All of you who have read my diary, http://www.buckfast.fi/publications/writings-presentations/, which has by the way been neglected by me for a long time now, know that a decade ago, 15.5.2009, I wrote:
“On average, counted from all hives, the bees do not manage an infestation rate above 5%. This result is a conclusion of the winter losses in 2007-2008 and 2008-2009.”
Counting mites is something that everybody doing varroa resistance breeding must do. More or less, sooner or later. But the tricky part is to avoid unnecessary work and false results. Counting mites every week is something I would call “too much”. Just lots of unnecessary work, because once a month should be enough. What about “false results”, what do I mean by that? For instance: if a beekeeper who is treating mites is counting mites once a year, he is very likely getting false results. Treatments have varying efficiencies and therefore mite counts, done once a year, are not telling which hive manage the mites best. Two mite counts a year is more than 100% better.
Some beekeepers are doing IPM based breeding and treating only those hives which have more mites than a set threshold. They do a lot of mite counting, usually only to get false results, because the threshold is set too low. The true mite fighters are never found. And the treated hives with their new queens get a head start and if you are not very, very carefull, you end up picking wrong breeders. That said, I agree that carefully done IPM breeding is possible if the threshold is set high enough and if the beekeeper has enough hives, so that each year treated hives can be compared as a group. Not with all hives, but with hives having the same treatment history. To be able to do this the beekeeper needs to have hundreds of hives.
What would be feasible, cost effective mite counting? I would say three mite counts during the main brood rearing season, one month or 6 weeks between the counts. This way the mite population increase can be counted. But even with this system there are flaws. Usually the swarming season and/or queen changes occur in this period. Every time there comes a new queen in the hive, arises the question: “How should the measured failure or success be counted in favor of the new queen versus the old queen? This consideration must be done if the queen change occurs in the period of those three counts. This problem is of course worse in short summer conditions like we have in Finland. It is important not to make the first counting too soon after the main brood rearing has started. During that time there is variation according to brood rearing start, some hives start earlier and heavier than others.
We had record warm days this week. There has never, in the history of temperature measuring, been +9,4 C in February in our Juupajoki measuring point. Although it was quite windy, most of the hives came out for their cleansing flight, or at least partial cleansing flight. Usually our cleansing flights are late March or in the first half of April. Three dead hives.
I took samples of dead bees from the queen excluders, which have served as mouse guards. I counted mites from 100 bees. The three dead hives had 10, 16 and 21% infestations, average 15,6%, The living ones had infestations between 2 and 8%, average 4,5% and median value 5%. I would suspect that the dead bees have higher infestation than the bees living in the hive, but of course I cannot be sure of that. Some of the hives with the higher infestations looked OK, one is very weak.
It seems that the limit of 5% has remained pretty much unchanged, although the percentage I was writing 2009 was from live bees. I´m somewhat surprised that is has not got any lower during these 10 years. It might be the result of my reservations towards mite counting. Would the right conclusion be that my mite counting has had no effect? One could argue that 10 years with at least some meaningful mite counting the average should be lower. But would my bees be now softer against mites? Or is 5% natural limit in our climate? Lots of questions and no answers.
This blog was supposed to be for more natural and treatment free beekeeping only. Today I must make an exception.
Yesterday evening I sat into my couch and turned on my TV, Skavlan was on. To those who do not know what it is: Skavlan is a Norwegian-Swedish television talk show hosted by Norwegian journalist Fredrik Skavlan. Skavlan is one of Europe’s largest and longest running talk shows, offering interviews with some of the world’s most well known personalities. (Wikipedia)
Fredrik Skavlan interviewed a young Swedish girl, whom I already had heard of.
Greta Thunberg in Skavlan talk show: https://areena.yle.fi/1-4463245
Some time ago in our national evening news there was a story of youngsters striking in front of our parliament house. They refused to go to school. When the interviewer asked them why they are striking, they answered that this is a support action to Greta Thunbergs original idea.
Today Greta is demonstrating in front of the Swedish house of parliament every Friday.
The same has now happened all over the world
Greta is going to take part in Davos World Economic Forum, and travelling there by train, and later this year she has a meeting with the Pope.
I was amazed. Some say we cannot do anything; the climate change and environmental disaster is inevitable. Greta Thunberg initiative shows that small things matter, they grow larger.
