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.