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!