I decided to give up flying.
Jürgen Kueppers was one of the organizers of the first Conference for Treatment Free Beekeeping in Europe April 2018. After the talks Jürgen said to me that he is planning a visit to John Kefuss, who was one of the speakers in Vienna. Of course, I wanted to come with him. Toulouse would be south enough to have some resting holiday same time, I reconed.
After a French breakfast in our castle looking hotel Chateau du Comte in the 6th of October morning we hit the motorway.
With hard eye on the navigator screen we managed to find John at his honey house which is in the town area of Toulouse. It was 10 am and John suggested we sit down for tea and biscuits. The large building was a workshop of his father in law, who was an electrician. John transformed it to a beekeeping facility in the early 1970s.
What amazed me most was the amount and size of his woodwork machinery. John has always made his own equipment. They look very American style, finger joint, no isolation 10 frame Langstroth with “Kefuss” burned on the other short side. Boxes are dipped to hot paraffin, no paintwork.
Wax melting equipment in the backyard and foundation machinery inside makes him pretty much self-sufficient in beekeeping. Some sugar for feeding and diesel for his ancient looking open bed Toyota Landcruiser, that is about what he needs to keep it running, or Cyril does. Cyril Kefuss is his son and has taken over major part of the beekeeping operation.
Honey extracting equipment look something like 70 years old and 10 years since in use the last time. “Cyric has his own extractor” John said.
Tea pot whistled, and we took our drinks to table. The honey house ceiling has some transparent tiles which give nice atmosphere in the industrial and somewhat historical looking space. Noises from street and next-door school football field mixed into out talks, which lasted for two hours and we just scratched Johns carrier as a scientist and beekeeper! Ohio, USDA, Oberursel, Chile, Tunisia, luckily, I had read about his carrier before, so I could keep up with it all.
We even heard news which I cannot write here, very interesting unpublished data from a Ben Conlon study. It is about mites, of course.
One thing I did not remember reading was the reason he decided to stop treatments. In the mid-1990s there was an aerosol called Tactic (amitraz) used for varroa treatment. “In the next morning I felt like someone hit my forehead with a hammer” More to that, in a beekeepers meeting there were others having the same symptoms.
John Kefuss is the true pioneer of treatment free beekeeping. Cooperation with a German researcher Wolfgang Ritter was probably one major milestone. Ritter preselected Intermissa black bee in Tunisia, where the beekeepers had faced varroa but had no money to treat. In 1993 they took Intermissa bees to Toulouse and started maybe the longest lasting TF experiment ever made. It was published in American Bee Journal in 2004.
In 1998 he stopped all treatments and was prepared for 90% losses. He only got 60%. After that it is all history written by many others. Together with Ritter they launched Bond and Soft Bond beekeeping systems.
Today the situation has changed. John said he tries to keep about 50 hives. They are all treatment free, but his son has used Apivar for the last two years. The losses were too much for him. Cyril had to buy a lot of non-selected nucs after many of his hives were killed by pesticides. At the same time other beekeepers who treated also had similar pesticide problems. To be on the safe side he treats. “We have separate bees, this way everybody is happy”. John produces 150 virgin queens to Cyrils beekeeping every year, and the grafts are taken grafts from his best hives or Johns owns. With father and son having separate hives, and Cyril not being as keen note keeper as his father, it is sometimes hard to locate where one particular queen is. Luckily, they are attached with numbers.
The future is open. Cyril has not promised to continue his treatment free apiary.
After talks we walked couple blocks for a lunch in a local restaurant. For me, as an Aki Kaurismäki (Finnish world-famous movie director who loves France) fan, the place was quite an experience. Plus, the French food culture, it is something special. We had a marvellous lunch, Johns treat.
Then we drove to their country house, an old farm about 1-hour drive to north from Toulouse. On the way we stopped to look at couple beeyards with Cyrils hives. There I got to see Asian Hornets for the first time in my life. It has lately become one major problem for beekeepers in southern France. Jürgen had told me a lot about it but to see an Asian Hornet grasp almost every bee leaving for a flight, terrible!
John made a note about the hive in the picture above: surely interesting for future breeding because they have narrowed the whole entrance with propolis.
