Last summer, together, we managed to get a “RAAK-pro” project proposal approved and we have now started to work towards finding a genetic marker for the resistant behaviour. Arista will supply the bees for the project and will support Van Hall Larenstein with analysing the behaviour (“phenotyping”) of the bees. Inholland and Bejo Zaden will look for the genetic background of the behaviour (“genotyping”) by comparing bees that do and do not perform the specific behaviour. This project is supported by a committee composed of members of the NBV (Dutch Beekeepers Organization), BBV (Buckfast Beekeepers Organization), VCI (Carnica Beekeepers organization), the Laboratory of Genetics from the Wageningen University and the BVNI (Professional Beekeepers organization).

Arista has also started to support the BeeStrong project of the INRA institute in Avignon, France. 40 Arista colonies were counted last summer for VSH and bee samples were taken for genetic analysis at INRA.

Barbados project
There are a few places in the world where it is believed that honeybees have become resistant against Varroa, without the help from humans. Barbados may be one of these places. When Varroa established itself on the island in 2002/2003, the bee population crashed and most of colonies collapsed. Most of the colonies on Barbados are “feral”, so unmanaged colonies, living in the rainforest. A small number of beekeepers catch swarms of these feral colonies to populate their hives. Most of these managed colonies also collapsed, because beekeepers did not treat against Varroa.

Interestingly, after several years the beekeepers again started to get phone calls, asking them to come remove swarms. Now, around 15 years after the first outbreak of Varroa, the population is considered to be fully recovered and beekeepers catch swarms and collect honey from their colonies, just like before the Varroa reached the island.

With the financial support of Bayer, Arista is now establishing a small project on the island. This project has the aim of establishing and following an apiary with colonies for one season and regularly determine mite levels on the bees and in the brood to establish the level of Varroa resistance. Furthermore, we will try to get a first indication which trait (possibly VSH?) the bees are using to keep Varroa at bay. In addition we will check the haplotypes of the bees, to exclude the possibility that the bees now present on Barbados are immigrated Africanized bees.

At the last visit, 10 colonies (untreated) were investigated on mite levels. The colonies showed very low mite infestation levels in the brood and most of the colonies also had low levels of Varroa infestation on the bees. So first data indicate indeed high levels of resistance. Will be continued…

Personnel & organization
In addition to the financial support that was established for the genetic marker, Barbados and US-Hawaii projects, both the Adessium foundation and the Dioraphte foundation have started to financially support our breeding program! These are important contributions as we can now build a small organization that can support the quickly growing group of beekeepers in our program.

The combined funding enabled us to have BartJan Fernhout move from the Board to the position of program director and to recruit Guillaume Misslin as a project leader. In addition, the Van Hall Larenstein (VHL) University of Applied Sciences is recruiting a project technician for the RAAK-pro project, which will be working with VHL students at the Arista location.

Furthermore, the Wallonia government in Belgium has approved the funding of a project leader for Arista! To achieve this, we founded a legal entity “Arista Bee Research Belgium”. This enabled us to recruit Sacha d’Hoop de Synghem who will be dedicated to work in the Wallonia area while working closely together with the Arista team in the Netherlands.

And last but not least we have been able to rent part of a house with a large garden, giving us space for an office-lab and an apiary.

We are very excited that we can now really start pushing towards our goal: Varroa resistant bees that thrive and keep themselves healthy, without relying on chemical treatments. For this we will further work on expanding the donor base, the professional support and the number of participating beekeepers and beekeeping organizations. The ultimate goal is that all beekeepers in the US and the EU can stop all chemical treatments against Varroa, while strongly improving the health of their colonies and strongly reducing the number of colony losses. This would ensure an uninterrupted supply of honeybees supporting the agricultural industry with pollination services and honey production. It would also support the recovery of the native local European subspecies of honeybees and the re-establishment of natural populations.

Further expansion in 2016

Arberg, November 2016.

New Buckfast group in Bavaria (Germany) got off to a flying start.

In Bavaria (South of Germany) an already very active Buckfast-Beekeeper and Breeder group (having grown from 100 to 500 members during the last 5 years – buckfast-bayern.de) has joined the other Arista VSH Buckfast and Carnica groups in the search for Varroa resistant lines.

Josef Koller, the chairman of this group, has been working on breeding Varroa resistant bees for 20 years. In recent years he has been supported by a growing number of interested people (one of them being Ralf Höling). Through his concept, he succeeded in selecting colonies that survived untreated for years. However, so far it had not been possible to make offspring inherit this trait consistently.