Approaching the destination road got smaller and smaller and after the last 700m I realised why he has his Toyota. Couple old oak trees from Henrik the 4th times stand nearby the main building. I had of course forgotten to take any gear with me, but John had hats and veils. The thick guest book was filled with names. John asked which hive we wanted to open and then we did. Hives were fairly week, but nobody got stings. We looked for how the brood areas looked and tried to find mites. We managed to find some and I personally one, which I of course got payed for! John Kefuss is famous for always paying one cent for every mite guest finds in his hives. A fantastic marketing idea for treatment free beekeeping, and tells me, that although he is a cosmopolitan today, John Kefuss was born American.
Picture of opened brood above and John paying Juhani below by Gabriele Steinig
The farm had a special building and facilities for grafting and insemination. Again, we were able to have a slightly longer perspective into beekeeping, there was the original MacKenzie instrumental insemination equipment among many others!
After the ride back to the honey house it was time to say goodbye. On our way to hotel a terrible thunder storm hit and couple weeks later several people were killed in mountain village floods near Carcassone. Luckily, we were back home by then.
Treatment free beekeeping is peanuts compared to climate change as a challenge.
During the years I have received numerous feedbacks from our customers. Some of them are good some more critical.
This blog update is done solely because of a feedback I specially asked for from Luca Consigli, our partner in queen rearing:
Copy from E-mail 3.10.2018:
”Running probably the biggest company into live bees’ production, my goal is to search always for breeders with best quality, honey production, low swarming tendency and no brood diseases breeders. To reproduce and sell to our customers. I met Juhani reading his varroa resistance story. I was curious to test varroa resistance tendency on big quantities and check also their commercial skills (I had bad experience with other varroa resistance queens in the past. No commercial characteristics so little honey production, aggressive temperament, sensitive to diseases or very little brood all season long).
Lundén’s breeders were left quite 2 years without treatments with other Buckfast breeders. They were the last to show collapsing signs. So, my conclusion was: best varroa tolerance (not varroa resistance in my Italian area just because hives density is very strong, and they suffer continuously varroa re-infestation from other colonies) and average commercial characteristics.
My real surprise was after 1-year test of f1 generation (Lundén daughter crossed with our Buckfast drones):
Best honey production, biggest and compact broods, no foulbroods, chalk, viruses but still low swarming. Good temperament and overwintering.
Yes, for sure they lose some of their varroa tolerance but still able to work from January to July with no varroa warning sign on bees and inside brood.
Probably it’s a very good cross because their isolation in Finland crossed with high standard stabilized European Buckfast score an optimum and positive hybrid vigour.
So, we decide to have an exclusive partnership also with Mr Lundén, to test his material on big numbers and to improve our Buckfast genetic bank with Varroa resistance new stock.
Very lucky decision by the moment.”
LUCA CONSIGLI, APICOLTURA LA FENICE (TRANSLATION FROM A SPEECH IN A MEETING IN BASQUE COUNTRY, SPAIN, FRANCE)
In mid-June 2015 I got a phone call from Kuortane about 80 km north from here. It was Reijo Avara calling and he told that near him is living a beekeeper who has been treatment free since 2001. His name is Heimo Kangasaho. Reijo said that Heimo had been with great enthusiasm reading my writings about treatment free beekeeping in “Mehiläinen” beekeeping magazine. I don´t know was Heimo too shy to make this first call or what but this was the beginning of our friendship.
My first reaction was firm denial. “Cannot be true!” I said to Reijo. But Reijo was persistent. He told me Heimos story, this is how it goes.
Heimo had been a beekeeper long time ago, but life forced him to give up with bees for a while. In 2001 he decided to start again, and he bought one beehive from Alajärvi, about 40 km north from Kuortane. This hive was the last living hive of a 90-year-old man who had to give up with bees. Heimo and I are pretty sure this old man probably did not even know mites existed.
I knew very little about mites 1996 when I suddenly got hit by them. Those late 1990 -years mites were almost everywhere in Finland, and I remember feeling a bit ashamed, almost like a fool, because of my ignorance. After all I have a university degree in beekeeping. It was a shock. By 2001 mites were all over southern Finland. Only Lapland and Åland were places where varroa had not come or spread, mostly by beekeepers themselves.
The more I listened to Reijos` talk the more I realized Heimos` story could be a very interesting one: In 2001 an old beekeeper is selling his last hive form a region which was surely hit by varroa years before, but by that time education and knowledge of treatments had not reached older beekeeper generations.
This last hive could well be a lucky survivor.
Heimo got home with his one hive and years went by, bee yard got bigger. Heimo has never cared about mites. After all he was a beekeeper before mites came. Sometimes Heimo went to beekeepers’ meetings, mites were of course major issue many times. When he told fellow beekeepers that he had not treated against mites they warned him firmly. “You must treat, or you lose them all!” they said. But Heimo is like me: just one hell of a stubborn beekeeper who does not like to be told what to do.
Many, many years Reijo Avara did not treat either. But in the end, he got so many warnings about his hives dying for sure, that he gave up and started to treat, even though he had had hardy any troubles with mites. You might say he was brain washed, but his reaction is very human. We listen advise and try to be wise and learn.
The story goes on
We first met when Reijo and Heimo drove to our home yard in June 27th 2015.
They had one black queen in a mating hive with them. “This is for you” Heimo said “but I don´t know if she has been mated” The weather had been rainy.
We went to see my bees and then looked some queen rearing gear Heimo has designed and build himself. I made my first visit to him couple months later.
In 2016 I went to see Heimo again and gave him one laying queen. Heimo told me later that after she had started to lay eggs in her nuc the bees changed her immediately. This daughter queen´s hive (F1) brought the biggest honey crop in Heimos` yard this year (2018): five Langstroth boxes full of honey, somewhere near 150 kg.
We want to forget about year 2017, it was so rainy that there was hardly any honey crop in this part of Finland.
The queen I got 2015 form Heimo had mated in his yard. So, it was a pure Kangasaho queen. I raised some daughters from her. I have already reported about the results before but put together the results are promising and there surely is varroa resistance in this queen. Variation in her daughters has been great, and it seem Heimos` bees are surviving in somewhat different way that mine. They build larger brood areas, but that is what F1 daughters do, one must consider heterosis which may have an effect too.
Luca Consigli (Puglia, Italia) reports also fantastic results with F1 daughters of our queens.
Pure Lundén Resistant Queens make smaller than average brood area, but of course not treating must have an effect. Mite infestation levels were aroud 2% this summer.
Visit to Heimo Kangasaho 21.9.2018
We neither have issues with angry bees. That is probably why I forgot my bee suit home. Never the less we inspected at least 10 hives and transferred honey combs from hives with more stores to lighter ones. We checked some queens too and saw some beautiful brood areas.
Just in the end of our operations I got one sting near my right eye.
We saw some mites, behind the hive entrance reducers and some even on the bees. Heimo loves gardening and has for instance pear trees.
Heimo is feeding quite late. I have already finished with winter feeding, but he had not even started. Situation was similar in my last visit in September 2017, after the record breaking rainy and cold summer, his hives looked weak and had almost no food at all. But somehow, after Heimo feeded them about 10 litres sugar, they managed to overwinter. No bees left outside died in winter, some died in spring and some small nucs brought in cellar to overwinter, died too.
Bees looked very well. His bees are mixture in colours, although he has been selecting in favour of black colouring. This hive has mostly black bees, can you find the queen?
The autumn has been warm, and his bees have been collecting nectar from clovers nearby. They all had plenty of stores. I was relieved. We put some feeders on, sugar syrup was waiting on his car trailer.
I brought Heimo bear fence gear, had one extra at home. He knows there has been a bear moving nearby, last summer it turned his trash over, made some marks on a tree and this year other villagers have reported seeing bear on the opposite bank of the Kuortane river. This bear in Kuortane has not learned to attack beehives yet, but hopefully he will assemble the gear. His bees are so valuable, that it is better to be safe than sorry.
Beekeepers in Kuortane and in many other similar places in Ostro Bothnia sort of live on islands: fruitful river bank fields where bees find plenty of honey and pollen surrounded by large meagre forests and swamps.
Beautiful red clover field in full bloom in Kuortane that day.
The surrounding areas are very often so rugged that bees cannot produce big enough honey crop for any beekeeper to be interested. There are no wild bees this north in Finland, swarms usually die in their first winter.
Heimo has many types of boxes: insulated wooden boxes and Styrofoam boxes from various manufactures. Most of his boxes are uninsulated and wooden, just like mine, mostly Langstroth frames but also shallower equipment.