So, inspired by the stories from the already established Arista members, it was decided to start a Single Drone Insemination VSH project. Many emails were sent during the winter and so the group started very well prepared in the spring of 2016. More than 40 test colonies were created, using mainly two Buckfast lines that had proven to have the lowest mite counts during the previous years.

The  large experience in the group with Varroa counting (determining infestation levels), combined with the Arista experience paid off as large amounts of mites were harvested, with newly constructed buckets and many kilograms of powdered sugar, to infest the 40 test colonies.

Early August the group (combination of beekeepers, family, friends and Arista volunteers) came together for three days and established the level of VSH for each colony by counting the reproducing and non-reproducing Varroa’s in the brood.

It became clear early on that all the years with few or no treatments whatsoever (with the consequential colony losses) paid off, as in their first year, half of the tested colonies already expressed high levels of VSH. With these good results in mind, the group immediately took action and organized another insemination session in the fall to produce offspring from the colonies that were found to have the highest VSH level. 93 colonies were created and these colonies will be available in the coming years to produce drones for new Buckfast combinations.

After this very good start, the group in Bavaria with coordinator Stefan Luff, as well as the neighboring Buckfast-Süd group, are preparing themselves during this winter for the coming year, to expand the number of colonies and lines in the program.

Good results continued in 2015

Boxmeer, June, 2016.

Existing Buckfast group (Belgium/Luxemburg/France/Netherlands/Germany/Austria)

The group, established in 2014, continued in 2015 with both the pure Buckfast lines as well as the Buckfast-USDA crossed lines. More than 160 colonies were created and tested over the course of the year. In Altea, Spain, our breeding station became fully operational.

New breeders joined the team and a new group of extra volunteers was recruited to count the growing number of colonies – spending a week of their holidays to help us out!

Whereas in 2014 we had 10% of our pure Buckfast colonies in the high-VSH segment, the 2015 score was 23 of the 94 colonies (more than 20%) in this segment of 75% VSH and higher, showing a successful selection. Also in the Buckfast-USDA based lines the high VSH could be confirmed with 40% of the colonies in the high VSH segment (27 of 68 colonies).
1 Altea - Counting

New Buckfast VSH groups in the Netherlands

We are very happy to welcome two highly experienced, existing Buckfast breeding groups; the Buckfast breeding group Marken and the Buckfast breeding group Flevo. These Dutch groups have established mating stations in Marken and the Flevopolder.

Both groups started in 2015 to screen their breeding stock for regular hygienic behaviour, as there are indications that colonies with high levels of regular hygienic behaviour are more likely to also show the VSH trait.

From the best scoring colonies, 24 single drone colonies were established and counted. Two colonies were identified with high VSH (=>75%), 4 colonies had intermediate levels of VSH.

As the two groups started with completely new Buckfast lines, this is an important achievement as it will broaden our (genetic) base of high-VSH Buckfast.
2 Marken - Flevo-counting

New Carnica VSH group in the Netherlands

A very important and broadly used bee race is the Carnica bee. While already cooperating with the Kirchhain Institute in Germany (which uses Carnica), we were also able to establish a group of experienced Carnica breeders in the Netherlands, to join the Arista Bee Research program. The group created and tested 59 colonies in their first year of using the Single Drone VSH method. The very good news is that we were also able to clearly demonstrate VSH behaviour in the Carnica bee. We were able to find 13 colonies with intermediate VSH levels and 4 colonies had high levels of VSH (≥75%).
3 SDI-camo-minis -  Queen marked

Inholland University of Applied Sciences

The Inholland University of Applied Sciences (located in Amsterdam) has joined ABR and will strengthen the existing collaboration between the Genetics department in Wageningen University, the United States Department of Agriculture (USDA) and Arista Bee Research. While we have our third student working on VSH in the department of Genetics in Wageningen, now also students of the Inholland University of Applied Sciences have joined our program. These students will help us test the large number of bee samples being collected from the test colonies in the search for a VSH-marker (a test that could determine the VSH level by doing a lab-test instead of the labour intensive counting we currently do).
4 InHolland

VSH third generation breeding in US supported by Arista Bee Research

While our first visits to the USDA in Baton Rouge were used to learn the VSH methodology from our US colleagues, it also became clear that they are very much interested in the breeding experience that exists in Europe. For that reason, the USDA and a commercial beekeeper from Hawaii have requested Arista Bee Research to support the creation of a third generation VSH bee for use in the US. A collaboration agreement with the USDA and donations from the commercial beekeeper make it possible to do quarterly visits and give ongoing remote support.
5 Hawaii a