So far Heimo and his bees have been living happily together with mites. Hopefully his beekeeping neighbors realize the importance of his work too.
There has been breeding and research to develop varroa resistant bees for a long time, over 30 years now. That is good, although nobody has come up with perfect varroa resistance.
Since now there has been very little talk about the transition period after varroa resistant bees have been developed. Only few people have openly come up with ideas how are we, TF beekeepers, going to be the majority. No matter however long that might take.
One of the first ones was Josef Koller. He developed the idea of ROOTs breeding -system. I wrote about it in one of my very first writings in this blog.
In ROOTs breeding system the basic idea is to start with one bee yard and keep it TF whatever comes. The place of the first bee yard should be as remote from other beekeepers as possible. Josef realized that it will be struggling but he reasoned that in the end the bee yard need to be expanded. New TF bee yard should be placed in the flying range of drones. To maintain versatility and avoid inbreeding nucs are made of all, strong enough hives. Hives, which have given their queen to a nuc, are allowed to raise a new queen for themselves. New queens mate freely in Josef’s plans.
Little by little the modest start will grow into ever largening circle.
Or will it?
In July 2014 bear destroyed my mating nucs in Haukkamaa mating station, which had been in use for 20 years. To be honest the fight with varroa had drained all my strength, bears were just too much. I gave up. I had to think something new, I did not want to take my bees 30 km into the darkest forest and let the bear jeopardise my breeding work. Josef’s idea came to my mind, I decided to give it a go. I thought circumstances in Central Finland would be ideal, few other beekeepers around. I realized we have at least one down side: there are no wild bees in Finland.
Now after 4 years I am ready to share something of what are my ideas of ROOTs breeding system.
These 4 years nearly destroyed my beekeeping. But was the reason ROOTs breeding or 3 rainy and cold summers in a row, that is hard to say.
The main problem is that in the beginning of TF breeding free mating is not working to the advance of TF breeding. The TF hives will raise less, and lower quality drones compared to other hives nearby. Free mating may be good to keep up versatility, but there is no breeding advance. In the contrary: varroa resistance will retard and hives become more mite infested. The bad circle is hard to stop once it has begun.
In the beginning of TF breeding it is essential to mate the best with the best. This can only be done with reliable mating stations or insemination.
FORT KNOX beekeeping, the new initiative from Poland
In April 2018 there was the first European Treatment Free beekeeping conference in Austria. The main interest was captured by the Polish group “Wolne Pszczoly”. A quote from their web site, http://wolnepszczoly.org/about-us/ :
“Fort Knox” is a gold reserve in the USA. That is why we used that name for the reserve of our “gold” – treatment free bees. The initiative is about giving “insurance” for all beekeepers that want to be treatment free, but are afraid of losing hives and start over again. Each beekeeper can declare some of his hives to “joint venture” – whatever number he or she wants, but no more than the number of project members (because we could have some problems of meeting the need in a bad year). We still have these hives in our yards – but they have to be treatment free, “promising” genetics, harvested only from surplus (only from what the bees don’t need for successful wintering – so with no, or only minimum feeding sugar). If a colony dies, beekeeper who is in the common project is given a new colony for free from other beekeeper, who had the luck of surviving bees. We started the initiative a year ago, but this year two of us have already been given colonies from others. We think the initiative in time has the potential to gather more and more beekeepers who would be less frightened by the vision of losing all hives and starting over again. We hope that treatment free, productive bees in time will no longer be the impossible dream in Poland.”
They have a lot in common with Josef Kollers ROOTs breeding: free mating of queens, making nucs of the survivors. But in addition, they prefer 4,9 mm wax or foundations less beehives and minimum sugar feeding and beekeeper intervention.
However, the revolutionary part is the mutual responsibility of other members in the group. Nobody is left alone with no bees in case of losses. The group members live quite far from each other and meet at least once or twice a year to share experiences. In these meetings a member who have lost bees is given new hives (only capped brood frames with bees) from survivor stock of other members.
If beekeepers forming such a group would be living closer to each other, I think the odds were more on favour. After discussing with the project members, it seems to me that they have quite a lot against controlled matings. Their basic main idea is that the natural forces of nature will eventually win, and bees will naturally become varroa resistant when let alone. Their belief is that the impact of treated drones will eventually fade away.
Wild bees of Poland may have positive impact, but on the other hand the enormous density of treated beehives in Poland is serious down side. It remains to be seen what their success will be.
If you know some other initiatives in this matter, or have corrections or comments, please write.
The weather has been hot, maybe a bit too hot…
Kysymykseen on vaikea vastata, koska tällaisia mehiläisiä on olemassa vielä niin kovin vähän, eikä täydellistä liene kehittänyt vielä kukaan. Lisäksi on tiedettävä tarkkaan, puhutaanko puhtaista jalostusyksilöistä vai niiden risteytyksistä. Varroasaastunnan määrä vaikuttaa myös mehiläisten käytökseen. Varmaa lienee vain se, että kun jalostuksella jyrkän valinnan avulla pyritään voimakkaasti edistämään varroankestoa, niin se väistämättä vaikuttaa mehiläisten muihin ominaisuuksiin ainakin lyhyellä tähtäimellä.
Varroankesto perustuu moniin eri tekijöihin, joista tärkeimmät lienevät:
– kuolevien tai kärsivien sikiöiden tunnistaminen kennossa ja niiden poistaminen
– joku muu punkin lisääntymistä hidastava vaikutus (kennojen aukominen, kemiallinen harhautus, punkkien vahingoittaminen)
– mehiläisten kestävyys viruksia vastaan
– joidenkin lähistöllä olevien pesien parempi tai heikompi kestävyys (Kefuss: varroa black holes, Lundén: punkkimagnetismi)
Tähänastisissa tieteellisissä tutkimuksissa on pystytty hyvin yhtenevästi todistamaan, että kaikille punkkia kestäville kannoille on ominaista punkin lisääntymiskyvyn huomattava heikkeneminen. Syitä lisääntymiskyvyn heikkenemiseen on tutkimuksissa pystytty toistaiseksi vain arvailemaan.
Kuolevien tai kärsivien sikiöiden tunnistaminen kennokannen alta ja niiden poistaminen vaikuttaa voimakkaasti pesän maksimikokoon ja kehittymisnopeuteen, jos varroasaastunta on suuri. Mutta entä tulevaisuudessa, voisiko olla, että tarkka ja nopea punkkien tunnistaminen ja välitön poistaminen pitäisivät punkkikannan niin pienenä, että puhdistustyö vaikuttaisi vain vähän yhteiskunnan kokoa pienentävästi? Evoluutiobiologi kysyisi, voisiko varroankeston kustannus mehiläispesälle pienentyä merkityksettömän pieneksi? Muutamat hassut punkit putsattaisiin pois ja kaikki muu pesän toiminta jatkuisi normaalina. Mehiläisten koko genomin selvityksessä havaittiin hajuaistiin liittyvien geenien suuri määrä. Tarkan hajuaistin kääntöpuoli voi olla ympäristön ärsykkeistä hermostuminen, jonka hoitaja voi havaita lievänä vihaisuutena, tai ainakin uteliaana pörräämisenä.
Punkki on sokea ja pesä sisältä melkoisen pimeä paikka. Punkki löytää sopivanikäiset sikiöt hajuaistinsa avulla. Voisiko ajatella, että mehiläiset oppivat harhauttamaan punkkia? Jos sikiöiden erittämä ”kemikaalikoktaili” muuttuisi hieman toisenlaiseksi, se voisi olla tarpeeksi, jotta sokeat punkit eivät löytäisi niitä. Kennojen aukominen ja sulkeminen toiminee sekin eräänlaisena harhautuksena, mutta tiedossani ei ole tämän toimenpiteen tehokkuus. Maalaisjärjellä ajatellen voiko punkki olla niin tyhmä, että pelkkä kennon kannen avaaminen saisi sen nousemaan ylös kennon pohjalta sikiön alta kesken lisääntymisprosessin? En usko, mutta tämäkin vaikutus voi perustua kemiaan: kennon sisäisten kaasujen koostumus muuttuu ja punkin lisääntymisen pasmat menevät sekaisin. Viimeaikaiset tutkimukset Apis ceranalla osoittavat että punkit vastoin aiempaa luuloa pystyvät lisääntymään työläiskennoissa, mutta putsaaminen on niin tehokasta, että niitä ei ole aiemmin löydetty. Tämä on mielenkiintoinen tulos, joka antaa uskoa siihen, että myös melliferalla tämä voisi toimia päämekanismina punkkia vastaan.
Punkin fyysinen vahingoittaminen on aivan oma juttunsa, johon ainakin Alois Wallner on tutkimuksissaan ja jalostustyössään keskittynyt. Wallner pystyy tällä hetkellä tulemaan toimeen yhdellä muurahaishappo torjunnalla, mikä on Keski-Euroopan oloissa huomattava saavutus. Myös USA:ssa on ajoittain kohistu ns. Anckle Biter eli nilkanpurija mehiläisistä. Näitä on jalostanut Purduen Yliopisto.
Mehiläisten viruskesto on tavallaan vakuutus, joka varmistaa, että jos punkin torjunta on syystä tai toisesta jäänyt huonoksi, niin pesä ei silti tuhoudu, koska mehiläiset kestävät punkin tuomien ja levittämien virusten vaikutuksia. Mehiläisethän eivät kuole punkkiin vaan punkin levittämiin viruksiin. Tämä on paradoksi, jota pitää hetki miettiä. Jos mehiläiset eivät kuole punkkiin vaan viruksiin niin voisiko olla niin, että virukset muuttuvat heikommiksi? Näin eräs tiedemiesryhmä uskoi englantilaiset Ron Hoskinssin tapauksessa. Hänen pesistään löydettiin DWV eli siivenkutistajaviruksen B kantaa, jonka uskottiin olevan pesien selviämisen salaisuus, vaikka Ron Hoskins oli kahdenkymmenen vuoden ajan jalostanut punkkia kestävää mehiläistä. Puhuttiin ns. super-infection exclusionista, eli kun pesille vähemmän vaarallinen virus pääsee syystä tai toisesta lisääntymään pesässä, se ikään kuin sulkee vahingolliset virukset pesän ulkopuolelle. No, kuten tieteessä usein tapahtuu, toinen tutkimus kumosi tämän teorian. Kun tutkittiin koko Englannin viruskantoja, huomattiin, että B kanta oli hallitsevana valtaosassa tutkituista kohteista. Osa tiedeyhteisöstä on lisäksi sitä mieltä, että B kanta on nimenomaan se vaarallisempi versio.
Itävallassa huhtikuun alussa pidetyssä ensimmäisessä eurooppalaisessa kansainvälisessä konferenssissa, jonka aiheena oli mehiläishoito ilman varroan torjuntaa, esitti John Kefuss käsitteen ”varroa black hole”. Johnin englannin kieli on melkoisen haastavaa seurattavaa, saksan ja ranskan kielen sanat sekoittuvat mukaan, mutta sikäli kun ymmärsin oikein, niin hänen sanomansa oli, että punkkia kestävä pesä toimii kuin musta aukko, josta punkki ei elävänä palaa. Kestävä pesä siis auttaa ympäristöään pysymään hengissä. Raportoin samasta asiasta toisinpäin vuonna 2003: Jotkut pesät tuntuvat imevän punkkeja itseensä kuin magneetti. Tästä on seurauksena, että ne kuolevat, mutta se helpottaa muiden pesien tilannetta. Tämä on luonnon monimuotoisuutta ja normaalia luonnonvalintaa. Luonnonvoimen avulla syntyvä tasapaino voi olla jotain täysin muuta kuin se, mihin jalostuksella pyritään. Luonnon tasapainotilanteessa lajille riittää hengissä pysyminen, populaation koon jatkuva kasvu ei ole mahdollista (vrt. ihmiskunta!). Luonnonvalinnalle riittää, että jos joka pesä parveilee joka vuosi, niin kuolleisuus voi olla 50%. Jalostaja taas haluaa, että kaikki pesät pysyvät hengissä.
Haastetta riittää. Suurimman ahaaelämyksen varroan keston jalostaja saa sinä hetkenä, kun hän lopullisesti uskoo ja ymmärtää, että mehiläiset eivät kuole punkkiin. Voin kertoa, että se on mahtava hetki. Ja samalla saa uuden ystävän, tai oikeastaan tuhansia, punkin, jota tarvitaan jalostustyössä.